the climate brief Accurate Reporting of Climate Science

Could laptop models help negotiators imagine the impacts of climate change? How could emissions accounting be improved to include land use? With the UN's COP18 international climate talks starting today, we look at some recent developments in science and political research that can play a part in helping countries cut their greenhouse gas emissions.

Upper limits

Climate scientists' predictions go to the heart of the UNFCCC process. Scientists first suggested in 2007 that to avoid serious climate change, global mean temperature rise should not exceed two degrees Celsius above pre-industrial levels. But as three different reports out last week highlight, this target looks increasingly unrealistic.

According to the World Meteorological Office (WMO), carbon dioxide has continued to rise at a fairly constant rate  for the past decade, reaching a record high this year along with methane and nitrous oxide - two other important greenhouse gases.

The United Nations Environment Programme has said the "emissions gap" - the difference between government pledges to reduce emissions and what is needed to stabilise global temperature rise at two degrees - is widening.  And according to the World Bank, without further action, the world is likely to warm by more than three degrees.

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Major droughts in the United States and  Russia this summer highlighted the risks climate extremes pose to everyday life, and prompted discussion about links between drought and climate change.

Past research supports a link between climate change and drought - suggesting that globally, the area affected by drought has increased in recent decades as global temperatures have risen.

But a new study in Nature challenges this link, suggesting that the relationship might not be that simple, and that older models may have overestimated the change in drought over the last 60 years. In fact, newer models which take a more detailed look at the how droughts occur suggest the world area in drought may not have changed much at all.

We take a look at the new research and why overestimating the past might not affect predictions of how drought may respond to climate change in the future.

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If you feel like summers have been getting warmer, new research suggests you might be onto something. A new study shows that in many parts of the world, summers have got significantly warmer in recent decades, in some areas since as early as the 1960s.

In the study, scientists looked at the speed at which local temperatures have changed across the globe since 1920. They found that in many locations, summer temperatures have gone up by a statistically significant amount due to manmade climate change. Many parts of the world are now experiencing a new summer climate, say the researchers - it's not only on the global scale that temperatures are changing.

The research, carried out by a team of researchers from the US National Oceanic and Atmospheric Administration and the University of Colorado at Boulder, is published in Geophysical Research Letters.

Temperature trends

Temperature measurements from around the world tell us that the earth has warmed by about 0.8 degrees since 1900. This trend is clear because the change in average temperature exceeds the bounds of natural variability -  and persists for more than a few isolated years. 

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When scientists talk about ice and climate change, it's often about how quickly it's disappearing. So recent  news stories  about Antarctic sea ice growing may come as a surprise. 

The amount of ice in the ocean around Antarctica is indeed increasing, but this is only part of what's going on in the Antarctic as a whole. We've put together six things you should know about climate change and Antarctic ice.

1. Antarctic waters are warming faster than the global average

Along with the rest of the world, the Antarctic is warming up. The Southern Ocean, which surrounds the continent of Antarctica, has been warming faster than the rest of the world's oceans since the 1950s, at a rate of  0.17 degrees Celsius compared to a global average of 0.1 degrees. The increased rate of warming is mainly due to the way large weather systemstransport heat to the poles.

2. Despite rapid warming, there's more Antarctic sea ice

Despite rapidly warming water, the amount of ice that floats on the Southern Ocean around Antarctica - known as sea ice - is slightly increasing. On 26 September this year, the USNational Snow and Ice Data Centre (NSIDC) confirmed that Antarctic sea ice reached a record extent - a measure of sea ice cover - of 19.44 million square kilometres.

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As part of our look at media coverage linked to Hurricane Sandy, we look at Telegraph columnist Fraser Nelson's arguments in favour of dropping attempts to slow climate change and focusing on adapting to new conditions.

Hurricane Sandy has prompted new interest in the media over the links between climate change and extreme weather, but journalist Fraser Nelson took a different tack. Writing in the Telegraph, he says New York's response to the storm shows that while efforts to mitigate climate change are faltering, humans are already adapting successfully to the effects of higher temperatures. He says:

"[A]s science evolves, the hysteria is draining out of the climate change debate - and a new rationalism taking its place. We might not be sure that we can make any meaningful difference to its trajectory, but we know that we can adapt to it."

