Otapanje leda na polovima

[Barbarin]

I mi se đubrimo iz Afrike.

[ALEKSIJE D.]

Gledao sam neku emisiju, klasičan oblik edukacije, gde se za ozonksi omotač krive-krave! Mnogo, brate, balegaju i stvaraju metan.
Čini mi kako je Milanković nešto u "Kanonima osunčavanja" objasnio gde dolazi do zamene polova na svakoh par desetina hiljada godina.
To bi trebao neko ko se bavi egzaktnim naukama objasni, a ne palamudi ko mi.

[Gaff]

Could a Penny Battery Power a House?

(via Wired)

Eto! Skupo, smrdi, zauzima mnogo mesta, al' radi...

http://www.wired.com/wiredscience/2012/09/could-a-penny-battery-power-a-house/



A može i ovako:


Making of a cow-dung battery (a Bio battery)

[Gaff]

Cleaning up oil spills with magnets at MIT

Cleaning up oil spills with magnets at MIT

[scallop]

Neka to probaju u Golfu. Nije ni za krivi, osim oko Floride.

[Meho Krljic]

Vetar je više nego dovoljan izvor energije dovoljan za čitavu planetu puta 200, ako uzmemo trenutnu konzumaciju energije kao meru. Sem što bi vetrenjače trebalo staviti visoko iznad zemlje, 200 metara do 20 kilometara visoko...

Forget Aeolians, We Need Airborne Wind Farms To Harness Maximum Wind Energy

The wind holds much promise for our energy worries, considering that it's a renewable resource. But not only has it yet to fulfil its portion of the renewable energy hype, optimistic projections of wind-generated energy are just that... optimistic. The US Department of Energy, for instance, estimates that by 2030, only a 20% share of the country's electricity production will be generated from wind energy (pdfreport).

This uninspiring estimate though, does no justice to the amount of power scientists now believe can be harnessed from the wind. A new paper, published this weekend in Nature Climate Change, used a model which considered the theoreticallimits of energy extraction from the wind to postulate some astonishing results. Low-altitude winds near Earth's surface hold at least 400 TW of power. But go higher up to altitudes between 200 m and 20 km and the winds confine a massive 1,800 TW, at least. Such an extraordinary amount of power can sustain an equivalent of 200 Earth habitations (Earth's global energy demand is 18 TW)!

Attempting to harness wind power at dizzying heights appears to be an attractive proposition. High-altitude winds are faster and as such, comprise more power. Power is proportional to the cube of velocity. This means that if wind velocity doubles, wind power grows by eight times. In addition, high-altitude winds are also steadier and more predictable.

A report published last year by GL Garrad Hassan, an independent renewable energy consultancy, shows that a number of companies are indeed focusing on harnessing high-altitude wind energy. Prototypes are varied and range from kites and kytoons (which are basically kites which are lifted and held in position by balloons) to aerostats and gliders with turbines attached.


To harness wind energy, the wind's kinetic energy (or energy of motion) must be turned to mechanical energy (the spinning turbines) which should in turn be converted into electrical energy (by the turbines). The kite mechanism follows this pathway in an uncomplicated manner. The kite, tethered to the ground, rises to the heavens to meet high-altitude winds. Once floating at high speeds, the turbines fixed to the kite convert the kinetic energy of high-altitude winds into mechanical and then electrical energy. This is transmitted via the attaching conducting material back to the ground and immediately off to power homes, etcetera.

While it is attractive from a theoretical and technological viewpoint to set up wind farms at kilometres of altitude, it may not actually be feasible. For one, as George Dvorsky at io9 pointsout, the paper only looked at the theoretical limits of energy-harnessing from the wind without considering any other practical factors:
"The focus of their research was to determine the geophysical limits of energy extraction from the Earth's wind, disregarding such things as economic, social or environmental factors."

The paper itself also comes with a clear note of caution which emphasizes the theoretical focus of the study:
"It is likely that wind power growth will be limited by economic or environmental factors, not global geophysical limits."

Irrespective of this, the paper should provide a major boost to backers of wind-generated energy. Because science has confirmed that the sky's the limit.

--

Reference:
Marvel, K., Kravitz, B. & Caldeira, K. (2012) Geophysical limits to global wind power. Nature Climate Change. DOI: 10.1038/nclimate1683.

[Truba]

oće li i ova zima biti sa metar snijega kao prethodna???? 

[Meho Krljic]

Rekordi su gadna stvar:

Press Release: Arctic sea ice reaches lowest extent for the year and the satellite record

[noae]

The National Snow and Ice Data Center (NSIDC) is part of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. NSIDC scientists provide Arctic Sea Ice News & Analysis content, with partial support from NASA.
BOULDER, Colorado—Arctic sea ice cover likely melted to its minimum extent for the year on September 16, according to scientists at the National Snow and Ice Data Center (NSIDC). Sea ice extent fell to 3.41 million square kilometers (1.32 million square miles), now the lowest summer minimum extent in the satellite record.
"We are now in uncharted territory," said NSIDC Director Mark Serreze. "While we've long known that as the planet warms up, changes would be seen first and be most pronounced in the Arctic, few of us were prepared for how rapidly the changes would actually occur."Arctic sea ice cover grows each winter as the sun sets for several months, and shrinks each summer as the sun rises higher in the northern sky. Each year, the Arctic sea ice reaches its minimum extent in September. This year's minimum follows a record-breaking summer of low sea ice extents in the Arctic. Sea ice extent fell to 4.10 million square kilometers (1.58 million square miles) on August 26, breaking the lowest extent on record set on September 18, 2007 of 4.17 million square kilometers (1.61 million square miles). On September 4, it fell below 4.00 million square kilometers (1.54 million square miles), another first in the 33-year satellite record.
"The strong late season decline is indicative of how thin the ice cover is," said NSIDC scientist Walt Meier. "Ice has to be quite thin to continue melting away as the sun goes down and fall approaches."
NSIDC scientists have observed fundamental changes in the Arctic's sea ice cover. The Arctic used to be dominated by multiyear ice, or ice that survived through several years. Lately, the Arctic is increasingly characterized by seasonal ice cover and large areas are now prone to completely melt away in summer.
"The later minimum date is somewhat surprising because we expected that the late melt in the Chukchi and East Siberian seas would result in cool surface waters that would quickly refreeze once the atmosphere cooled," Meier said. "However, ice loss continued north of the Laptev Sea, opening up a gap in the ice cover that reduced extent."
Arctic sea ice has long been recognized as a sensitive climate indicator. The region's sea ice extent--defined by NSIDC as the total area covered by at least 15 percent of ice—varies from year to year because of changeable weather conditions. However, ice extent has shown a dramatic overall decline over the past thirty years. This year's minimum will be nearly 50 percent lower than the 1979 to 2000 average.
NSIDC lead scientist Ted Scambos said that thinning ice, along with early loss of snow, are rapidly warming the Arctic. "But a wider impact may come from the increased heat and moisture the warmer Arctic is adding to the climate system," he said. "This will gradually affect climate in the areas where we live," he added. "We have a less polar pole—and so there will be more variations and extremes."
NSIDC scientist Julienne Stroeve said, "Recent climate models suggest that ice-free conditions may happen before 2050, though the observed rate of decline remains faster than many of the models are able to capture."
Serreze said, "While lots of people talk about opening of the Northwest Passage through the Canadian Arctic islands and the Northern Sea Route along the Russian coast, twenty years from now from now in August you might be able to take a ship right across the Arctic Ocean."
For more details on the minimum ice extent, see the Arctic Sea Ice News and Analysis Web site. The site provides regular updates by NSIDC scientists on the condition of the Arctic sea ice.
Please note that this number is preliminary--changing weather conditions could still push the ice extent lower. During the first week of October, NSIDC will issue a full analysis of the possible causes behind this year's ice conditions, including a discussion of how the summer's low ice extent may affect the winter ice growth season ahead, and graphics comparing this year to the long-term record.
Information and graphicsFor the scientific report and data images, please see NSIDC's Arctic Sea Ice News and Analysis.
A news release by NASA is available at http://www.nasa.gov/topics/earth/features/2012-seaicemin.html
NASA's image of the September 16 minimum may be downloaded here: http://svs.gsfc.nasa.gov/vis/a000000/a003900/a003998/Minimum_SeaIce_Area_2012_09_16.1080.tif
Contact: Natasha Vizcarra
  National Snow and Ice Data Center
  University of Colorado Boulder
  (303) 492-1497
natasha.vizcarra@nsidc.org

[/noae]

A za seksepilnije napisan, ali jednako zastrašujući tekst, imamo Roling Stoun:Global Warming's Terrifying New MathThree simple numbers that add up to global catastrophe - and that make clear who the real enemy is

[noae]

