Radical plan proposed to re-freeze the Arctic

Physicist Steven Desch has come up with a novel solution to the problems that now beset the Arctic. He and a team of colleagues from Arizona State University want to replenish the region’s shrinking sea ice – by building 10 million wind-powered pumps over the Arctic ice cap. In winter, these would be used to pump water to the surface of the ice where it would freeze, thickening the cap.

The pumps could add an extra metre of sea ice to the Arctic’s current layer, Desch argues. The current cap rarely exceeds 2-3 metres in thickness and is being eroded constantly as the planet succumbs to climate change.

“Thicker ice would mean longer-lasting ice. In turn, that would mean the danger of all sea ice disappearing from the Arctic in summer would be reduced significantly,” Desch told the Observer.

Desch and his team have put forward the scheme in a paper that has just been published in Earth’s Future, the journal of the American Geophysical Union, and have worked out a price tag for the project: $500bn (£400bn).

It is an astonishing sum. However, it is the kind of outlay that may become necessary if we want to halt the calamity that faces the Arctic, says Desch, who, like many other scientists, has become alarmed at temperature change in the region. They say that it is now warming twice as fast as their climate models predicted only a few years ago and argue that the 2015 Paris agreement to limit global warming will be insufficient to prevent the region’s sea ice disappearing completely in summer, possibly by 2030.

“Our only strategy at present seems to be to tell people to stop burning fossil fuels,” says Desch. “It’s a good idea but it is going to need a lot more than that to stop the Arctic’s sea ice from disappearing.”

The loss of the Arctic’s summer sea ice cover would disrupt life in the region, endanger many of its species, from Arctic cod to polar bears, and destroy a pristine habitat. It would also trigger further warming of the planet by removing ice that reflects solar radiation back into space, disrupt weather patterns across the northern hemisphere and melt permafrost, releasing more carbon gases into the atmosphere.

Hence Desch’s scheme to use wind pumps to bring water that is insulated from the bitter Arctic cold to its icy surface, where it will freeze and thicken the ice cap. Nor is the physicist alone in his Arctic scheming: other projects to halt sea-ice loss include one to artificially whiten the Arctic by scattering light-coloured aerosol particles over it to reflect solar radiation back into space, and another to spray sea water into the atmosphere above the region to create clouds that would also reflect sunlight away from the surface.

All the projects are highly imaginative – and extremely costly. The fact that they are even being considered reveals just how desperately worried researchers have become about the Arctic. “The situation is causing grave concern,” says Professor Julienne Stroeve, of University College London. “It is now much more dire than even our worst case scenarios originally suggested.’

Last November, when sea ice should have begun thickening and spreading over the Arctic as winter set in, the region warmed up. Temperatures should have plummeted to -25C but reached several degrees above freezing instead. “It’s been about 20C warmer than normal over most of the Arctic Ocean. This is unprecedented,” research professor Jennifer Francis of Rutgers University told the Guardian in November. “These temperatures are literally off the charts for where they should be at this time of year. It is pretty shocking. The Arctic has been breaking records all year. It is exciting but also scary.”

Nor have things got better in the intervening months. Figures issued by the US National Snow and Ice Data Center (NSIDC), in Boulder, Colorado, last week revealed that in January the Arctic’s sea ice covered 13.38 million sq km, the lowest January extent in the 38 years since satellites began surveying the region. That figure is 260,000 sq km below the level for January last year, which was the previous lowest extent for that month, and a worrying 1.26 million sq km below the long-term average for January.

In fact, sea ice growth stalled during the second week of January – in the heart of the Arctic winter – while the ice cap actually retreated within the Kara and Barents seas, and within the Sea of Okhotsk. Similarly, the Svalbard archipelago, normally shrouded in ice, has remained relatively free because of the inflow of warm Atlantic water along the western part of the island chain. Although there has been some recovery, sea ice remains well below all previous record lows.

This paucity of sea ice bodes ill for the Arctic’s summer months when cover traditionally drops to its lower annual level, and could plunge to a record minimum this year. Most scientists expect that, at current emission rates, the Arctic will be reliably free of sea ice in summer by 2030.

