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Bad tidings: Carbon Brief’s best climate change reads of 2013

  • 30 Dec 2013, 10:00
  • Ros Donald

Credit: Abhi Sharma

Melting ice caps, rising sea levels, energy dilemmas ... don't they say Christmas to you? Ignore the umpteenth series of Downton Abbey and curl up with Carbon Brief's pick of the best energy and climate reads from 2013. From the big reports to the best writing, our staff recommend their standout reads of the year.

Climate: The IPCC Working Group 1 report

In case you've been living under a stone for the past few months, you'll know the Intergovernmental Panel on Climate Change released its Working Group One report this autumn. The report concluded that scientists are more sure than ever- 95 per cent certain - that humans are causing extra warming. The oceans, land and atmosphere are getting warmer, snow and ice is melting and sea levels are rising.

Communicating the science

As not many people are likely to read the whole tome, communicating the report has been a key preoccupation for those of us who are interested in that sort of thing. The IPCC demonstrated laudable self-awareness in producing a 10-minute film running through the main points in the report.

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Hockey sticks to huge methane burps: Five papers that shaped climate science in 2013

  • 27 Dec 2013, 11:00
  • Roz Pidcock

There's no doubt, 2013 was a busy year in climate science. As well as a bumper new climate report from the UN's official climate assessment body - the Intergovernmental Panel on Climate Change (IPCC) - a few bits of research caused quite a stir on their own.

We've cast our collective Carbon Brief mind back over the year to find the five science papers that had everybody talking.

1.  What hockey stick graphs tell us about recent climate change

Using fossils, corals, ice cores and tree rings, a study in the journal Science in March became the first to take a 11,300-year peek back into earth's temperature history.

Shaun Marcott and colleagues  showed global temperature rose faster in the past century than it has since the end of the last ice age, more than 11,000 years ago.

The story piqued the interest of  The Times The Independent,  The Daily Mail and  The Evening Standard. And as an extension of Michael Mann's iconic "hockey stick" graph, the paper attracted a good deal of attention from climate skeptic corners too.

Global temperature reconstructed for the past 11,300 years by Marcott et al. (purple line) and for the past 2,000 years by Mann et al. (grey lines) Source:  Skeptical Science

Marcott, S. A. et al., (2013) A Reconstruction of Regional and Global Temperature for the Past 11,300 Years. Science, DOI:10.1126/science.1228026

2.World's oceans are getting warmer, faster  

study led by UK researcher Magdalena Balmaseda highlighted why its important not to overlook the oceans when thinking about climate change.

Publishing in the journal Geophysical Research Letters, the authors showed just how much the oceans have warmed in the past 50 years - and that the pace accelerated sharply after about 2000.

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Predicting the future: The challenge of regional climate projection

  • 24 Dec 2013, 13:40
  • Professor Mat Collins

Niels Bohr, the famous Danish Physicist, once remarked 'Prediction is very difficult, especially when it's about the future'.

This quote is sometimes used to suggest that making predictions of future climate change is an impossible task. But, of course, we can predict the future. Meteorological services around the world do it every day, with ever increasing accuracy.

To predict future changes in climate, scientists use climate models. We feed in assumptions about future levels of greenhouses gases, then run the models forward in time and diagnose the output. We usually speak of "projections" to indicate that our predictions are not definitive, they are conditional on those economic, social and technological assumptions about future greenhouse gas levels.

All of this activity takes place in modelling centres around the world. A recent revolution in the field has been to collect the output from experiments performed at different modelling centres into a central repository, making the data available to a larger community of climate researchers. This is called the Coupled Model Intercomparison Project (CMIP).

A changing climate

With a changing climate, there's demand for information about the changes we can expect at scales that might affect particular populations, ecosystems and economies. So how confident can we be about changes projected for a given region?

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AGU 101: A guide to the US’s biggest geoscience conference

  • 20 Dec 2013, 11:45
  • Guest post by Dr Mark Brandon

Rebecca Morelle

Two giant, week-long, geoscience meetings mark the calendar. In Europe the European Geoscience Union (EGU) General Assembly is around Easter, and in North America just before Christmas is the American Geophysical Union (AGU) Fall Meeting. These two conferences are huge, with 10-20,000 scientists gathering to talk about their work. But how does such a vast science meeting work for the participants? It's all about "sessions", posters and talks.

