Tag Archives: Intergovernmental panel on climate change

Climate Change–procrastinators and their victims

KIRIBATI. image from http://climatechange.dreamhosters.com/_old/CAUSES-EFFECTS/KIRIBATI.jpg

Global carbon emissions were 58% higher in 2012 than they were in 1990. The atmospheric concentration of carbon dioxide has risen from just under 340 parts per million in 1980 to 400 in 2015.  To stand a fair chance of keeping warming to just 2°C by the end of the century—the goal of global climate policy—cumulative carbon emissions caused by humans must be kept under 1 trillion tonnes. Estimates vary but, according to the Intergovernmental Panel on Climate Change, the total had hit 515 billion tonnes by 2011. Climate Interactive, a research outfit, reckons that if emissions continue on their present course around 140 billion tonnes of greenhouse gases will be released each year and temperatures could rise by 4.5°C by 2100. And even if countries fully honour their recent pledges, temperatures may still increase by 3.5°C by then.

The world is already 0.75°C warmer than before the Industrial Revolution….

Melting glacier ice, and the fact that warmer water has a larger volume, mean higher sea levels: they have already risen by roughly 20cm since 1880 and could rise another metre by 2100. That is perilous for low-lying islands and flat countries: the government of Kiribati, a cluster of tropical islands, has bought land in Fiji to move residents to in case of flooding. Giza Gaspar Martins, a diplomat from Angola who leads the world’s poorest countries in the climate talks, points out that they are particularly vulnerable to the effects of a warming planet. Money alone, he argues, will not fix their problems. Without steps to reduce emissions, he predicts, “there will be nothing left to adapt for.”…

For every 0.6°C rise in temperature, the atmosphere’s capacity to hold water grows by 4%, meaning storms will pour forth with greater abandon. The rains of the Indian monsoon could therefore intensify, cutting yields of cereals and pulses.

Climate change seems also to be making dry places drier, killing crops and turning forests into kindling. Forest fires in Indonesia, more likely thanks to the current El Niño weather phenomenon, could release 2 billion tonnes of carbon dioxide, about 5% of annual emissions due to human activity, says Simon Lewis of University College London. In recent months fires have swallowed more than 2.4m hectares of American forests. Alaska suffered 80% of the damage—a particular problem because the soot released in these blazes darkens the ice, making it less able to reflect solar radiation away from the Earth.

Developments in the Arctic are worrying for other reasons, too. The region is warming twice as fast as the rest of the world, a trend that could start a vicious cycle. Around 1,700 gigatonnes of carbon are held in permafrost soils as frozen organic matter. If they thaw, vast amounts of methane, which is 25 times more powerful as a global-warming gas than carbon dioxide when measured over a century, will be released. One hypothesis suggests that self-reinforcing feedback between permafrost emissions and Arctic warming caused disaster before: 55m years ago temperatures jumped by 5°C in a few thousand years…

And on September 29th Mark Carney, the governor of the Bank of England, warned that though measures to avoid catastrophic climate change are essential, not least for long-term financial stability, in the shorter term they could cause investors huge losses by making reserves of oil, coal and gas “literally unburnable”.

Excerpts from Climate Change: It’s Getting Hotter, Economst, Oct. 3, 2015, at 63

 

Climate Change Politics: IPCC report leaked 2013

Carbon_dioxide_3D_ball, Ball-and-stick model of the carbon dioxide molecule. Oxygen in red, carbon in black

Climate sensitivity [:]This is the measure used by researchers of how much they expect the world’s average temperature to increase in response to particular increases in levels of carbon dioxide in the atmosphere. According to one table from the unpublished [IPCC] report, which was seen by The Economist, at CO2 concentrations of between 425 parts per million and 485 ppm, temperatures in 2100 would be 1.3-1.7°C above their pre-industrial levels. That seems lower than the IPCC’s previous assessment, made in 2007. Then, it thought concentrations of 445-490 ppm were likely to result in a rise in temperature of 2.0-2.4°C.

climate change leaked report 2013

(Source the Economist, July 20, 2013, at 71)

The two findings are not strictly comparable. The 2007 report talks about equilibrium temperatures in the very long term (over centuries); the forthcoming one talks about them in 2100. But the practical distinction would not be great so long as concentrations of CO2 and other greenhouse-gas emissions were stable or falling by 2100. It is clear that some IPCC scientists think the projected rise in CO2 levels might not have such a big warming effect as was once thought.