By “free” they mean there will be less than 1m sq km of sea ice left in the Arctic, most of it packed into remote bays and channels, while the central Arctic Ocean over the north pole will be completely open. And by “reliably”, scientists mean there will have been five consecutive years with less than 1m sq km of ice by the year 2050. The first single ice-free year will come much earlier than this, however.

And when that happens, the consequences are likely to be severe for the human and animal inhabitants of the region. An ice-free Arctic will be wide open to commercial exploitation, for example. Already, mining, oil and tourism companies have revealed plans to begin operations – schemes that could put severe strain on indigenous communities’ way of life in the region.

Equally worrying is the likely impact on wildlife, says Stroeve. “Juvenile Arctic cod like to hang out under the sea ice. Polar bears hunt on sea ice, and seals give birth on it. We have no idea what will happen when that lot disappears. In addition, there is the problem of increasing numbers of warm spells during which rain falls instead of snow. That rain then freezes on the ground and forms a hard coating that prevents reindeer and caribou from finding food under the snow.”

Nor would the rest of the world be isolated. With less ice to reflect solar radiation back into space, the dark ocean waters of the high latitudes will warm and the Arctic will heat up even further.

“If you warm the Arctic you decrease the temperature difference between the poles and the mid-latitudes, and that affects the polar vortex, the winds that blow between the mid latitudes and the high latitudes,” says Henry Burgess, head of the Arctic office of the UK Natural Environment Research Council.

“Normally this process tends to keep the cold in the high north and milder air in mid-latitudes but there is an increasing risk this will be disrupted as the temperature differential gets weaker. We may get more and more long, cold spells spilling down from the Arctic, longer and slower periods of Atlantic storms and equally warmer periods in the Arctic. What happens up there touches us all. It is hard to believe you can take away several million sq km of ice a few thousand kilometres to the north and not expect there will be an impact on weather patterns here in the UK.”

For her part, Stroeve puts it more bleakly: “We are carrying out a blind experiment on our planet whose outcome is almost impossible to guess.”

This point is backed by Desch. “Sea ice is disappearing from the Arctic – rapidly. The sorts of options we are proposing need to be researched and discussed now. If we are provocative and get people to think about this, that is good.

“The question is: do I think our project would work? Yes. I am confident it would. But we do need to put a realistic cost on these things. We cannot keep on just telling people, ‘Stop driving your car or it’s the end of the world’. We have to give them alternative options, though equally we need to price them.”

THE BIG SHRINK
The Arctic ice cap reaches its maximum extent every March and then, over the next six months, dwindles. The trough is reached around mid-September at the end of the melting season. The ice growth cycle then restarts. However, the extent of regrowth began slackening towards the end of the last century. According to meteorologists, the Arctic’s ice cover at its minimum is now decreasing by 13% every decade – a direct consequence of heating triggered by increased levels of carbon dioxide in the atmosphere.

Climate change deniers claim this loss is matched by gains in sea ice around the Antarctic. It is not. Antarctic ice fluctuations are slight compared with the Arctic’s plummeting coverage and if you combine the changes at both poles, you find more than a million sq km of ice has been lost globally in 30 years.

https://www.theguardian.com/world/2017/feb/12/plan-to-refreeze-arctic-before-ice-goes-for-good-climate-change

Melting ice could expose Cold War toxic waste

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The army base at Camp Century in Greenland was abandoned in the ’60s, leaving behind buried toxic waste that may become exposed by the end of the century. (Photo: U.S. Army/Wikimedia Commons)

by Sami Grover

When the Cold War ended, much of the world breathed a huge sigh of relief. And while the immediate threat of nuclear armageddon may have faded, there are countless sites around the world that are still burdened with the toxic legacy of military superpowers.

As global climate change reshapes our world, at least one such site is in danger of becoming a more immediate problem.