To support his argument, Nelson makes several claims about research on climate change and extreme weather and the ability of different countries to adapt. We take a look at some of them.

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A new study has highlighted the Arctic's pivotal position in influencing the world's climate. 
The research suggests that a flood of meltwater from the Arctic thousands of years ago triggered an abrupt return to glacial conditions in Europe. So can the study tell us anything about the role of Arctic meltwater in future climate change?

The  study by American researchers, published yesterday in the Proceedings of the National Academy of Sciences (PNAS), describes how meltwater formerly trapped in glacially dammed lakes flooded the North Atlantic as the earth warmed about 13,000 years ago.

The freshwater flood disrupted deep ocean circulation and caused a several degree drop in atmospheric temperature in the northern hemisphere, nicknamed 'The Big Freeze'.

This finding is important, say the researchers, because it identifies the Arctic as a "key geographical area for triggering global climate episodes".

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As millions of people on the US east coast remain without power in the wake of hurricane Sandy, the media are still speculating over how far the storm can be linked to climate change. With a complicated range of factors affecting hurricane activity, we asked climate scientists how satisfied they are that the media got it right this time?

Measured media

Hurricane Sandy tore through the Caribbean and the US east coast last week, killing 160 people and causing $20 billion worth of damage. As the Guardian points out, Sandy has forced climate change further up the political and media agenda. Emilee Pierce from US media fact-checking website, Media Matters, told us:

"In the days leading up to landfall in the U.S...very few in the press mentioned the words 'climate change.' But once it hit New York and DC...the connections started coming -- from journalists and politicians alike."

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A Nature study released yesterday says that warming of the Gulf Stream in the past 5000 years has triggered the release of methane into the ocean that was once locked up in the seafloor. Since methane is a potent greenhouse gas, we ask how will the release affect global warming. 

Under high pressure and low temperature in the sea bed, methane combines with water to form frozen methane hydrate. Some scientists have raised concern that rising ocean temperatures could thaw hydrates, potentially releasing methane to the atmosphere. Scientists have already found that  ten times more methane  is escaping from melting permafrost in the Arctic than previously thought.

Since methane is a powerful greenhouse gas, around 30 times  more potent than carbon dioxide, researchers fear that methane in large enough quantities in the atmosphere couldaccelerate global warming. This has led some media outlets to talk about gas hydrates as  "the methane time bomb". We have discussed the appropriateness - or otherwise - of this phrase before.

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Last week was a  big week for skeptics and climate scientists debating the long-standing (but  wrong) claim that global warming has stopped. Just to recap, skeptic journalist David Rose provoked  a huge response following his article in the Mail on Sunday last week, entitled "global warming stopped 16 years ago - and here's the graph to prove it". He suggested that the alleged finding was contained in a Met Office report that had been released under the radar. 

Although the Met Office and a host of scientists, commentators and bloggers criticised Rose's analysis, he published another article in this week's Mail on Sunday  sticking to his original story. Rather than treading more carefully around the scientific data this time, Rose made no acknowledgement of his previous mistakes and even threw a few more erroneous claims in for good measure.

The new article includes a climate Q and A and an invitation for readers to "decide what the real facts are". So we do just that by taking a look at what he says this time round.

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It's been a busy week for climate skeptics and myth debunkers alike. David Rose's Mail on Sunday  article, in which he rehashed an old and widely discredited claim that "global warming stopped 16 years ago", very quickly went viral. Many  media outlets  worldwide chose to accept Rose's version of events unquestioningly. But science hit back and this week has seen a plethora of rebuttals of Rose's claims, including one  we published  on Monday. Here's our pick of the best of the rest.

Rose's version of events

In his article, Rose presents the graph below, which shows global atmospheric temperature data for 1997 to 2012 compared to the average for this century, and uses it to claim that it is proof that global warming has stopped.

You can read our full explanation of why Rose's claim is unjustified  here. But to summarise, the period in question shows  reduced warming  compared to previous decades. Such periods are not unusual in the historical record, however. Natural variability in earth's climate, due to things like the  El Niňo/La Niňa cycle, also affect global temperature. This means you have to look at the trend over a much longer time period than 16 years. Just looking at land surface temperature also ignores all the other ways we know the planet is warming, like melting ice sheets and absorption of heat  by the oceans.

Six articles explain why different aspects of Rose's article are unfounded:

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