By Bill McKibben July 19, 2012 9:35 AM ET If the pictures of those towering wildfires in Colorado haven't convinced you, or the size of your AC bill this summer, here are some hard numbers about climate change: June broke or tied 3,215 high-temperature records across the United States. That followed the warmest May on record for the Northern Hemisphere – the 327th consecutive month in which the temperature of the entire globe exceeded the 20th-century average, the odds of which occurring by simple chance were 3.7 x 10-99, a number considerably larger than the number of stars in the universe.
Meteorologists reported that this spring was the warmest ever recorded for our nation – in fact, it crushed the old record by so much that it represented the "largest temperature departure from average of any season on record." The same week, Saudi authorities reported that it had rained in Mecca despite a temperature of 109 degrees, the hottest downpour in the planet's history.
Not that our leaders seemed to notice. Last month the world's nations, meeting in Rio for the 20th-anniversary reprise of a massive 1992 environmental summit, accomplished nothing. Unlike George H.W. Bush, who flew in for the first conclave, Barack Obama didn't even attend. It was "a ghost of the glad, confident meeting 20 years ago," the British journalist George Monbiot wrote; no one paid it much attention, footsteps echoing through the halls "once thronged by multitudes." Since I wrote one of the first books for a general audience about global warming way back in 1989, and since I've spent the intervening decades working ineffectively to slow that warming, I can say with some confidence that we're losing the fight, badly and quickly – losing it because, most of all, we remain in denial about the peril that human civilization is in.
When we think about global warming at all, the arguments tend to be ideological, theological and economic. But to grasp the seriousness of our predicament, you just need to do a little math. For the past year, an easy and powerful bit of arithmetical analysis first published by financial analysts in the U.K. has been making the rounds of environmental conferences and journals, but it hasn't yet broken through to the larger public. This analysis upends most of the conventional political thinking about climate change. And it allows us to understand our precarious – our almost-but-not-quite-finally hopeless – position with three simple numbers.
The First Number: 2° Celsius
If the movie had ended in Hollywood fashion, the Copenhagen climate conference in 2009 would have marked the culmination of the global fight to slow a changing climate. The world's nations had gathered in the December gloom of the Danish capital for what a leading climate economist, Sir Nicholas Stern of Britain, called the "most important gathering since the Second World War, given what is at stake." As Danish energy minister Connie Hedegaard, who presided over the conference, declared at the time: "This is our chance. If we miss it, it could take years before we get a new and better one. If ever."
In the event, of course, we missed it. Copenhagen failed spectacularly. Neither China nor the United States, which between them are responsible for 40 percent of global carbon emissions, was prepared to offer dramatic concessions, and so the conference drifted aimlessly for two weeks until world leaders jetted in for the final day. Amid considerable chaos, President Obama took the lead in drafting a face-saving "Copenhagen Accord" that fooled very few. Its purely voluntary agreements committed no one to anything, and even if countries signaled their intentions to cut carbon emissions, there was no enforcement mechanism. "Copenhagen is a crime scene tonight," an angry Greenpeace official declared, "with the guilty men and women fleeing to the airport." Headline writers were equally brutal: COPENHAGEN: THE MUNICH OF OUR TIMES? asked one.
The accord did contain one important number, however. In Paragraph 1, it formally recognized "the scientific view that the increase in global temperature should be below two degrees Celsius." And in the very next paragraph, it declared that "we agree that deep cuts in global emissions are required... so as to hold the increase in global temperature below two degrees Celsius." By insisting on two degrees – about 3.6 degrees Fahrenheit – the accord ratified positions taken earlier in 2009 by the G8, and the so-called Major Economies Forum. It was as conventional as conventional wisdom gets. The number first gained prominence, in fact, at a 1995 climate conference chaired by Angela Merkel, then the German minister of the environment and now the center-right chancellor of the nation.
Some context: So far, we've raised the average temperature of the planet just under 0.8 degrees Celsius, and that has caused far more damage than most scientists expected. (A third of summer sea ice in the Arctic is gone, the oceans are 30 percent more acidic, and since warm air holds more water vapor than cold, the atmosphere over the oceans is a shocking five percent wetter, loading the dice for devastating floods.) Given those impacts, in fact, many scientists have come to think that two degrees is far too lenient a target. "Any number much above one degree involves a gamble," writes Kerry Emanuel of MIT, a leading authority on hurricanes, "and the odds become less and less favorable as the temperature goes up." Thomas Lovejoy, once the World Bank's chief biodiversity adviser, puts it like this: "If we're seeing what we're seeing today at 0.8 degrees Celsius, two degrees is simply too much." NASA scientist James Hansen, the planet's most prominent climatologist, is even blunter: "The target that has been talked about in international negotiations for two degrees of warming is actually a prescription for long-term disaster." At the Copenhagen summit, a spokesman for small island nations warned that many would not survive a two-degree rise: "Some countries will flat-out disappear." When delegates from developing nations were warned that two degrees would represent a "suicide pact" for drought-stricken Africa, many of them started chanting, "One degree, one Africa."
Despite such well-founded misgivings, political realism bested scientific data, and the world settled on the two-degree target – indeed, it's fair to say that it's the only thing about climate change the world has settled on. All told, 167 countries responsible for more than 87 percent of the world's carbon emissions have signed on to the Copenhagen Accord, endorsing the two-degree target. Only a few dozen countries have rejected it, including Kuwait, Nicaragua and Venezuela. Even the United Arab Emirates, which makes most of its money exporting oil and gas, signed on. The official position of planet Earth at the moment is that we can't raise the temperature more than two degrees Celsius – it's become the bottomest of bottom lines. Two degrees.



The Second Number: 565 Gigatons

[/size]Scientists estimate that humans can pour roughly 565 more gigatons of carbon dioxide into the atmosphere by midcentury and still have some reasonable hope of staying below two degrees. ("Reasonable," in this case, means four chances in five, or somewhat worse odds than playing Russian roulette with a six-shooter.)

This idea of a global "carbon budget" emerged about a decade ago, as scientists began to calculate how much oil, coal and gas could still safely be burned. Since we've increased the Earth's temperature by 0.8 degrees so far, we're currently less than halfway to the target. But, in fact, computer models calculate that even if we stopped increasing CO₂ now, the temperature would likely still rise another 0.8 degrees, as previously released carbon continues to overheat the atmosphere. That means we're already three-quarters of the way to the two-degree target.

How good are these numbers? No one is insisting that they're exact, but few dispute that they're generally right. The 565-gigaton figure was derived from one of the most sophisticated computer-simulation models that have been built by climate scientists around the world over the past few decades. And the number is being further confirmed by the latest climate-simulation models currently being finalized in advance of the next report by the Intergovernmental Panel on Climate Change. "Looking at them as they come in, they hardly differ at all," says Tom Wigley, an Australian climatologist at the National Center for Atmospheric Research. "There's maybe 40 models in the data set now, compared with 20 before. But so far the numbers are pretty much the same. We're just fine-tuning things. I don't think much has changed over the last decade." William Collins, a senior climate scientist at the Lawrence Berkeley National Laboratory, agrees. "I think the results of this round of simulations will be quite similar," he says. "We're not getting any free lunch from additional understanding of the climate system."

We're not getting any free lunch from the world's economies, either. With only a single year's lull in 2009 at the height of the financial crisis, we've continued to pour record amounts of carbon into the atmosphere, year after year. In late May, the International Energy Agency published its latest figures – CO₂ emissions last year rose to 31.6 gigatons, up 3.2 percent from the year before. America had a warm winter and converted more coal-fired power plants to natural gas, so its emissions fell slightly; China kept booming, so its carbon output (which recently surpassed the U.S.) rose 9.3 percent; the Japanese shut down their fleet of nukes post-Fukushima, so their emissions edged up 2.4 percent. "There have been efforts to use more renewable energy and improve energy efficiency," said Corinne Le Quéré, who runs England's Tyndall Centre for Climate Change Research. "But what this shows is that so far the effects have been marginal." In fact, study after study predicts that carbon emissions will keep growing by roughly three percent a year – and at that rate, we'll blow through our 565-gigaton allowance in 16 years, around the time today's preschoolers will be graduating from high school. "The new data provide further evidence that the door to a two-degree trajectory is about to close," said Fatih Birol, the IEA's chief economist. In fact, he continued, "When I look at this data, the trend is perfectly in line with a temperature increase of about six degrees." That's almost 11 degrees Fahrenheit, which would create a planet straight out of science fiction.

So, new data in hand, everyone at the Rio conference renewed their ritual calls for serious international action to move us back to a two-degree trajectory. The charade will continue in November, when the next Conference of the Parties (COP) of the U.N. Framework Convention on Climate Change convenes in Qatar. This will be COP 18 – COP 1 was held in Berlin in 1995, and since then the process has accomplished essentially nothing. Even scientists, who are notoriously reluctant to speak out, are slowly overcoming their natural preference to simply provide data. "The message has been consistent for close to 30 years now," Collins says with a wry laugh, "and we have the instrumentation and the computer power required to present the evidence in detail. If we choose to continue on our present course of action, it should be done with a full evaluation of the evidence the scientific community has presented." He pauses, suddenly conscious of being on the record. "I should say, a fuller evaluation of the evidence."

So far, though, such calls have had little effect. We're in the same position we've been in for a quarter-century: scientific warning followed by political inaction. Among scientists speaking off the record, disgusted candor is the rule. One senior scientist told me, "You know those new cigarette packs, where governments make them put a picture of someone with a hole in their throats? Gas pumps should have something like that."

The Third Number: 2,795 Gigatons

[/size]This number is the scariest of all – one that, for the first time, meshes the political and scientific dimensions of our dilemma. It was highlighted last summer by the Carbon Tracker Initiative, a team of London financial analysts and environmentalists who published a report in an effort to educate investors about the possible risks that climate change poses to their stock portfolios. The number describes the amount of carbon already contained in the proven coal and oil and gas reserves of the fossil-fuel companies, and the countries (think Venezuela or Kuwait) that act like fossil-fuel companies. In short, it's the fossil fuel we're currently planning to burn. And the key point is that this new number – 2,795 – is higher than 565. Five times higher.

The Carbon Tracker Initiative – led by James Leaton, an environmentalist who served as an adviser at the accounting giant PricewaterhouseCoopers – combed through proprietary databases to figure out how much oil, gas and coal the world's major energy companies hold in reserve. The numbers aren't perfect – they don't fully reflect the recent surge in unconventional energy sources like shale gas, and they don't accurately reflect coal reserves, which are subject to less stringent reporting requirements than oil and gas. But for the biggest companies, the figures are quite exact: If you burned everything in the inventories of Russia's Lukoil and America's ExxonMobil, for instance, which lead the list of oil and gas companies, each would release more than 40 gigatons of carbon dioxide into the atmosphere.