There are several caveats. The table comes from a draft version of the report, and could thus change. It was put together by the IPCC working group on mitigating climate change, rather than the group looking at physical sciences. It derives from a relatively simple model of the climate, rather than the big complex ones usually used by the IPCC. And the literature to back it up has not yet been published.

Still, over the past year, several other papers have suggested that views on climate sensitivity are changing. Both the 2007 IPCC report and a previous draft of the new assessment reflected earlier views on the matter by saying that the standard measure of climate sensitivity (the likely rise in equilibrium temperature in response to a doubling of CO2 concentration) was between 2°C and 4.5°C, with 3°C the most probable figure. In the new draft, the lower end of the range has been reduced to 1.5°C and the “most likely” figure has been scrapped. That seems to reflect a growing sense that climate sensitivity may have been overestimated in the past and that the science is too uncertain to justify a single estimate of future rises.

If this does turn out to be the case, it would have significant implications for policy. Many countries’ climate policies are guided by the IPCC’s findings. They are usually based on the idea (deriving in part from the IPCC) that global temperatures must not be allowed to increase by more than 2°C above pre-industrial levels, and that in order to ensure this CO2 concentrations should not rise above 450 ppm. The draft table casts doubt on how solid the link really is between 450 ppm and a 2°C rise. It remains to be seen whether governments conclude from this that it is safe to let CO2 concentrations climb even further, or whether (as some will doubtless argue) a 2°C rise was too much anyway and it is now possible to aim for less.

Excerpt, Climate science: Sensitive information, Economist, July 20, 2013, at 70

See also Coerced Transparency: the leaked IPCC Report 2012

Coerced Transparency: the Leaked Climate Change Report

Satellite image of w:ship tracks, clouds created by the exhaust of ship smokestacks. Image from wikipedia

The fifth assessment report (AR5) by the Intergovernmental Panel on Climate Change, which is not due to be published in full until September 2013, was uploaded onto a website called Stop Green Suicide on Thursday and has since been mirrored elsewhere on the internet.  The IPCC, which confirmed the draft is genuine, said in a statement: “The IPCC regrets this unauthorized posting which interferes with the process of assessment and review. We will continue not to comment on the contents of draft reports, as they are works in progress.”

A little-known US-based climate sceptic called Alex Rawls, who had been accepted by the IPCC to be one of the report’s 800 expert reviewers, admitted to leaking the document. In a statement posted online, he sought to justify the leak: “The addition of one single sentence [discussing the influence of cosmic rays on the earth’s climate] demands the release of the whole. That sentence is an astounding bit of honesty, a killing admission that completely undercuts the main premise and the main conclusion of the full report, revealing the fundamental dishonesty of the whole.”  Climate sceptics have heralded the sentence – which they interpret as meaning that cosmic rays could have a greater warming influence on the planet than mankind’s emissions – as “game-changing”.

The isolation by climate sceptics of one sentence in the 14-chapter draft report was described as “completely ridiculous” by one of the report’s lead authors. Prof Steve Sherwood, a director of the Climate Change Research Centre at the University of New South Wales, told ABC Radio in Australia: “You could go and read those paragraphs yourself and the summary of it and see that we conclude exactly the opposite, that this cosmic ray effect that the paragraph is discussing appears to be negligible … It’s a pretty severe case of [cherry-picking], because even the sentence doesn’t say what [climate sceptics] say and certainly if you look at the context, we’re really saying the opposite.”  The leaked draft “summary for policymakers” contains a statement that appears to contradict the climate sceptics’ interpretation.  It says: “There is consistent evidence from observations of a net energy uptake of the earth system due to an imbalance in the energy budget. It is virtually certain that this is caused by human activities, primarily by the increase in CO2 concentrations. There is very high confidence that natural forcing contributes only a small fraction to this imbalance.”  By “virtually certain”, the scientists say they mean they are now 99% sure that man’s emissions are responsible. By comparison, in the IPCC’s last report, published in 2007, the scientists said they had a “very high confidence” – 90% sure – humans were principally responsible for causing the planet to warm.