As reported over at Scientific American, Camp Century in northwest Greenland was a U.S. military base abandoned in the mid-1960s. When American forces shipped out, they left behind literally thousands of tons of waste buried deep inside tunnels that were dug out of the thick, year-round ice. Not unreasonably — given that the tunnels were 120 feet below the surface, and that fresh snow fell every year to bury the tunnels ever deeper — an assumption was made that the waste would remain buried for tens of thousands of years. But we all know what they say about assumptions…

With the rapid rate of Greenland’s ice melt (which CNN reports is off to a record start this year), concerns are surfacing that the buried waste — which includes everything from radioactive coolant to toxic PCBs — will be exposed much sooner than previously thought. A new study led by glaciologist William Colgan of York University in Toronto suggests that while cleaning up the site will have to wait until melting brings it closer to the surface, now would be a good time for world powers to start thrashing out who is responsible for such long abandoned waste materials.

http://www.mnn.com/earth-matters/climate-weather/stories/melting-ice-could-expose-cold-war-toxic-waste

Drought causes 450-year-old Mexican church to emerge from reservoir


The Temple of Quechula was built in 1564 but later abandoned and ultimately submerged by a dam. Now drought conditions in Chiapas have seen it rise again.

The ruins of a 16th century church have emerged from the waters of a reservoir in Mexico.

The water level in the Nezahualcóyotl reservoir in Chiapas state has dropped by 25m (82ft) because of a drought in the area. The church, known as the Temple of Santiago or the Temple of Quechula, has been under nearly 100ft of water since 1966.

The church, which is believed to have been built by Spanish colonists, is 183ft long and 42ft wide, with a bell tower that rises 48ft above the ground.

It was built in 1564, the Associated Press reported, because of an expected surge in population, but abandoned after plague hit the area between 1773 and 1776.

“It was a church built thinking that this could be a great population center, but it never achieved that,” architect Carlos Navarretes said. “It probably never even had a dedicated priest, only receiving visits from those from Tecpatán.”

http://www.theguardian.com/world/2015/oct/19/drought-mexican-church-reservoir

Risk of American ‘megadroughts’ for decades, NASA warns

There is no precedent in contemporary weather records for the kinds of droughts the country’s West will face, if greenhouse gas emissions stay on course, a NASA study said.

No precedent even in the past 1,000 years.

The feared droughts would cover most of the western half of the United States — the Central Plains and the Southwest.

Those regions have suffered severe drought in recent years. But it doesn’t compare in the slightest to the ‘megadroughts’ likely to hit them before the century is over due to global warming.
These will be epochal, worthy of a chapter in Earth’s natural history.

Even if emissions drop moderately, droughts in those regions will get much worse than they are now, NASA said.

The space agency’s study conjures visions of the sun scorching cracked earth that is baked dry of moisture for feet below the surface, across vast landscapes, for decades. Great lake reservoirs could dwindle to ponds, leaving cities to ration water to residents who haven’t fled east.

“Our projections for what we are seeing is that, with climate change, many of these types of droughts will likely last for 20, 30, even 40 years,” said NASA climate scientist Ben Cook.

That’s worse and longer than the historic Dust Bowl of the 1930s, when “black blizzards” — towering, blustery dust walls — buried Southern Plains homes, buggies and barns in dirt dunes.

It lasted about 10 years. Though long, it was within the framework of a contemporary natural drought.

To find something almost as extreme as what looms, one must go back to Medieval times.

Nestled in the shade of Southwestern mountain rock, earthen Ancestral Pueblo housing offers a foreshadowing. The tight, lively villages emptied out in the 13th century’s Great Drought that lasted more than 30 years.

No water. No crops. Starvation drove populations out to the east and south.

If NASA’s worst case scenario plays out, what’s to come could be worse.

Its computations are based on greenhouse gas emissions continuing on their current course. And they produce an 80% chance of at least one drought that could last for decades.

One “even exceeding the duration of the long term intense ‘megadroughts’ that characterized the really arid time period known as the Medieval Climate Anomaly,” Cook said.