Which is exactly why this new number, 2,795 gigatons, is such a big deal. Think of two degrees Celsius as the legal drinking limit – equivalent to the 0.08 blood-alcohol level below which you might get away with driving home. The 565 gigatons is how many drinks you could have and still stay below that limit – the six beers, say, you might consume in an evening. And the 2,795 gigatons? That's the three 12-packs the fossil-fuel industry has on the table, already opened and ready to pour.

We have five times as much oil and coal and gas on the books as climate scientists think is safe to burn. We'd have to keep 80 percent of those reserves locked away underground to avoid that fate. Before we knew those numbers, our fate had been likely. Now, barring some massive intervention, it seems certain.

Yes, this coal and gas and oil is still technically in the soil. But it's already economically aboveground – it's figured into share prices, companies are borrowing money against it, nations are basing their budgets on the presumed returns from their patrimony. It explains why the big fossil-fuel companies have fought so hard to prevent the regulation of carbon dioxide – those reserves are their primary asset, the holding that gives their companies their value. It's why they've worked so hard these past years to figure out how to unlock the oil in Canada's tar sands, or how to drill miles beneath the sea, or how to frack the Appalachians.



If you told Exxon or Lukoil that, in order to avoid wrecking the climate, they couldn't pump out their reserves, the value of their companies would plummet. John Fullerton, a former managing director at JP Morgan who now runs the Capital Institute, calculates that at today's market value, those 2,795 gigatons of carbon emissions are worth about $27 trillion. Which is to say, if you paid attention to the scientists and kept 80 percent of it underground, you'd be writing off $20 trillion in assets. The numbers aren't exact, of course, but that carbon bubble makes the housing bubble look small by comparison. It won't necessarily burst – we might well burn all that carbon, in which case investors will do fine. But if we do, the planet will crater. You can have a healthy fossil-fuel balance sheet, or a relatively healthy planet – but now that we know the numbers, it looks like you can't have both. Do the math: 2,795 is five times 565. That's how the story ends.

[/size]So far, as I said at the start, environmental efforts to tackle global warming have failed. The planet's emissions of carbon dioxide continue to soar, especially as developing countries emulate (and supplant) the industries of the West. Even in rich countries, small reductions in emissions offer no sign of the real break with the status quo we'd need to upend the iron logic of these three numbers. Germany is one of the only big countries that has actually tried hard to change its energy mix; on one sunny Saturday in late May, that northern-latitude nation generated nearly half its power from solar panels within its borders. That's a small miracle – and it demonstrates that we have the technology to solve our problems. But we lack the will. So far, Germany's the exception; the rule is ever more carbon.

This record of failure means we know a lot about what strategies don't work. Green groups, for instance, have spent a lot of time trying to change individual lifestyles: the iconic twisty light bulb has been installed by the millions, but so have a new generation of energy-sucking flatscreen TVs. Most of us are fundamentally ambivalent about going green: We like cheap flights to warm places, and we're certainly not going to give them up if everyone else is still taking them. Since all of us are in some way the beneficiaries of cheap fossil fuel, tackling climate change has been like trying to build a movement against yourself – it's as if the gay-rights movement had to be constructed entirely from evangelical preachers, or the abolition movement from slaveholders.

People perceive – correctly – that their individual actions will not make a decisive difference in the atmospheric concentration of CO2; by 2010, a poll found that "while recycling is widespread in America and 73 percent of those polled are paying bills online in order to save paper," only four percent had reduced their utility use and only three percent had purchased hybrid cars. Given a hundred years, you could conceivably change lifestyles enough to matter – but time is precisely what we lack.

A more efficient method, of course, would be to work through the political system, and environmentalists have tried that, too, with the same limited success. They've patiently lobbied leaders, trying to convince them of our peril and assuming that politicians would heed the warnings. Sometimes it has seemed to work. Barack Obama, for instance, campaigned more aggressively about climate change than any president before him – the night he won the nomination, he told supporters that his election would mark the moment "the rise of the oceans began to slow and the planet began to heal." And he has achieved one significant change: a steady increase in the fuel efficiency mandated for automobiles. It's the kind of measure, adopted a quarter-century ago, that would have helped enormously. But in light of the numbers I've just described, it's obviously a very small start indeed.

At this point, effective action would require actually keeping most of the carbon the fossil-fuel industry wants to burn safely in the soil, not just changing slightly the speed at which it's burned. And there the president, apparently haunted by the still-echoing cry of "Drill, baby, drill," has gone out of his way to frack and mine. His secretary of interior, for instance, opened up a huge swath of the Powder River Basin in Wyoming for coal extraction: The total basin contains some 67.5 gigatons worth of carbon (or more than 10 percent of the available atmospheric space). He's doing the same thing with Arctic and offshore drilling; in fact, as he explained on the stump in March, "You have my word that we will keep drilling everywhere we can... That's a commitment that I make." The next day, in a yard full of oil pipe in Cushing, Oklahoma, the president promised to work on wind and solar energy but, at the same time, to speed up fossil-fuel development: "Producing more oil and gas here at home has been, and will continue to be, a critical part of an all-of-the-above energy strategy." That is, he's committed to finding even more stock to add to the 2,795-gigaton inventory of unburned carbon.

Sometimes the irony is almost Borat-scale obvious: In early June, Secretary of State Hillary Clinton traveled on a Norwegian research trawler to see firsthand the growing damage from climate change. "Many of the predictions about warming in the Arctic are being surpassed by the actual data," she said, describing the sight as "sobering." But the discussions she traveled to Scandinavia to have with other foreign ministers were mostly about how to make sure Western nations get their share of the estimated $9 trillion in oil (that's more than 90 billion barrels, or 37 gigatons of carbon) that will become accessible as the Arctic ice melts. Last month, the Obama administration indicated that it would give Shell permission to start drilling in sections of the Arctic.

Almost every government with deposits of hydrocarbons straddles the same divide. Canada, for instance, is a liberal democracy renowned for its internationalism – no wonder, then, that it signed on to the Kyoto treaty, promising to cut its carbon emissions substantially by 2012. But the rising price of oil suddenly made the tar sands of Alberta economically attractive – and since, as NASA climatologist James Hansen pointed out in May, they contain as much as 240 gigatons of carbon (or almost half of the available space if we take the 565 limit seriously), that meant Canada's commitment to Kyoto was nonsense. In December, the Canadian government withdrew from the treaty before it faced fines for failing to meet its commitments.

The same kind of hypocrisy applies across the ideological board: In his speech to the Copenhagen conference, Venezuela's Hugo Chavez quoted Rosa Luxemburg, Jean-Jacques Rousseau and "Christ the Redeemer," insisting that "climate change is undoubtedly the most devastating environmental problem of this century." But the next spring, in the Simon Bolivar Hall of the state-run oil company, he signed an agreement with a consortium of international players to develop the vast Orinoco tar sands as "the most significant engine for a comprehensive development of the entire territory and Venezuelan population." The Orinoco deposits are larger than Alberta's – taken together, they'd fill up the whole available atmospheric space.

[/size]So: the paths we have tried to tackle global warming have so far produced only gradual, halting shifts. A rapid, transformative change would require building a movement, and movements require enemies. As John F. Kennedy put it, "The civil rights movement should thank God for Bull Connor. He's helped it as much as Abraham Lincoln." And enemies are what climate change has lacked.

But what all these climate numbers make painfully, usefully clear is that the planet does indeed have an enemy – one far more committed to action than governments or individuals. Given this hard math, we need to view the fossil-fuel industry in a new light. It has become a rogue industry, reckless like no other force on Earth. It is Public Enemy Number One to the survival of our planetary civilization. "Lots of companies do rotten things in the course of their business – pay terrible wages, make people work in sweatshops – and we pressure them to change those practices," says veteran anti-corporate leader Naomi Klein, who is at work on a book about the climate crisis. "But these numbers make clear that with the fossil-fuel industry, wrecking the planet is their business model. It's what they do."

According to the Carbon Tracker report, if Exxon burns its current reserves, it would use up more than seven percent of the available atmospheric space between us and the risk of two degrees. BP is just behind, followed by the Russian firm Gazprom, then Chevron, ConocoPhillips and Shell, each of which would fill between three and four percent. Taken together, just these six firms, of the 200 listed in the Carbon Tracker report, would use up more than a quarter of the remaining two-degree budget. Severstal, the Russian mining giant, leads the list of coal companies, followed by firms like BHP Billiton and Peabody. The numbers are simply staggering – this industry, and this industry alone, holds the power to change the physics and chemistry of our planet, and they're planning to use it.

They're clearly cognizant of global warming – they employ some of the world's best scientists, after all, and they're bidding on all those oil leases made possible by the staggering melt of Arctic ice. And yet they relentlessly search for more hydrocarbons – in early March, Exxon CEO Rex Tillerson told Wall Street analysts that the company plans to spend $37 billion a year through 2016 (about $100 million a day) searching for yet more oil and gas.



There's not a more reckless man on the planet than Tillerson. Late last month, on the same day the Colorado fires reached their height, he told a New York audience that global warming is real, but dismissed it as an "engineering problem" that has "engineering solutions." Such as? "Changes to weather patterns that move crop-production areas around – we'll adapt to that." This in a week when Kentucky farmers were reporting that corn kernels were "aborting" in record heat, threatening a spike in global food prices. "The fear factor that people want to throw out there to say, 'We just have to stop this,' I do not accept," Tillerson said. Of course not – if he did accept it, he'd have to keep his reserves in the ground. Which would cost him money. It's not an engineering problem, in other words – it's a greed problem.

You could argue that this is simply in the nature of these companies – that having found a profitable vein, they're compelled to keep mining it, more like efficient automatons than people with free will. But as the Supreme Court has made clear, they are people of a sort. In fact, thanks to the size of its bankroll, the fossil-fuel industry has far more free will than the rest of us. These companies don't simply exist in a world whose hungers they fulfill – they help create the boundaries of that world.

