UK flooding pushes public acceptance of manmade climate change to five-year high

  • 29 Jan 2015, 00:01
  • Robert McSweeney

Berkshire floods 2014 | Shutterstock

There is growing public acceptance of the human contribution to climate change, according to a new study published today. The latest results from a national survey show public agreement that humans are causing climate change is at its highest level for 5 years.

The researchers also find that those affected by the UK winter floods in 2013-14 were significantly more likely to be concerned about climate change than those that weren't affected.

Public acceptance

A year on from the major winter flooding in the UK, the new study led by Cardiff University sheds new light on public perception of climate change. Researchers interviewed 1,002 people across the country about their views on climate change and the floods.

The results of the survey show almost nine in 10 respondents said the world's climate is changing (88 per cent), and more than eight in 10 said human activity was at least partly the cause (84 per cent). This represents the highest level of acceptance that the climate is changing since surveys began asking the question in 2005. More than a third (36 per cent) said that climate change is mainly or entirely caused by humans, which is the most agreement on the human impact on climate change since the question was first included in comparative surveys in 2010.

Capstick Et Al (2015) Is The Climate Changing

Responses from this and previous surveys to the question 'As far as you know, do you personally think the world's climate is changing?'. Source: Capstick et al. (2015).

Capstick Et Al (2015) Causes Of Climate Change

Responses from this and previous surveys to the question 'Thinking of the causes of climate change, which best described your opinion?'. Source: Capstick et al. (2015).

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Warming Arctic to break down barriers between Atlantic and Pacific fish, study finds

  • 27 Jan 2015, 16:23
  • Robert McSweeney

Fishing off Greenland | Shutterstock

For millions of years, fish species in the Pacific and Atlantic oceans have stuck resolutely to where they belong, kept from venturing between oceans by the cold water of the Arctic.

But new research suggests a warming Arctic could soon see fish putting aside their differences and bridging this chilly divide. And this could have implications for native species and commercial fisheries, the researchers say.

A natural barrier

For most of the last 2.6 million years, the cold temperatures and low nutrient levels of the Arctic have deterred fish species from crossing between the Pacific and Atlantic oceans.

The cold conditions mean at present only 135 of more than 800 known fish species are found in latitudes north of where the UK sits, in either the Atlantic or Pacific Ocean.

But a new study, published in Nature Climate Change, finds that with Arctic temperatures increasing almost twice as fast as the global average, this natural barrier is set to weaken.

Melting sea ice will mean ocean currents can carry warmer water and nutrients into Arctic water, taking fish further north and potentially allowing them to mix between oceans.

'Rapid explosion in fish biodiversity'

The researchers use computer models to forecast future ocean conditions such as surface temperatures, salinity, and currents, and project how the distribution of different fish species could respond to climate change.

They analysed how suitable the Arctic seas would be for over 500 fish species during this century if greenhouse gas emissions continue at current rates.

The maps below show that many species will gradually progress north, eventually reaching the northern coasts of Canada and Russia, where fish from each ocean can mix. Their modelling shows that by 2100, 44 species could enter the Atlantic from the Pacific, with 41 species potentially crossing back the other way.

Wisz Et Al . (2015) Fig 1 Fish Interchange

Projected number of fish species in high latitudes under business-as-usual greenhouse gas emissions. Results shown for 2015, 2050 and 2100. The dark blue show areas with the most species present. Source: Wisz et al. (2015).

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Expect twice as many extreme La Niña events under climate change, study warns

  • 26 Jan 2015, 16:00
  • Robert McSweeney

2011 La Nina in Bangkok | Shutterstock

The Pacific weather phenomenon known as El Niño or 'The Little Boy' is regularly in the news. Scientists keep a close eye on its status as events can cause devastating extreme weather around the world.

But El Niño has a lesser-known sister, La Niña, which also has a dramatic impact on global weather. Now a new study suggests that we could see La Niña events occurring twice as often as the climate warms.

The lesser-known sibling

Every five years or so, weakening trade winds causes a shift to warmer than normal ocean temperatures in the eastern equatorial Pacific Ocean, a phenomena known as El Niño.

La Niña, or 'The Little Girl', is El Niño's cold water counterpart. During La Niña events the trade winds strengthen, and the central and eastern Pacific Ocean becomes even colder than normal. La Niñas are known to bring drought to the southwestern US, floods to Central America, and hurricanes to the Atlantic Ocean.

Together, the warm and cold events form the El Niño-Southern Oscillation (ENSO), and cause most of the fluctuations in global weather we see from one year to the next.

Understanding how extreme La Niña will change as global temperatures rise has challenged scientists for the past three decades. A new paper, published in Nature Climate Change, suggests that extreme La Niña events will occur almost twice as often in the twenty-first century than they did in the twentieth.