That was a period of heightened global temperatures that lasted from about 1100 to 1300 — when those Ancestral Pueblos dispersed. Global average temperatures are already higher now than they were then, the study said.

The NASA team’s study was very data heavy.

It examined past wet and dry periods using tree rings going back 1,000 years and compared them with soil moisture from 17 climate models, NASA said in the study published in Science Advances.

Scientists used super computers to calculate the models forward along the lines of human induced global warming scenarios. The models all showed a much drier planet.

Some Southwestern areas that are currently drought-stricken are filling up with more people, creating more demand for water while reservoirs are already strained.

The predicted megadroughts will wrack water supplies much harder, NASA Goddard Space Flight Center said.

“These droughts really represent events that nobody in the history of the United States has ever had to deal with,” Cook said.

Compared with the last millennium, the dryness will be unprecedented. Adapting to it will be tough.

http://www.cnn.com/2015/02/14/us/nasa-study-western-megadrought/index.html

New research projects that climate change may increase female:male ratio

Climate change could affect the ratio of human males to human females that are born in some countries, a new study from Japan suggests. The researchers found that male fetuses may be particularly vulnerable to the effects of climate change.

Since the 1970s, temperature fluctuations from the norm have become more common in Japan, and at the same time there has been an increase in the deaths of male fetuses, relative to the number of deaths of female fetuses in that country, according to the study.

Over this period, the ratio of male to female babies born in the country has been decreasing, meaning there have been fewer and fewer male babies born relative to the number of female babies born.

http://www.livescience.com/48070-male-fetus-climate-change.html

Underground volcanoes spur Antarctic glacier melt

Glaciers in Antarctica are being melted not only by warmer ocean waters but also by underwater volcanoes, a change in our basic understanding of what’s happening underneath West Antarctica’s ice sheet, scientists say.

Geothermal heat from underneath is helping melt the region’s Thwaites Glacier, in the headlines recently for its rapid melt and retreat, researchers at the University of Texas at Austin say.

Scientists in the university’s Institute for Geophysics say they used ice-penetrating radar aboard aircraft to find significant geothermal heat sources — hotter and spread over a broader area than previously thought — underneath the glacier.

Caused by magma moving underground and volcanic activity associated with that movement, geothermal heat might represent a significant factor in changing the stability of the ice mass above, they researchers reported in the Proceedings of the National Academy of Sciences.

Rather than a uniform region of heat beneath, like a pancake griddle, geothermal sources under the Thwaites Glacier more resemble a stove top with a multitude of burners emitting heat in different locations and at different levels, research scientist Don Blankenship says.

“It’s the most complex thermal environment you might imagine,” he says. “And then you plop the most critical dynamically unstable ice sheet on planet Earth in the middle of this thing, and then you try to model it. It’s virtually impossible.”

The geothermal heat under the glacier averages around 100 milliwatts in each square meter, the researchers said, with some hotspots putting out 200 milliwatts per square meter.

Under the Earth’s other continents the average is less than 65 milliwatts per square meter, they said.

The Thwaites Glacer is an outflow glacier — pushing into the Amundsen Sea — that is the size of Florida and hold the key to trying to predict possible future rises in sea levels, they said.

Studying it could help yield clues to the future state of the entire West Antarctic Ice sheet, they added.

A complete collapse of Thwaites Glacier could push global sea levels up by three to six feet, and a melting of the entire ice sheet could double that, the researchers said.

The combination of warm ocean water and underlying geothermal heat makes the future of the glacier difficult to predict, lead study author Dusty Schroeder says.

“The combination of variable subglacial geothermal heat flow and the interacting subglacial water system could threaten the stability of Thwaites Glacier in ways that we never before imagined,” he says.

http://www.techtimes.com/articles/8268/20140610/underground-volcanoes-spur-antartic-glaciar-melt.htm

Scientists at Duke University say the world is on the brink of its sixth great extinction

Is the end near? Scientists at Duke University say the world is on the brink of its sixth great extinction, since certain species of plants and animals are now dying out at least 1,000 times faster than they did before humans came into existence.