Left to our own devices, citizens might decide to regulate carbon and stop short of the brink; according to a recent poll, nearly two-thirds of Americans would back an international agreement that cut carbon emissions 90 percent by 2050. But we aren't left to our own devices. The Koch brothers, for instance, have a combined wealth of $50 billion, meaning they trail only Bill Gates on the list of richest Americans. They've made most of their money in hydrocarbons, they know any system to regulate carbon would cut those profits, and they reportedly plan to lavish as much as $200 million on this year's elections. In 2009, for the first time, the U.S. Chamber of Commerce surpassed both the Republican and Democratic National Committees on political spending; the following year, more than 90 percent of the Chamber's cash went to GOP candidates, many of whom deny the existence of global warming. Not long ago, the Chamber even filed a brief with the EPA urging the agency not to regulate carbon – should the world's scientists turn out to be right and the planet heats up, the Chamber advised, "populations can acclimatize to warmer climates via a range of behavioral, physiological and technological adaptations." As radical goes, demanding that we change our physiology seems right up there.

Environmentalists, understandably, have been loath to make the fossil-fuel industry their enemy, respecting its political power and hoping instead to convince these giants that they should turn away from coal, oil and gas and transform themselves more broadly into "energy companies." Sometimes that strategy appeared to be working – emphasis on appeared. Around the turn of the century, for instance, BP made a brief attempt to restyle itself as "Beyond Petroleum," adapting a logo that looked like the sun and sticking solar panels on some of its gas stations. But its investments in alternative energy were never more than a tiny fraction of its budget for hydrocarbon exploration, and after a few years, many of those were wound down as new CEOs insisted on returning to the company's "core business." In December, BP finally closed its solar division. Shell shut down its solar and wind efforts in 2009. The five biggest oil companies have made more than $1 trillion in profits since the millennium – there's simply too much money to be made on oil and gas and coal to go chasing after zephyrs and sunbeams.

Much of that profit stems from a single historical accident: Alone among businesses, the fossil-fuel industry is allowed to dump its main waste, carbon dioxide, for free. Nobody else gets that break – if you own a restaurant, you have to pay someone to cart away your trash, since piling it in the street would breed rats. But the fossil-fuel industry is different, and for sound historical reasons: Until a quarter-century ago, almost no one knew that CO2 was dangerous. But now that we understand that carbon is heating the planet and acidifying the oceans, its price becomes the central issue.

If you put a price on carbon, through a direct tax or other methods, it would enlist markets in the fight against global warming. Once Exxon has to pay for the damage its carbon is doing to the atmosphere, the price of its products would rise. Consumers would get a strong signal to use less fossil fuel – every time they stopped at the pump, they'd be reminded that you don't need a semimilitary vehicle to go to the grocery store. The economic playing field would now be a level one for nonpolluting energy sources. And you could do it all without bankrupting citizens – a so-called "fee-and-dividend" scheme would put a hefty tax on coal and gas and oil, then simply divide up the proceeds, sending everyone in the country a check each month for their share of the added costs of carbon. By switching to cleaner energy sources, most people would actually come out ahead.

There's only one problem: Putting a price on carbon would reduce the profitability of the fossil-fuel industry. After all, the answer to the question "How high should the price of carbon be?" is "High enough to keep those carbon reserves that would take us past two degrees safely in the ground." The higher the price on carbon, the more of those reserves would be worthless. The fight, in the end, is about whether the industry will succeed in its fight to keep its special pollution break alive past the point of climate catastrophe, or whether, in the economists' parlance, we'll make them internalize those externalities.

[/size]It's not clear, of course, that the power of the fossil-fuel industry can be broken. The U.K. analysts who wrote the Carbon Tracker report and drew attention to these numbers had a relatively modest goal – they simply wanted to remind investors that climate change poses a very real risk to the stock prices of energy companies. Say something so big finally happens (a giant hurricane swamps Manhattan, a megadrought wipes out Midwest agriculture) that even the political power of the industry is inadequate to restrain legislators, who manage to regulate carbon. Suddenly those Chevron reserves would be a lot less valuable, and the stock would tank. Given that risk, the Carbon Tracker report warned investors to lessen their exposure, hedge it with some big plays in alternative energy.

"The regular process of economic evolution is that businesses are left with stranded assets all the time," says Nick Robins, who runs HSBC's Climate Change Centre. "Think of film cameras, or typewriters. The question is not whether this will happen. It will. Pension systems have been hit by the dot-com and credit crunch. They'll be hit by this." Still, it hasn't been easy to convince investors, who have shared in the oil industry's record profits. "The reason you get bubbles," sighs Leaton, "is that everyone thinks they're the best analyst – that they'll go to the edge of the cliff and then jump back when everyone else goes over."

So pure self-interest probably won't spark a transformative challenge to fossil fuel. But moral outrage just might – and that's the real meaning of this new math. It could, plausibly, give rise to a real movement.

Once, in recent corporate history, anger forced an industry to make basic changes. That was the campaign in the 1980s demanding divestment from companies doing business in South Africa. It rose first on college campuses and then spread to municipal and state governments; 155 campuses eventually divested, and by the end of the decade, more than 80 cities, 25 states and 19 counties had taken some form of binding economic action against companies connected to the apartheid regime. "The end of apartheid stands as one of the crowning accomplishments of the past century," as Archbishop Desmond Tutu put it, "but we would not have succeeded without the help of international pressure," especially from "the divestment movement of the 1980s."


  The fossil-fuel industry is obviously a tougher opponent, and even if you could force the hand of particular companies, you'd still have to figure out a strategy for dealing with all the sovereign nations that, in effect, act as fossil-fuel companies. But the link for college students is even more obvious in this case. If their college's endowment portfolio has fossil-fuel stock, then their educations are being subsidized by investments that guarantee they won't have much of a planet on which to make use of their degree. (The same logic applies to the world's largest investors, pension funds, which are also theoretically interested in the future – that's when their members will "enjoy their retirement.") "Given the severity of the climate crisis, a comparable demand that our institutions dump stock from companies that are destroying the planet would not only be appropriate but effective," says Bob Massie, a former anti-apartheid activist who helped found the Investor Network on Climate Risk. "The message is simple: We have had enough. We must sever the ties with those who profit from climate change – now."
Movements rarely have predictable outcomes. But any campaign that weakens the fossil-fuel industry's political standing clearly increases the chances of retiring its special breaks. Consider President Obama's signal achievement in the climate fight, the large increase he won in mileage requirements for cars. Scientists, environmentalists and engineers had advocated such policies for decades, but until Detroit came under severe financial pressure, it was politically powerful enough to fend them off. If people come to understand the cold, mathematical truth – that the fossil-fuel industry is systematically undermining the planet's physical systems – it might weaken it enough to matter politically. Exxon and their ilk might drop their opposition to a fee-and-dividend solution; they might even decide to become true energy companies, this time for real.
Even if such a campaign is possible, however, we may have waited too long to start it. To make a real difference – to keep us under a temperature increase of two degrees – you'd need to change carbon pricing in Washington, and then use that victory to leverage similar shifts around the world. At this point, what happens in the U.S. is most important for how it will influence China and India, where emissions are growing fastest. (In early June, researchers concluded that China has probably under-reported its emissions by up to 20 percent.) The three numbers I've described are daunting – they may define an essentially impossible future. But at least they provide intellectual clarity about the greatest challenge humans have ever faced. We know how much we can burn, and we know who's planning to burn more. Climate change operates on a geological scale and time frame, but it's not an impersonal force of nature; the more carefully you do the math, the more thoroughly you realize that this is, at bottom, a moral issue; we have met the enemy and they is Shell.
Meanwhile the tide of numbers continues. The week after the Rio conference limped to its conclusion, Arctic sea ice hit the lowest level ever recorded for that date. Last month, on a single weekend, Tropical Storm Debby dumped more than 20 inches of rain on Florida – the earliest the season's fourth-named cyclone has ever arrived. At the same time, the largest fire in New Mexico history burned on, and the most destructive fire in Colorado's annals claimed 346 homes in Colorado Springs – breaking a record set the week before in Fort Collins. This month, scientists issued a new study concluding that global warming has dramatically increased the likelihood of severe heat and drought – days after a heat wave across the Plains and Midwest broke records that had stood since the Dust Bowl, threatening this year's harvest. You want a big number? In the course of this month, a quadrillion kernels of corn need to pollinate across the grain belt, something they can't do if temperatures remain off the charts. Just like us, our crops are adapted to the Holocene, the 11,000-year period of climatic stability we're now leaving... in the dust.
This story is from the August 2nd, 2012 issue of Rolling Stone.
Related
Bill McKibben: The Arctic Ice CrisisAl Gore: Science and Truth Vs. the Merchants of Poison
Climate Change and the End of Australia

Read more: http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719#ixzz27HNZEO47[/quote]

[/noae]

[scallop]

E, ovu glupost neću da čitam. Svi političari postaju protivnici politika koje su sprovodili, čim više za njih nisu odgovorni.

[Meho Krljic]

Pa, dobro, ovde su u prvom redu naučnici, političari se švercuju!!!!!!!!!!!!1

[scallop]

Naučnici nikada nisu u prvom redu. Da jesu, ne bi ovako bilo.

[Meho Krljic]

Da preformulišem: nećeš da pročitaš dva teksta koje su napisali naučnici (ili su njihovi radovi poslužili kao materijal za tekstove) zato što se sa njima slažu neki političari.

[lilit]

mehane,
ti si ovo stvarno pročitao?

[Meho Krljic]

Skimovao, deluje interesantno, čitaću kad obavim kućne obaveze (usisavanje itd.)

[scallop]

Jok, igraćeš igrice. Čitaš samo uvodne rečenice i naše reakcije. Jebote, naučni članak iz Rollins Stones-a!!!!