Last week was the AGU Fall meeting and I was one of probably hundreds of UK geoscientists who made the journey to San Francisco. Big meetings create media interest and the BBC sent two science journalists to write stories.

Their output captures part of the range of science at the meeting - but it's worth noting  they highlighted only about 20 stories from the many thousands presented. My favourites were from Jonathan Amos on the new "coldest place on earth" and the methane seas of Titan, and I loved Rebecca Morell's stories on "missing earthquakes" from the historical record and water spouts on Europa.

Any member of AGU can propose a session subject and title usually by April in the year of the meeting. The organisation committee selects sessions to create  a varied programme  ( PDF  here ) - but given that there are around 1500 sessions over the week you would have to be hard pushed to seriously suggest there is some sort of "gatekeeping" going on with what gets discussed.

When the session lists are published online in early summer, any member of AGU can submit an abstract describing an element of science that fits in a particular session. Then it's down to the conveners of the session to choose abstracts that they would like to see as a talk, or a poster showcased in AGU's gargantuan poster room.

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Geoengineering's limitations: technical, social, and ethical

  • 19 Dec 2013, 09:30
  • Mat Hope

Credit: Satoru Kikuchi

As politicians edge towards agreeing a new international climate deal in 2015, policymakers are increasingly considering a broad sweep of policy options to reduce global greenhouse gas emissions - including techniques to deliberately 'engineer' the climate.

In a special edition of the journal Climatic Change, researchers have turned their attention to addressing some fundamental issues surrounding the future of geoengineering.

What is 'geoengineering'?

The journal broadly defines  two types of geoengineering: carbon drawdown and removal (CDR) and solar radiation management (SRM). In theory, both techniques could help address some, but not all, of the impacts of climate change.

CDR involves drawing greenhouse gas emissions out of the atmosphere and locking them away. For example, carbon capture and storage (CCS) technology - which can be fitted to power plants to reduce their emissisons - is a type of CDR. SRM techniques are a bit different. They involve reflecting sunlight away from the earth's surface in various ways in an attempt to control the amount of warming that occurs, without actually affecting emissions. This can be done by creating clouds or putting  mirrors in space to reflect sunlight, for instance.

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Could Arctic summers be sea ice-free in three years’ time?

  • 12 Dec 2013, 12:41
  • Roz Pidcock

Climate change is causing a long-term decline in Arctic sea ice, and scientists expect the Arctic Ocean to be largely ice-free in summer at some point this century.

But is that broad prediction too complacent? This week, the Guardian claimed scientists working for the US Navy believe summer sea ice could disappear as soon as 2016, based on the results of a sophisticated new computer model.

But having looked at the research, it turns out the 2016 prediction is from an older, simpler model, and isn't the US Navy prediction of what's going to happen in the Arctic. It's also much sooner than most polar scientists would suggest.

An ice-free prospect

Arctic sea ice is declining by nearly four per cent per decade, according to the  latest report from the Intergovernmental Panel on Climate Change (IPCC). The loss is particularly noticeable at the end of summer, when the ice reaches a seasonal low.

Arctic _sea _ice _summer

Average extent of Arctic sea ice in summer (colours represent different datasets). Source: IPCC 5th Assessment Report,  Summary for Policymakers (p8)

The change has  wide-reaching consequences, so when it might happen is an important question.

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The rest of Europe lags behind the UK in preparing cities for climate change

  • 27 Nov 2013, 11:10
  • Roz Pidcock

The UK is leading Europe in terms of the number of cities that have climate change mitigation or adaptation plans, according to a new study. But one in three European cities has no plan whatsoever in place for coping with a changing climate.

Major players

Global temperatures have risen by  0.85 degrees over the industrial era - and cities have had a large part to play in that warming. Research suggests cities are currently responsible for more than  70 per cent of global carbon dioxide emissions.

Cities are also considered at high risk from climate change impacts, such as extreme weather and flooding, because they cram a lot of people into a small area, support vital infrastructure and contain valuable commercial assets.