The study, published Thursday in the journal Science, measured the the rate at which species are disappearing from Earth. In 1995, the researchers found that the pre-human rate of extinctions was roughly 1. Now, that rate is about 100 to 1,000.

Stuart Pimm, the study’s lead author, said habitat loss is mostly to blame for the increasing death rates. As humans continue to alter and destroy more land, animals and plants are increasingly being displaced from their natural habitats. Climate change is also a factor, he added.

“Whether we avoid it or not will depend on our actions,” Pimm warned.

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

http://theweek.com/article/index/262400/speedreads-earth-is-nearing-sixth-great-extinction-alarming-survey-says#axzz33DjJqxZg

CO2 causing oceans to acidify at ‘unprecedented’ rate, scientists warn

<> on June 9, 2010 in Houma, Louisiana.

By Susannah Cullinane, CNN

The world’s oceans have become 26% more acidic since the start of the Industrial Revolution and continue to acidify at an “unprecedented rate,” threatening marine ecosystems, aquaculture and the societies that rely on them, scientists say.

In a report released Thursday, researchers say that carbon dioxide emissions from human activities such as fossil fuel burning are the primary cause of ocean acidification.

They say the rate of change may be faster than at any time in the last 300 million years, predicting that by 2100 there will have been a 170% increase in ocean acidity, compared to pre-industrial times.

The report is based on the findings from a September 2012 Symposium on the Ocean, at which 540 experts from 37 countries discussed research on ocean acidification, and has been updated with more recent research.

Unless carbon dioxide emissions are reduced, marine ecosystems will be damaged and the impact of climate change will be worsened, the scientists warn. “The only known realistic mitigation option on a global scale is to limit future atmospheric CO2 levels.”

The report says oceans currently act as a CO2 “sinkhole” absorbing approximately a quarter of emissions.

“As ocean acidity increases, its capacity to absorb CO2 from the atmosphere decreases. This decreases the ocean’s role in moderating climate change,” they write.

The increased acidity will also change the ocean environment, with evidence suggesting that some organisms will be less able to survive, while others, such as seagrass, may thrive.

Acidification is faster in Arctic waters because cold water is richer in CO2, while melting sea ice worsens the problem, they say.

“Within decades, large parts of the polar oceans will become corrosive to the unprotected shells of calcareous marine organisms,” the report says, while in the tropics the growth of coral reefs may be hampered.

“People who rely on the ocean’s ecosystem services are especially vulnerable and may need to adapt or cope with ocean acidification impacts within decades,” it says. “Tropical coral reef loss will affect tourism, food security and shoreline protection for many of the world’s poorest people.”

“Very aggressive reductions in CO2 emissions are required to maintain a majority of tropical coral reefs in waters favorable for growth,” the report says.

One of the report’s authors is Daniela Schmidt, from the University of Bristol, in the UK.

Schmidt said the research highlighted the impact acidification would have on biodiversity and aquaculture and the societies that rely on them for their food and economic well-being.

“We’re talking about countries that strongly depend on this, in warmer countries where there are complex problems with climate change as it is,” Schmidt said.

“What I’m hoping is that people realize that CO2 is not just a question of global warming. That we are acidifying the ocean at a rate that has been unprecedented — for millions and millions of years,” she said.

“The more CO2 emissions, the more acidification,” Schmidt said. “The ocean is in direct interchange with the atmosphere.”

If acidification continued to increase at its current rate, “you will definitely see damage,” she said. “The first signs we can already see today, in oyster farms off the West Coast of the United States.”

Schmidt said while 90% of the world’s ocean was in equilibrium with the atmosphere, some oyster hatcheries in this area were located in the 10% that wasn’t.

Oysters in the larval stage were much more vulnerable to damage, she said. “When (more acidic) water comes up and hits the hatchery, they close the whole thing.”

While tanks could be closed off to more acidic seawater, Schmidt said that by 2100 the issue would be there every day. “So we can’t just switch off that tap anymore.”

She said the report would be presented in Warsaw, Poland, on November 18, during the U.N. Conference of the Parties climate change meeting.