[Meho Krljic]

Nebre, pročitao sam ceo prvi članak i skimovao drugi. A zaista usisavam sada. Plus, autor članka iz Roling Stouna nije tek makar tko:

http://en.wikipedia.org/wiki/Bill_McKibben

[Meho Krljic]

Evo, iščitala sam ceo članak u Roling Stounu. Vrlo lepo napisano i sistematično izloženo. Preporuka svima!!!!!11

[lilit]

a da ti to nama lepo dajdžestuješ? u 4 rečenice???!!!

[Meho Krljic]

Da probamo:
Generalni konsenzus (ne BAŠ konsenzus jer neki i dalje odbijaju da prihvate podatke) je da se ne sme dopustiti da prosečna temperatura na Zemlji poraste za više od dva stepena - izuzetno liberalna granica jer i sa postojećim porastom od 0,8 stepeni vidimo užasne promene, ali ova je granica rezultat kompromisa između nauke, politike i industrije. Ova granica će biti dostignuta kada se u atmosferu oslobodi još oko 565 gigatona ugljen-dioksida (tzv. ugljenični budžet). Trenutno poznate rezerve fosilnih goriva na koje neko (države i firme) polaže pravo imaju potencijal da oslobode oko 2500 gigatona, dakle pet puta više od "dopuštenog"ugljeničnog budžeta. Dakle, promeniti i preokrenuti trend koji nas vodi u toplotnu kataklizmu znači naterati industriju vrednu trilione dolara (jer na osnovu ovih rezervi firme i države formiraju svoju vrednost na berzi, dobijaju kredite i investicije) da se odrekne četiri petine svoje vrednosti, što lobiranjem na obične korisnike/ građane do sada nije uspelo i samo je za nijansu bilo manje neuspešno lobirajući političare. (Peta bonus rečenica) Moguće rešenje se vidi u nečemu sličnom što je rađeno osamdesetih sa Aparthejdom, kada su univerziteti i druge institucije prekidale da sarađuju sa firmama koje su poslovale sa režimom u JAR, jer se u njima vidi neka vrsta inteligencije sklone aktivizmu, sa dovoljno širokom mrežom da zapravo ima nekog uticaja itd.

Od mene toliko!!!!!!!!!!!!

[scallop]

Baš si se napeo. Lilit i ja smo sad pametniji za nekoliko gigatona.

[Meho Krljic]

Sve za Sagitu, Sagitu nizašta.

[lilit]

fala mehane, srce si ko i uvek.

[mac]

Prilično temeljit članak o otapanju leda. Ima obilje podataka, grafika, i vrlo je ozbiljan i profesionalan. Scallopu će se svideti. Jedini problem je što je tekst dug 15 stranica.

http://io9.com/5945658/what-the-hell-is-happening-to-the-arctic-sea-ice

[scallop]

Jel' paralelno daju podatke koliko je zbog otapanja do sada podignut nivo okeana i mora? Ne može led da se spusti, a da se ne digne.

[mac]

I to je objašnjeno. Led koji pluta na vodi neće podići nivo vode kad se otopi. Led koji je na tlu (Grenland i Antarktik) bi podigao nivo vode, ali taj led nije problem, jer se jako teško topi.

[scallop]

To za plutanje se podrazumeva. Verujemo Arhimedu. Kako ide sa ledom koji se jako teško topi? Mac, ja se malo šalim, ali sam u biti vrlo ozbiljan. Znam kako ide sa otapanjem, ali kao i sve drugo, pomalo preuveličavamo. A, narod jeste naučio da čita, ali sa razumevanjem ide malo teže. Recimo, dokumentovano je otopljavanje u poslednjig tridesetak godina, ali bih voleo i podatak da li je u istorijsko vreme, ovo pa skoro naše, bilo isto toliko dugih ili dužih perioda zahlađenja. Može se dogoditi da ih je bilo, zar ne? I zbog prirodnijih uzroka nego što je doprinos čoveka. Jebiga, kad uporedim milijardu bizona koje smo potamanili i zamenili ih kravama, može li se dogoditi da su u masi jednako prdeli CO²?

[mac]

U 15 strana teksta nisu spominjani bizoni, ali metan i permafrost jesu. Spominju se i projektovani podaci pre početka merenja. Za deceniju probićemo i rekorde iz praistorije.

[scallop]

Onda, dobro. Ja sam za vedriju raspravu. Super ozbiljne stvari ostavio bih super ozbiljnim ljudima.

[mac]

Ne valja ozbiljno, ne valja neozbiljno. Kamo sad?

[scallop]

I super neozbiljne stvari bih ostavio super neozbiljnim ljudima.

[Meho Krljic]

Još malo mračnih predviđanja:

Climate change evident across Europe, says report

By Mark Kinver Environment reporter, BBC News
  The effects of climate change are already evident in Europe and the situation is set to get worse, the European Environment Agency has warned.
In a report, the agency says the past decade in Europe has been the warmest on record.
It adds that the cost of damage caused by extreme weather events is rising, and the continent is set to become more vulnerable in the future.
The findings have been published ahead of next week's UN climate conference.
They join a UN Environment Programme report also released on Wednesday showing dangerous growth in the "emissions gap" - the difference between current carbon emission levels and those needed to avert climate change.
"Every indicator we have in terms of giving us an early warning of climate change and increasing vulnerability is giving us a very strong signal," observed EEA executive director Jacqueline McGlade.
"It is across the board, it is not just global temperatures," she told BBC News.
"It is in human health aspects, in forests, sea levels, agriculture, biodiversity - the signals are coming in from right across the environment."
2C or not 2C
The report - Climate Change, Impacts and Vulnerabilities in Europe 2012 - involving more than 50 authors from a range of organisations, listed a number of "key messages", including:
 

   
• Observed climate change has "already led to a wide range of impacts on environmental systems and society; further climate change impacts are projected for the future";
• Climate change can increase existing vulnerabilities and deepen socio-economic imbalances in Europe;
• The combined impacts of projected climate change and socio-economic development is set to see the damage costs of extreme weather events continue to increase.

As it currently stands, the UN Framework Convention on Climate Change has set a target of limiting the rise in global mean temperature to 2C (3.6F) above pre-industrial levels.
But the report's authors warn that even if this target to mitigate warming is met, "substantial impacts on society, human health and ecosystems are projected to occur".
To limit the impacts, experts say effective adaptation strategies need to be developed in order to minimise the risk to nations' infrastructure, homes and businesses.
The European Commission is expected to publish its European Adaptation Strategy in 2013, outlining measures it think will help the 27-nation bloc deal with future climate shifts.

Examples of adaptation measures include using water resources more efficiently, adapting building codes to be able to withstand extreme weather events and building flood defences.
Prof McGlade said such measures would be essential in order to climate-proof the EU.

"I think what the European Commission and other parts of the world are finding is that whilst it is important to understand what is happening at the global level, it is what is happening at the regional and local levels that will really determine how economies will weather the storm," she said.
The report said the cost of damage caused by extreme weather events had increased from 9bn euros (£7bn) in the 1980s to 13bn euros in the 2000s.
One of the report's authors, Andre Jol, head of the EEA's vulnerability and adaptation group, added: "We know that the main increase in damage costs from natural disasters has not been from climate change, as such, but more as a result of an increase in wealth, people and infrastructure in risk areas.
"But one of the key messages from the report is that in the future, with projected increases in the frequency and intensity of extreme events, we know that climate change will contribute to the increase in the cost of damage from extreme events."
'Lack of action'
On Monday, the World Bank published a report that warned that the world was "on track to a 4C [increase by the end of the century] marked by extreme heatwaves and life-threatening sea-level rise".
It added that the world's poorest regions would be hardest hit by the warming, which was "likely to undermine efforts and goals".
"A 4C warmer world can, and must be, avoided - we need to hold warming below 2C," said World Bank group president Jim Yong Kim.
"Lack of action on climate change threatens to make the world our children inherit a completely different world than we are living in today."
However, the UN Environment Programme (Unep) warned that it was still possible to achieve the 2C target but time was running out.
Data in the Emissions Gap Report showed that annual greenhouse gas emissions were now "14% above where they need to be in 2020".
Unep executive director Achim Steiner said: "While governments work to negotiate a new international climate agreement to come into effect in 2020, they urgently need to put their foot firmly on the action pedal by fulfilling financial, technology transfer and other commitments under the UN climate convention treaties."
The reports have been published ahead of the annual two-week UN climate conference, which starts on Monday in Doha, Qatar.

A evo i izveštaja koji se pominje u celini (mada ima i link u tekstu):

http://www.eea.europa.eu/publications/climate-impacts-and-vulnerability-2012

[Barbarin]

Kad je zadnji put u novembru bilo ovako toplo?

Vode je palo ove godine, čini mi se, jako malo.

Postaćemo pustinja 

[Truba]

najfascinantnije mi je to što lišće ne pada u listopadu nego ga još ima na drveću i za vrijeme ovoga mjeseca...
a na nekim još nije ni krenulo žutiti

[Meho Krljic]

Pa, da.

A pošto dosta ljudi i dalje tvrdi da su klimacke promene farsa, da nisu efekat industrije, te da mnogi naučnici sumnjaju u sve to, evo jednog zanimljivog teksta od pre par meseci. Autor je profesor sa Berklija, što ne znači da u teoriji ne može da bude šil. Ali evo:

The Conversion of a Climate-Change Skeptic

By RICHARD A. MULLER Published: July 28, 2012          Berkeley, Calif.