But a new study suggests more than a third of European cities are unprepared for climate change, with neither a plan in place to reduce emissions nor to cope with the  expected impacts.

Where did the story come from?

The findings come from a new paper just published in the journal  Climatic Change. The large team of 12 authors hail from the US, the Netherlands, the UK, Spain, Ireland, France, Sweden, Estonia and Italy.

Lead author,  Dr Diana Reckien, carried out the research while a visiting scholar at the Centre for Environmental Decisions, part of Colombia University in New York.

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Research brief: New study suggests warming set to continue even if emissions drop to zero

  • 26 Nov 2013, 11:35
  • Roz Pidcock

Even if carbon emissions miraculously ground to a halt overnight, global temperature would keep rising for centuries. At least, that's the conclusion from a new study, which piqued the  Telegraph's interest in recent days. With the latest UN climate report saying otherwise, we take a closer look at what emissions cuts - fast and slow - might mean future temperatures.

Halting emissions

In its latest climate  report, the Intergovernmental Panel on Climate Change (IPCC) looked at what would happen if carbon dioxide emissions could be suddenly stopped. It concluded that temperatures would decrease only very slowly, if at all.

Now a new paper challenges those conclusions, saying we're likely to see temperatures continue to rise hundreds of years, even after emissions come to a halt.

The authors say this "illustrates how difficult it may be to reverse climate change - we stop the emissions but still get an increase in the global mean temperature".

Where did the story come from?

The new research was carried out by a group of scientists at Princeton University and the National Oceanic and Atmospheric Administration (NOAA) in the United States, although lead author Thomas Frölicher is now part of the Swiss Federal Institute of Technology in Zurich.

Their research was published on Sunday in the journal  Nature Climate Change and covered in yesterday's  Telegraph.

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IPCC sea level rise projection probably too low, says expert survey

  • 22 Nov 2013, 18:30
  • Freya Roberts and Roz Pidcock

A new survey of expert opinion suggests 21st century sea level rise might be higher than the latest UN climate report projects. More than two thirds of the researchers interviewed for the study said higher and faster rises are possible - implying the report's estimates could be too conservative.

Upper limit underestimated

The most comprehensive projections on sea level rise are those contained in the  report from Intergovernmental Panel on Climate Change (IPCC). The IPCC evaluates evidence from all the published literature and combines the estimates into a single set of projections.

In its most recent report, the IPCC predicted sea levels are likely to rise by between 0.28m and 0.98m by 2100 - a range encompassing both its highest and lowest emissions scenarios.

But according to a new survey of sea level experts, that range might be an underestimate. Scientists from the Potsdam Institute of Climate Impact Research (PIK) asked 90 researchers from 18 different countries for their expert opinion on future sea level rise.

Two thirds of those questioned said they thought sea levels could rise higher than the IPCC's upper estimate for the end of the century.

When asked what they thought the likely range of sea level rise would be under a low emissions scenario, the experts came up with similar estimates to the IPCC.

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No time for delay in cutting greenhouse gas emissions, say IPCC scientists

  • 22 Nov 2013, 13:30
  • Roz Pidcock

As the end of the second week of climate talks draws nigh in Warsaw, a group of high profile scientists have laid out what needs to happen to stay below two degrees of global warming. The answer? Deep greenhouse gas cuts, and no more excuses for delay.

A matter of urgency

In its latest  report, the Intergovernmental Panel on Climate Change (IPCC) said limiting global warming requires "substantial and sustained" cuts in greenhouse gas emissions.

In a  new letter in Nature Climate Change, co-chair of the IPCC Thomas Stocker and Myles Allen from Oxford University consider two arguments used to suggest emission cuts can be delayed.

The first is that scientists have slightly lowered their assessment of how big the warming effect of carbon dioxide is on the planet - known as the climate sensitivity.

The other argument is that reducing emissions of pollutants like black carbon and methane is a more achievable way to limit total warming, instead of tackling carbon dioxide emissions.

The authors examine both arguments, concluding neither "buys time" to delay efforts to reduce carbon dioxide. Delaying emissions cuts now will make it harder to reduce warming in the long run, they say.

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