Schmidt said while she hoped the research would lead to stricter emissions limits, “the realist in me thinks that we’ve been discussing this for decades. This isn’t a problem that is just going to go away. It’s simple. The consequences are frightening.”

The 2012 symposium that led to the report was sponsored by the Scientific Committee on Oceanic Research, the Intergovernmental Oceanographic Commission of UNESCO, and the International Geosphere-Biosphere Programme.

http://www.cnn.com/2013/11/14/world/ocean-acidification-report/index.html?hpt=hp_t3

Top climate scientists ask environmentalists to support nuclear power in climate battle

Some of the world’s top climate scientists say wind and solar energy won’t be enough to head off extreme global warming, and they’re asking environmentalists to support the development of safer nuclear power as one way to cut fossil fuel pollution.

Four scientists who have played a key role in alerting the public to the dangers of climate change sent letters Sunday to leading environmental groups and politicians around the world. The letter, an advance copy of which was given to The Associated Press, urges a crucial discussion on the role of nuclear power in fighting climate change.

Environmentalists agree that global warming is a threat to ecosystems and humans, but many oppose nuclear power and believe that new forms of renewable energy will be able to power the world within the next few decades.

That isn’t realistic, the letter said.

“Those energy sources cannot scale up fast enough” to deliver the amount of cheap and reliable power the world needs, and “with the planet warming and carbon dioxide emissions rising faster than ever, we cannot afford to turn away from any technology” that has the potential to reduce greenhouse gases.

The letter signers are James Hansen, a former top NASA scientist; Ken Caldeira, of the Carnegie Institution; Kerry Emanuel, of the Massachusetts Institute of Technology; and Tom Wigley, of the University of Adelaide in Australia.

Hansen began publishing research on the threat of global warming more than 30 years ago, and his testimony before Congress in 1988 helped launch a mainstream discussion. Last February he was arrested in front of the White House at a climate protest that included the head of the Sierra Club and other activists. Caldeira was a contributor to reports from the Intergovernmental Panel on Climate Change, Emanuel is known for his research on possible links between climate change and hurricanes, and Wigley has also been doing climate research for more than 30 years.

Emanuel said the signers aren’t opposed to renewable energy sources but want environmentalists to understand that “realistically, they cannot on their own solve the world’s energy problems.”

The vast majority of climate scientists say they’re now virtually certain that pollution from fossil fuels has increased global temperatures over the last 60 years. They say emissions need to be sharply reduced to prevent more extreme damage in the future.

In 2011 worldwide carbon dioxide emissions jumped 3 per cent, because of a large increase by China, the No. 1 carbon polluting country. The U.S. is No. 2 in carbon emissions.

Hansen, who’s now at Columbia University, said it’s not enough for environmentalists to simply oppose fossil fuels and promote renewable energy.

“They’re cheating themselves if they keep believing this fiction that all we need” is renewable energy such as wind and solar, Hansen told the AP.

The joint letter says, “The time has come for those who take the threat of global warming seriously to embrace the development and deployment of safer nuclear power systems” as part of efforts to build a new global energy supply.

Stephen Ansolabehere, a Harvard professor who studies energy issues, said nuclear power is “very divisive” within the environmental movement. But he added that the letter could help educate the public about the difficult choices that climate change presents.

One major environmental advocacy organization, the Natural Resources Defence Council, warned that “nuclear power is no panacea for our climate woes.”

Risk of catastrophe is only one drawback of nuclear power, NRDC President Frances Beinecke said in a statement. Waste storage and security of nuclear material are also important issues, he said.

“The better path is to clean up our power plants and invest in efficiency and renewable energy.”

The scientists acknowledge that there are risks to using nuclear power, but say those are far smaller than the risk posed by extreme climate change.