CALL me a converted skeptic. Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I'm now going a step further: Humans are almost entirely the cause.
My total turnaround, in such a short time, is the result of careful and objective analysis by the Berkeley Earth Surface Temperature project, which I founded with my daughter Elizabeth. Our results show that the average temperature of the earth's land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.
These findings are stronger than those of the Intergovernmental Panel on Climate Change, the United Nations group that defines the scientific and diplomatic consensus on global warming. In its 2007 report, the I.P.C.C. concluded only that most of the warming of the prior 50 years could be attributed to humans. It was possible, according to the I.P.C.C. consensus statement, that the warming before 1956 could be because of changes in solar activity, and that even a substantial part of the more recent warming could be natural.
Our Berkeley Earth approach used sophisticated statistical methods developed largely by our lead scientist, Robert Rohde, which allowed us to determine earth land temperature much further back in time. We carefully studied issues raised by skeptics: biases from urban heating (we duplicated our results using rural data alone), from data selection (prior groups selected fewer than 20 percent of the available temperature stations; we used virtually 100 percent), from poor station quality (we separately analyzed good stations and poor ones) and from human intervention and data adjustment (our work is completely automated and hands-off). In our papers we demonstrate that none of these potentially troublesome effects unduly biased our conclusions.
The historic temperature pattern we observed has abrupt dips that match the emissions of known explosive volcanic eruptions; the particulates from such events reflect sunlight, make for beautiful sunsets and cool the earth's surface for a few years. There are small, rapid variations attributable to El Niño and other ocean currents such as the Gulf Stream; because of such oscillations, the "flattening" of the recent temperature rise that some people claim is not, in our view, statistically significant. What has caused the gradual but systematic rise of two and a half degrees? We tried fitting the shape to simple math functions (exponentials, polynomials), to solar activity and even to rising functions like world population. By far the best match was to the record of atmospheric carbon dioxide, measured from atmospheric samples and air trapped in polar ice.
Just as important, our record is long enough that we could search for the fingerprint of solar variability, based on the historical record of sunspots. That fingerprint is absent. Although the I.P.C.C. allowed for the possibility that variations in sunlight could have ended the "Little Ice Age," a period of cooling from the 14th century to about 1850, our data argues strongly that the temperature rise of the past 250 years cannot be attributed to solar changes. This conclusion is, in retrospect, not too surprising; we've learned from satellite measurements that solar activity changes the brightness of the sun very little.
How definite is the attribution to humans? The carbon dioxide curve gives a better match than anything else we've tried. Its magnitude is consistent with the calculated greenhouse effect — extra warming from trapped heat radiation. These facts don't prove causality and they shouldn't end skepticism, but they raise the bar: to be considered seriously, an alternative explanation must match the data at least as well as carbon dioxide does. Adding methane, a second greenhouse gas, to our analysis doesn't change the results. Moreover, our analysis does not depend on large, complex global climate models, the huge computer programs that are notorious for their hidden assumptions and adjustable parameters. Our result is based simply on the close agreement between the shape of the observed temperature rise and the known greenhouse gas increase.
It's a scientist's duty to be properly skeptical. I still find that much, if not most, of what is attributed to climate change is speculative, exaggerated or just plain wrong. I've analyzed some of the most alarmist claims, and my skepticism about them hasn't changed.
Hurricane Katrina cannot be attributed to global warming. The number of hurricanes hitting the United States has been going down, not up; likewise for intense tornadoes. Polar bears aren't dying from receding ice, and the Himalayan glaciers aren't going to melt by 2035. And it's possible that we are currently no warmer than we were a thousand years ago, during the "Medieval Warm Period" or "Medieval Optimum," an interval of warm conditions known from historical records and indirect evidence like tree rings. And the recent warm spell in the United States happens to be more than offset by cooling elsewhere in the world, so its link to "global" warming is weaker than tenuous.
The careful analysis by our team is laid out in five scientific papers now online at BerkeleyEarth.org. That site also shows our chart of temperature from 1753 to the present, with its clear fingerprint of volcanoes and carbon dioxide, but containing no component that matches solar activity. Four of our papers have undergone extensive scrutiny by the scientific community, and the newest, a paper with the analysis of the human component, is now posted, along with the data and computer programs used. Such transparency is the heart of the scientific method; if you find our conclusions implausible, tell us of any errors of data or analysis.
What about the future? As carbon dioxide emissions increase, the temperature should continue to rise. I expect the rate of warming to proceed at a steady pace, about one and a half degrees over land in the next 50 years, less if the oceans are included. But if China continues its rapid economic growth (it has averaged 10 percent per year over the last 20 years) and its vast use of coal (it typically adds one new gigawatt per month), then that same warming could take place in less than 20 years.
Science is that narrow realm of knowledge that, in principle, is universally accepted. I embarked on this analysis to answer questions that, to my mind, had not been answered. I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes. Then comes the difficult part: agreeing across the political and diplomatic spectrum about what can and should be done.
   

Richard A. Muller, a professor of physics at the University of California, Berkeley, and a former MacArthur Foundation fellow, is the author, most recently, of "Energy for Future Presidents: The Science Behind the Headlines." 

[Mica Milovanovic]

Ja mislim da bih mogao da se nađem u istoj korpi sa dotičnim.


Iako kao svaki Srbin imam veliko podozrenje prema izveštajima dotične institucije,
ovaj dokument je verovatno najaktuelniji summary znanja o CC.


Verovali ili ne u CC, nije loše da se pročita...


http://climatechange.worldbank.org/sites/default/files/Turn_Down_the_heat_Why_a_4_degree_centrigrade_warmer_world_must_be_avoided.pdf


Bojim se da se ne nađemo u situaciji u kojoj je bio onaj što je stalno vikao: "Vuk... vuk..."

[mac]

Ima razlike između priče i naše situacije. U priči kad dečak na početku viče celo selo mu dođe. Kod nas naučnici viču, a političari nikad ništa.

[scallop]

Mićo, sve dok ne pomene Kinu meni je uverljivo. Kad pomene Kinu, ja se setim ko je za sve kriv.

[Truba]

nevjerovatno
otkud onaj autobus žute boje linija dom armije podhrastovi na naslovnici tog izvještaja
oćete reći da je gradski prevoz sarajeva veliki zagađivač 

[Mica Milovanovic]

U Sarajevu pocnu sva svetska sranja...

[Meho Krljic]

Evo, nije samo Kina kriva:

Coal resurgence calls undermine clean energy commitments

Coal, the dirtiest and most polluting of all the major fossil fuels, is making a comeback.
Despite stringent carbon emissions targets in Europe designed to slow global warming and massive investment in renewable energy in China, demand for this most ancient source of energy is greater than ever.
In fact, coal was the fastest growing form of energy in the world outside renewables last year, with production up 6% on 2010, twice the rate of increase of gas and more than four times that of oil. Consumption data paints a similar picture, while figures for this year are set to tell the same story.
There are a number of drivers behind coal's renaissance, many of which may be short lived. Others will push demand ever higher for decades to come.
Cheap alternative
Coal consumption in Europe, where governments have been at the forefront of the push to curb carbon dioxide emissions, has risen sharply in recent years.

Why? Because it's cheap, and getting cheaper all the time. Due to the economic downturn, there has been what Paul McConnell, senior analyst at energy research group Wood Mackenzie, calls a "collapse in industrial demand for energy". This has led to an oversupply of coal, pushing the price down.
It has also led to a massive surfeit of CO2 emissions permits, pushing the price of carbon, and therefore the cost of coal production, sharply lower.
Equally important, there has been a huge influx of cheap coal from the US, where the discovery of shale gas has provided an even cheaper alternative energy source. The coal has to go somewhere, so it's exported to Europe.
Finally, higher non-shale, natural gas prices are making coal an attractive alternative.
As Laszlo Varro, head of gas, coal and power markets at the International Energy Agency (IEA), says: "All parameters favour coal."
So much so that "coal is [now] being burned as the baseload fuel across most of Europe," says Gareth Carpenter, associate editor at global energy information provider Platts.
Germany's decision to scrap all nuclear power and build more coal-fired power stations can only boost production further.
Just how long coal's resurgence lasts depends to some extent on the global economic recovery and the ability of governments to implement a system that finally delivers a meaningful carbon price.

But, in the meantime, legislation passed more than a decade ago will severely curb coal production over the coming years, according to Mr Varro.
The full impact of the EU's Large Combustion Plant Directive, which is designed to reduce local air pollutants, but not in fact carbon dioxide, is about to be felt, meaning a number of inefficient coal plants will be decommissioned.
As a result, in five years, coal production capacity "will be considerably lower than today", says Mr Varro. The directive will do nothing, of course, to restrict cheap US imports.
Demand explosion
But whatever happens to coal production and consumption in Europe, spiralling demand for energy in Asia, in particular China, will ensure that coal production continues to rise significantly over the coming decades.

Population growth and the exploding middle classes will see to that - in China alone, demand for energy will triple by 2030, according to Wood Mackenzie.
China in particular is spending massive amounts of money on a renewable energy drive the likes of which the world has never seen - plans are in place to build almost 10 times the wind capacity of Germany, for example.
But even this will not be able to keep up with demand, meaning fossil fuels will continue to make up the majority of the overall energy mix for the foreseeable future.
And when it comes to fossil fuels, coal is the easy winner - it is generally easier and cheaper to mine, and easier to transport using existing infrastructure such as roads and rail, than oil or gas.

Its price is also relatively stable because, as Mr Carpenter points out: "Coal mines on the whole are located in relatively stable countries free from major geopolitical tensions."
For all these reasons, Wood Mackenzie forecasts coal production in Indonesia, currently the world's fourth-biggest coal producer, to rise by 60% by 2020, while China will import more than a billion tonnes by 2030, almost five times currents levels.
By this date, it expects global demand for imported coal to more than double, helping to push the fossil fuel's proportion of the overall energy mix even higher than it is today.
Carbon capture
Cheap energy is, of course, a vital ingredient in the continued economic growth of developing countries, but the implications of rising coal production for CO2 emissions and global warming are profound.
While China is currently running half a dozen carbon capture and storage (CCS) projects - which aim to capture CO2 emissions from coal plants and bury it underground - the technology is nowhere near commercial viability.