Richard Betts, a climate scientist at the Met Office Hadley Centre and an AR5 lead author, tweeted that the report is still a draft and could well change: “Worth pointing out that the wording in the leaked IPCC WG1 [working group 1, which examines the “physical science basis” of climate change] draft chapters may still change in the final versions, following review comments.”  Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics and Political Science, said that Rawls appeared to have broken the confidentiality agreement signed by reviewers: “As a registered reviewer of the IPCC report, I condemn the decision by a climate change sceptic to violate the confidentiality of the review process. The review of the IPCC report is being carried out in line with the principles of peer review which operate throughout academic science, including an expectation of high standards of ethical behaviour by reviewers. It is disappointing, if not surprising, that climate change sceptics have been unable to meet these high standards of ethical behaviour.”

The IPCC, which publishes a detailed synthesis of the latest climate science every seven years to help guide policy makers, has experienced leaks before. In 2000, the third assessment report was leaked to the New York Times, while the fourth assessment report was published in 2006 by the US government a year ahead of its official publication.

Prof Bill McGuire, Professor of Geophysical & Climate Hazards at University College London and contributing author on the recent IPCC report on climate change and extreme events, said that sceptics’ reading of the draft was incorrect: “Alex Rawls’ interpretation of what IPCC5 says is quite simply wrong. In fact, while temperatures have been ramping up in recent decades, solar activity has been pretty subdued, so any interaction with cosmic rays is clearly having minimal – if any – effects. IPCC AR5 reiterates what we can be absolutely certain of: that contemporary climate change is not a natural process, but the consequence of human activities.”

Prof Piers Forster, Professor of Climate Change at the University of Leeds, said: “Although this may seem like a ‘leak’, the draft IPCC reports are not kept secret and the review process is open. The rationale in not disseminating the findings until the final version is complete, is to try and iron out all the errors and inconsistencies which might be inadvertently included. Personally, I would be happy if the whole IPCC process were even more open and public, and I think we as scientists need to explore how we can best match the development of measured critical arguments with those of the Twitter generation.”

Landmark climate change report leaked online, Guardian, Dec. 14,2012

Climate Change: Walking on Broken Ice

If they could only build a robust climate model…the following from Canada.com

Forecasts of an ice-free Arctic summer by 2100 may be underestimating climate change trends in the region, new research suggests.  The Intergovernmental Panel on Climate Change Fourth Assessment Report, released in 2007, forecast an ice-free Arctic summer by 2100. But that might happen much earlier, according to research by Pierre Rampal from MIT’s department of Earth, Atmosphere and Planetary Sciences, says an MIT news release on research to be published in the Journal of Geophysical Research — Oceans.

IPCC models focused on changes in temperature, which are one way to lose or gain ice. But Rampal said wind and ocean currents also batter the ice, causing it to break up. And ice that’s in small pieces behaves differently than ice in one large mass.  Wind and currents also play a significant role in winter, when they can cause “drastic effects” on the ice’s shape and movement, he said.

As today’s Arctic Ocean winter ice cover is thinner, it breaks up more easily under the influence of winds and currents. So, eventually it looks like an “ensemble of floes” instead of one large mass, Rampal said.  In summer, natural melting due to warmer temperatures opens the door to even more breakup, he said.  However, large cracks in the winter’s ice cover can help create new ice, since the extremely cold air in contact with the liquid ocean promotes refreezing.  This means “it’s hard to predict the future of Arctic sea ice,” said Rampal.  Rampal is working on a project with researchers at MIT and NASA’s Jet Propulsion Laboratory to combine models and observations which will produce a more accurate picture of what’s happening.

Arctic Ocean to lose ice faster than predicted: MIT, Canada.com, Aug. 10, 2011