“We understand that today’s nuclear plants are far from perfect.”

http://www.ottawacitizen.com/technology/climate+scientists+environmentalists+support+nuclear+power/9118639/story.html

International Panel on Climate Change (IPCC) issues new stark warning over global warming

bnurning earth

Scientists will this week issue their starkest warning yet about the mounting dangers of global warming. In a report to be handed to political leaders in Stockholm on Monday, they will say that the burning of fossil fuels and deforestation have now led to a warming of the entire globe, including land surfaces, oceans and the atmosphere.

Extreme weather events, including heatwaves and storms, have increased in many regions while ice sheets are dwindling at an alarming rate. In addition, sea levels are rising while the oceans are being acidified – a development that could see the planet’s coral reefs disappearing before the end of the century.

Writing in the Observer ahead of the report’s release, the economist and climate change expert Lord Stern calls on governments to end their dithering about fossil fuels and start working to create a global low-carbon economy to curtail global warming. Governments, he states, must decide what “kind of world we want to present to our children and grandchildren”.

The fifth assessment report on the physical science of climate change by the Intergovernmental Panel on Climate Change (IPCC) warns that humanity is on course over the next few decades to raise global temperatures by more than 2C compared with pre-industrial levels. Such a rise could trigger the release of plumes of the greenhouse gas methane from the thawing Arctic tundra, while the polar ice caps, which reflect solar radiation back into space, could disappear.

Although the report does not say so, Earth would probably then be facing a runaway greenhouse effect.

The scientists’ warning – the most comprehensive and convincing yet produced by climate scientists – comes at a time when growing numbers of people are doubting the reality of global warming. Last week, the UK Energy Research Centre (UKERC) published a survey showing that the proportion of British people who do not think the world’s climate is changing has almost quadrupled since 2005.

Asked if they thought Earth’s climate was changing, 5% of respondents said “no” in 2005, a figure that rose to 11% last year and reached 19% this year.

But as the IPCC report underlines, scientists are becoming more and more certain that climate change poses a real danger to the planet.

Many believe the disconnection between popular belief and scientific analysis has been engineered by “deniers” explicitly opposed to the lifestyle changes – including restrictions on fossil fuel burning – that might be introduced in the near future.

“There are attempts by some politicians and lobbyists to confuse and mislead the public about the scientific evidence that human activities are driving climate change and creating huge risks,” said Stern.

“But the public should be wary of those who claim they know for certain that unmanaged climate change would not be dangerous. For they are not only denying 200 years of strong scientific evidence – the overwhelming view of the world’s scientific academies and over 95% of scientific papers on the subject – but they are often harbouring vested interests or rigid ideologies as well.”

The report will be discussed this week by political leaders meeting in Stockholm. The study – the work of more than 200 scientists – outlines the physical changes that are likely to affect Earth’s climate this century.

Future reports will cover the social impact of these changes and the efforts required to offset the damage caused by global warming. A United Nations meeting in Paris in 2015 will then debate what actions are needed to mitigate climate change.

According to the new report, humanity has emitted about half a trillion tonnes of carbon by burning fossil fuels over the past 250 years, a process that has caused atmospheric carbon dioxide levels to rise by 40%. The world is now on target to release another half trillion tonnes in the next few decades which could trigger a major jump in global temperatures.

Most measures that have been proposed for tackling global warming rely on curtailing the burning of fossil fuels and these will form the focus of the 2015 UN meeting in Paris. Given the poor record of previous summits, many are pessimistic an agreement can be reached.

However, other measures have been suggested to curb global warming. In particular, many scientists have backed geo-engineering projects that would involve either spraying particles into the atmosphere to reflect solar radiation back into space or extracting carbon dioxide from the atmosphere in order to bury it in mines or depleted oil fields.

Both suggestions get short shrift in the new report: atmospheric aerosols could have widespread side-effects that could produce major disruptions to weather patterns, while not enough is known about the effectiveness of carbon dioxide extraction or burial. “We have to face up to the prospect of weaning ourselves off our addiction to oil and coal,” said one report author. “It is as simple as that.”

http://www.theguardian.com/environment/2013/sep/21/climate-change-ipcc-global-warming

Thanks to Mr. C for bringing this to the attention of the It’s Interesting community.