As Mr Carpenter says, despite all the hype "it looks extremely unlikely that CCS technology is going to be deployed widely in the next 10 years or so".
The inevitable end result is rising CO2 emissions. According to the IEA, emissions from fossil fuels hit a record level last year, while total energy-related emissions and are due to rise by more than 20% by 2035.
"Why we aren't developing CCS for all we're worth is a mystery to me," says Prof Myles Allen at the school of geography and the environment at the University of Oxford.
"It is viewed as just one of a basket of solutions, but it's not - it's pivotal. Without it, nothing else follows."
And CCS lends itself perfectly to coal, precisely because it is such a cheap energy source.
Renewed urgency in developing CCS globally, alongside greater strides in increasing renewable energy capacity, is desperately needed, but Europe's increasing reliance on coal without capturing emissions is undermining its status as a leader in clean energy, and therefore global efforts to reduce CO2 emissions.





Coal hard facts

   
• Coal is responsible for about 40% of the world's carbon dioxide emissions from fuels
• Coal generates almost a half of the total amount of electricity produced in the US
• Coal emits almost a third more carbon dioxide per unit of energy than oil, and 70% more than natural gas
• Coal provides about a quarter of the world's energy needs and it generates almost 40% of the world's electricity
• Almost 70% of total global steel production is also dependent on burning coal.

[Meho Krljic]

Grim picture of polar ice-sheet loss

Antarctica and Greenland are rapidly losing their ice sheets because of climate change, says a comprehensive review.

Olive Heffernan
29 November 2012   A global team of researchers has come up with the 'most accurate estimate' yet for melting of the polar ice sheets, ending decades of uncertainty about whether the sheets will melt further or actually gain mass in the face of climate change. The ice sheets in Greenland and Antarctica are melting at an ever-quickening pace. Since 1992, they have contributed 11 millimetres — or one-fifth — of the total global sea-level rise, say researchers. The two polar regions are now losing mass three times faster than they were 20 years ago, with Greenland alone now shedding ice at about five times the rate observed in the early 1990s.
This latest estimate¹, published this week in Science, draws on up to 32 years of ice-sheet simulations and 20 years of satellite data.


With climate change, some scientists had expected that warmer air would increase snowfall over Antarctica, and that this would largely offset the increased ice loss from Greenland caused by warmer seas. In recent years, however, a number of studies have shown^2–4 that both ice sheets are losing mass at an alarming rate, as ice streams speed up their seaward journeys and more and bigger icebergs are discharged into the ocean.
Estimates have not always been consistent with each other, however⁵, leaving scientists concerned about their reliability. In its 2007 report, the Intergovernmental Panel on Climate Change (IPCC) declined to set an upper limit on the extent to which ice loss from Antarctica could contribute to sea-level rise, saying the science was too uncertain⁶.
The latest study "moves Antarctica from a position of relative uncertainty in terms of its ice loss to one where we are now certain that it is losing ice", says Andrew Shepherd, first author of the study and professor of Earth observation at the University of Leeds, UK.
Scientists use four techniques to gauge whether the ice caps are gaining or losing mass. Two techniques involve using either lasers or radars on satellites to measure changes in the surface elevation of the ice; another uses a method known as input-output modelling to represent regional changes in snowfall and ice melt; and the fourth measures changes in ice-sheet mass from space using the Gravity Recovery and Climate Experiment (GRACE) mission satellites.
Compensatory snowfall The international team of 47 experts led by Shepherd analysed data collected by these methods from almost 30 previous ice-sheet studies, including 20 years of data from 10 different satellite missions and 32 years of model data on surface mass balance — the difference in the weight of the ice sheet gained through snowfall and lost through melting of the ice sheets.
The result is an estimate "two to three times more accurate than that in the last IPCC report", says Shepherd.
Riccardo Riva, a geoscientist at Delft University of Technology in the Netherlands, independent of the study, says: "It provides a solid answer to the whole scientific community and the general public that over the last 20 years, the polar ice sheets did contribute to global mean sea-level rise by a significant amount."
Yet large uncertainties remain, especially for Antarctica. The good news, says Riva, is that Antarctica is not losing ice as rapidly as suggested by many recent studies. What's more, snowfall in east Antarctica still seems to be compensating for some — but not all — of the melting elsewhere in Antarctica.
It is unclear how these trends, such as ice loss from Greenland, will evolve, says Ian Joughin, one of the paper's co-authors and a satellite expert at the University of Washington in Seattle. "It really remains unclear whether such losses will decline, whether they'll level off or they'll accelerate further," he says.
  Journal name: Nature DOI: doi:10.1038/nature.2012.11921

[Meho Krljic]

Norveška studija tvrdi da globalno zagrevanje nije tako strašno. Američki komentator ističe da je ovo studija koja još nije doživela pir rivju pa je treba uzeti s malo soli.

http://www.forskningsradet.no/en/Newsarticle/Global_warming_less_extreme_than_feared/1253983344535/p1177315753918?WT.ac=forside_nyhet

Global warming less extreme than feared? Policymakers are attempting to contain global warming at less than 2°C. New estimates from a Norwegian project on climate calculations indicate this target may be more attainable than many experts have feared.
  Internationally renowned climate researcher Caroline Leck of Stockholm University has evaluated the Norwegian project and is enthusiastic.
"These results are truly sensational," says Dr Leck. "If confirmed by other studies, this could have far-reaching impacts on efforts to achieve the political targets for climate."
Temperature rise is levelling off After Earth's mean surface temperature climbed sharply through the 1990s, the increase has levelled off nearly completely at its 2000 level. Ocean warming also appears to have stabilised somewhat, despite the fact that CO2 emissions and other anthropogenic factors thought to contribute to global warming are still on the rise.
It is the focus on this post-2000 trend that sets the Norwegian researchers' calculations on global warming apart.
Sensitive to greenhouse gases Climate sensitivity is a measure of how much the global mean temperature is expected to rise if we continue increasing our emissions of greenhouse gases into the atmosphere.
CO2 is the primary greenhouse gas emitted by human activity. A simple way to measure climate sensitivity is to calculate how much the mean air temperature will rise if we were to double the level of overall CO2 emissions compared to the world's pre-industrialised level around the year 1750.
If we continue to emit greenhouse gases at our current rate, we risk doubling that atmospheric CO2 level in roughly 2050.

Mutual influences A number of factors affect the formation of climate development. The complexity of the climate system is further compounded by a phenomenon known as feedback mechanisms, i.e. how factors such as clouds, evaporation, snow and ice mutually affect one another.
Uncertainties about the overall results of feedback mechanisms make it very difficult to predict just how much of the rise in Earth's mean surface temperature is due to manmade emissions. According to the Intergovernmental Panel on Climate Change (IPCC) the climate sensitivity to doubled atmospheric CO2 levels is probably between 2°C and 4.5°C, with the most probable being 3°C of warming.
In the Norwegian project, however, researchers have arrived at an estimate of 1.9°C as the most likely level of warming.
Manmade climate forcing "In our project we have worked on finding out the overall effect of all known feedback mechanisms," says project manager Terje Berntsen, who is a professor at the University of Oslo's Department of Geosciences and a senior research fellow at the Center for International Climate and Environmental Research – Oslo (CICERO). The project has received funding from the Research Council of Norway's Large-scale Programme on Climate Change and its Impacts in Norway (NORKLIMA).
"We used a method that enables us to view the entire earth as one giant 'laboratory' where humankind has been conducting a collective experiment through our emissions of greenhouse gases and particulates, deforestation, and other activities that affect climate."
For their analysis, Professor Berntsen and his colleagues entered all the factors contributing to human-induced climate forcings since 1750 into their model. In addition, they entered fluctuations in climate caused by natural factors such as volcanic eruptions and solar activity. They also entered measurements of temperatures taken in the air, on ground, and in the oceans.
The researchers used a single climate model that repeated calculations millions of times in order to form a basis for statistical analysis. Highly advanced calculations based on Bayesian statistics were carried out by statisticians at the Norwegian Computing Center.
2000 figures make the difference When the researchers at CICERO and the Norwegian Computing Center applied their model and statistics to analyse temperature readings from the air and ocean for the period ending in 2000, they found that climate sensitivity to a doubling of atmospheric CO2 concentration will most likely be 3.7°C, which is somewhat higher than the IPCC prognosis.
But the researchers were surprised when they entered temperatures and other data from the decade 2000-2010 into the model; climate sensitivity was greatly reduced to a "mere" 1.9°C.
Professor Berntsen says this temperature increase will first be upon us only after we reach the doubled level of CO2 concentration (compared to 1750) and maintain that level for an extended time, because the oceans delay the effect by several decades.


Natural changes also a major factor
The figure of 1.9°C as a prediction of global warming from a doubling of atmospheric CO2 concentration is an average. When researchers instead calculate a probability interval of what will occur, including observations and data up to 2010, they determine with 90% probability that global warming from a doubling of CO2 concentration would lie between 1.2°C and 2.9°C.
This maximum of 2.9°C global warming is substantially lower than many previous calculations have estimated. Thus, when the researchers factor in the observations of temperature trends from 2000 to 2010, they significantly reduce the probability of our experiencing the most dramatic climate change forecast up to now.
Professor Berntsen explains the changed predictions:
"The Earth's mean temperature rose sharply during the 1990s. This may have caused us to overestimate climate sensitivity.
"We are most likely witnessing natural fluctuations in the climate system – changes that can occur over several decades – and which are coming on top of a long-term warming. The natural changes resulted in a rapid global temperature rise in the 1990s, whereas the natural variations between 2000 and 2010 may have resulted in the levelling off we are observing now."
Climate issues must be dealt with Terje Berntsen emphasises that his project's findings must not be construed as an excuse for complacency in addressing human-induced global warming. The results do indicate, however, that it may be more within our reach to achieve global climate targets than previously thought.
Regardless, the fight cannot be won without implementing substantial climate measures within the next few years.
Sulphate particulates The project's researchers may have shed new light on another factor: the effects of sulphur-containing atmospheric particulates.

Burning coal is the main way that humans continue to add to the vast amounts of tiny sulphate particulates in the atmosphere. These particulates can act as condensation nuclei for cloud formation, cooling the climate indirectly by causing more cloud cover, scientists believe. According to this reasoning, if Europe, the US and potentially China reduce their particulate emissions in the coming years as planned, it should actually contribute to more global warming.
But the findings of the Norwegian project indicate that particulate emissions probably have less of an impact on climate through indirect cooling effects than previously thought.
So the good news is that even if we do manage to cut emissions of sulphate particulates in the coming years, global warming will probably be less extreme than feared.

About the project

Geophysicists at the research institute CICERO collaborated with statisticians at the Norwegian Computing Center on a novel approach to global climate calculations in the project "Constraining total feedback in the climate system by observations and models". The project received funding from the Research Council of Norway's NORKLIMA programme. The researchers succeeded in reducing uncertainty around the climatic effects of feedback mechanisms, and their findings indicate a lowered estimate of probable global temperature increase as a result of human-induced emissions of greenhouse gases. The project researchers were able to carry out their calculations thanks to the free use of the high-performance computing facility in Oslo under the Norwegian Metacenter for Computational Science (Notur). The research project is a prime example of how collaboration across subject fields can generate surprising new findings.

  Written by:  Bård Amundsen/Else Lie. Translation: Darren McKellep/Carol B. Eckmann  Published:  24.01.2013  Last updated:  25.01.2013

http://dotearth.blogs.nytimes.com/2013/01/26/weaker-global-warming-seen-in-study-promoted-by-norways-research-council/

[mac]

Pa da, Norvežanima zagrevanje dođe kao kec na deset.

[mac]

Otvorena je peticija za sve žitelje planete Zemlje. Upućena je generalnom sekretaru Ujedinjenih Nacija. Trajanje peticije je godinu i mesec dana. Cilj peticije: milijarda potpisa. Upišite se dok još možete da zapamtite svoj redni broj

http://yourclimatechange.org/

[Meho Krljic]

Naravno, ima još pametnjakovića koji će na pominjanje globalnog zagrevanja ukazivati kako je ovo proljeće u stvari vlažno i hladno. Nauka (ili barem neki naučnici koji rade u Nacionalnom Centru za podatke o snijegu i ledu u Koloradu, SAD i drugim SAD institucijama) veli da to ima rezona:

Scientists Link Cold Spring to Dramatic Sea Ice Loss

Climate scientists have linked the massive snowstorms and bitter spring weather now being experienced across Britain and large parts of Europe and North America to the dramatic loss of Arctic sea ice.
Both the extent and the volume of the sea ice that forms and melts each year in the Arctic Ocean fell to an historic low last autumn, and satellite records published on Monday by the National Snow and Ice Data Centre (NSIDC) in Boulder, Colorado, show the ice extent is close to the minimum recorded for this time of year.
"The sea ice is going rapidly. It's 80 percent less than it was just 30 years ago. There has been a dramatic loss. This is a symptom of global warming and it contributes to enhanced warming of the Arctic," said Jennifer Francis, research professor with the Rutgers Institute of Coastal and Marine Science.
(MORE: Why Arctic Sea Ice Melts So Quickly) According to Francis and a growing body of other researchers, the Arctic ice loss adds heat to the ocean and atmosphere which shifts the position of the jet stream – the high-altitude river of air that steers storm systems and governs most weather in northern hemisphere.
"This is what is affecting the jet stream and leading to the extreme weather we are seeing in mid-latitudes," she said. "It allows the cold air from the Arctic to plunge much further south. The pattern can be slow to change because the [southern] wave of the jet stream is getting bigger. It's now at a near record position, so whatever weather you have now is going to stick around," she said.
Francis linked the Arctic temperature rises to extreme weather in mid latitudes last year and warned in September that 2012's record sea ice melt could lead to a cold winter in the UK and northern Europe.
She was backed by Vladimir Petoukhov, professor of Earth system analysis at Potsdam Institute in Germany, whose research suggests the loss of ice this year could be changing the direction of the jet stream.
"The ice was at a record low last year and is now exceptionally low in some parts of the Arctic like the Labrador and Greenland seas. This could be one reason why anticyclones are developing," he said.
(PHOTOS: Record Lows for Spring Break?)
The heavy snowfall and freezing temperatures which have marked March 2013 across the northern hemisphere are in stark contrast to March 2012 when many countries experienced their warmest ever springs. The hypothesis that wind patterns are being changed because melting Arctic sea ice has exposed huge swaths of normally frozen ocean to the atmosphere would explain both the extremes of heat and cold, say the scientists.
A recent paper by the US government's National Oceanic and Atmospheric Administration (NOAA) also found that enhanced warming of the Arctic influenced weather across the northern hemisphere.

"With more solar energy going into the Arctic Ocean because of lost ice, there is reason to expect more extreme weather events, such as heavy snowfall, heat waves, and flooding in North America and Europe," said the researchers.
The Met Office's chief scientist has previously said the melting Arctic ice is in part responsible for the UK's recent colder winters.
The possible links between Arctic sea ice loss and extreme weather were made as the UK's government's outgoing chief scientific adviser Sir John Beddington warned that the world could expect more extremes of weather.
"The [current] variation we are seeing in temperature or rainfall is double the rate of the average. That suggests that we are going to have more droughts, we are going to have more floods, we are going to have more sea surges and we are going to have more storms." He said that said there was a "need for urgency" in tackling climate change.
"These are the sort of changes that are going to affect us in quite a short timescale," he warned. Last year saw record heat, rainfall, drought and floods in the northern hemisphere.

[Mouchette]

The Earth could be closer than previously thought to the inner edge of the Sun's habitable zone, according to a new study by planetary scientists in the US and France. The research also suggests that if our planet moved out of the habitable zone, it could lead to a "moist greenhouse" climate that could kick-start further drastic changes to the atmosphere...

Earth is closer to the edge of Sun's habitable zone

[Meho Krljic]

Arctic nearly free of summer sea ice during first half of 21st century

For scientists studying summer sea ice in the Arctic, it's not a question of "if" there will be nearly ice-free summers, but "when." And two scientists say that "when" is sooner than many thought — before 2050 and possibly within the next decade or two.

James Overland of NOAA's Pacific Marine Environmental Laboratory and Muyin Wang of the NOAA Joint Institute for the Study of Atmosphere and Ocean at the University of Washington, looked at three methods of predicting when the Arctic will be nearly ice free in the summer. The work was published recently online in the American Geophysical Union publication Geophysical Research Letters.

"Rapid Arctic sea ice loss is probably the most visible indicator of global climate change; it leads to shifts in ecosystems and economic access, and potentially impacts weather throughout the northern hemisphere," said Overland. "Increased physical understanding of rapid Arctic climate shifts and improved models are needed that give a more detailed picture and timing of what to expect so we can better prepare and adapt to such changes. Early loss of Arctic sea ice gives immediacy to the issue of climate change."
"There is no one perfect way to predict summer sea ice loss in the Arctic," said Wang. "So we looked at three approaches that result in widely different dates, but all three suggest nearly sea ice-free summers in the Arctic before the middle of this century."

Overland and Wang emphasized that the term "nearly" ice free is important as some sea ice is expected to remain north of the Canadian Archipelago and Greenland.

   
• The "trendsetters" approach uses observed sea ice trends. These data show that the total amount of sea ice decreased rapidly over the previous decade. Using those trends, this approach extrapolates to a nearly sea ice-free Arctic by 2020.
  
  
• The "stochasters" approach is based on assuming future multiple, but random in time, large sea ice loss events such as those that occurred in 2007 and 2012. This method estimates it would take several more events to reach a nearly sea ice-free state in the summer. Using the likelihood of such events, this approach suggests a nearly sea ice-free Arctic by about 2030 but with large uncertainty in timing.
• 
  The "modelers" approach is based on using the large collection of global climate model results to predict atmosphere, ocean, land, and sea ice conditions over time. These models show the earliest possible loss of sea ice to be around 2040 as greenhouse gas concentrations increase and the Arctic warms. But the median timing of sea ice loss in these models is closer to 2060. There are several reasons to consider that this median timing of sea ice loss in these models may be too slow.

"Some people may interpret this to mean that models are not useful. Quite the opposite," said Overland. "Models are based on chemical and physical climate processes and we need better models for the Arctic as the importance of that region continues to grow."
Taken together, the range among the multiple approaches still suggests that it is very likely that the timing for future sea ice loss will be within the first half of the 21st century, with a possibility of major loss within a decade or two.
NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources.

[Meho Krljic]

Evo, za skeptike koji i dalje ne veruju da 1) su globalno zagrevanje/ klimatske promene stvaran trend i 2) je u pitanju antropogen fenomen, napravljen je sledeći projekat:

The Consensus Project

Ovo je jedna sređena metastudija koja uzima rezultate više studija, poredi ih, i pokušava da ponudi najobjektivniju zamislivu sliku.

[scallop]

Studije globalnog zagrevanja su svakako neophodne, jer smo valjda sazreli da se i time petljamo. Međutim, zaključci se i dalje donose na osnovu suviše kratkih vremenskih perioda. Univerzum se i dalje pita šta je to 30-50 godina u odnosu na milijarde godina. Mnogim naučnicima se žuri da budu u pravu, ali njihov procenat je mizeran u odnosu na mogućnosti. Ne bi znali da daju ni pouzdan odgovor na pitanje zašto je presušila Sarsavati, zbog globalnog zagrevanja ili prostog pomeranja Himalaja. Ako ne znaju oni koji znaju, kako da razumemo mi koji ne znamo?

[mac]

Dobar je ovaj sajt. Sviđa mi se.