La -nina

Credit: Rosamund Pearce, Carbon Brief

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DNA: How it's helping scientists understand species’ adaptation to climate change

  • 21 Jan 2015, 17:00
  • Robert McSweeney

DNA molecules | Shutterstock

How species respond to climate change could well determine their chances of survival. A new paper describes how scientists are finding new ways to understand how plants and creatures adapt to climate change - by digging deep into their DNA.

The methods are allowing scientists to measure responses to climate change at a greater scale than ever before, the study's lead author tells Carbon Brief.

DNA sequencing

DNA holds all the genetic information that controls how an organism will develop and function. In humans, it dictates physical traits such as height and  eye colour.

DNA sequencing is the way scientists identify which genes control particular traits in a species. But as organisms may have millions or billions of pieces of DNA, sequencing can be a lengthy process.

The new paper, published in BioScience journal, describes how a technology called 'next-generation DNA sequencing' (NGS) allows scientists to analyse millions of pieces of DNA at the same time. This dramatically reduces how much time and money sequencing takes, the paper says.

Lead author, Prof Jonathon Stillman, uses an analogy of analysing a haystack to describe NGS. Using traditional methods you would need to pick out a few straws and use those to try understand the whole haystack, he says, but with NGS you can look at every straw of hay individually.

Move, adapt or die

So what are scientists doing with all this genetic information?

There are three ways a species can respond to changing conditions: move, adapt or die. While it is relatively easy to measure if a species is dying out, monitoring how it moves or adapts is more difficult. This is because scientists need to be able to study how its DNA or physical characteristics are changing.

Scientists use the data they gather from NGS to see where species migrate and which physical traits they're developing to survive. One  study, for example, uses NGS to track how the habitat of three species of giant clams expanded as sea levels rose after the last ice age. And a  study also published this week shows how polar bears have gradually migrated north in search of more year-round sea ice.

There's more than one way that a species can adapt, the study says, and NGS can help with both.

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How the Met Office forecast a hot 2014 and why it thinks 2015 may be even hotter

  • 21 Jan 2015, 14:30
  • Simon Evans

When the Met Office publishes its 2014 global temperature figure on Monday, a group of scientists will be quietly congratulating themselves for having correctly forecast the outcome.

Just over a year ago in December 2013 the Met Office forecast that 2014's temperature would be 0.57 degrees Celsius above the long-term average, a statistical tie for the warmest year on record. Its forecast looks set to be right on the money, agreeing with actual temperatures to within a few hundredths of a degree.

The Met Office has been predicting global temperatures one year in advance since 1999, and it turns out its scientists are rather good at this.

Carbon Brief spoke to the Met Office's Professor Chris Folland to find out how his team forecast the hot year for 2014 and why they are forecasting that 2015 could be even hotter.

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Melting glaciers set to release more organic carbon as temperatures climb

  • 19 Jan 2015, 17:00
  • Robert McSweeney

Melting glacier | Shutterstock

Melting ice may affect more than sea levels, according to new research. As the earth warms, more of the carbon locked up in glaciers and ice sheets will be released into surrounding rivers and oceans.

This means that, as well as pushing up sea levels, melting ice could have unknown impacts on marine life.

Carbon release to increase by half

Glaciers and ice sheets cover around 11 per cent of Earth's land surface and hold around 70 per cent of its freshwater. These giant stores of ice also hold  organic carbon. Carbon accumulates in new snow and ice, and is released as the glacier melts.

A new study, published today in Nature Geoscience, finds the release of this carbon will speed up as the Earth warms due to climate change.

Around 15 million tonnes of extra organic carbon will be lost from melting glaciers over the next 35 years in the form of tiny dissolved particles, the researchers say. Ice also contains larger 'particulate' carbon, which are like bits of sediment that a river carries.

This extra organic carbon is 47 per cent more than we could expect without climate change, and equivalent to around half of what the Amazon river carries each year, the researchers say. 

Organic carbon provides food for tiny organisms at the bottom of the food web. So the extra carbon flowing into rivers and oceans may affect the plants and animals that live around the ice sheets, the researchers say. Adding organic carbon can also affect the chemistry of water, by making it more acidic, for example.

A research first

The research is the first to estimate the total amount of organic carbon held in ice across the world. Researchers collected measurements of organic carbon concentrations from more than 300 samples of glacier and ice sheets in four continents, as the map below shows.  

Hood Et Al (2015) Fig 1 Glacier DOC

Scientists collected organic carbon samples across four continents. Photos show examples of a) Alaska, b) Tibet, c) Dry Valley glaciers in Antarctica, and d) the Greenland Ice Sheet. Source: Hood et al. (2015)

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Scientists react: 2014 confirmed as hottest year on record

  • 16 Jan 2015, 17:13
  • Carbon Brief staff

Land & ocean percentiles 2014 | NOAA

NASA and the US National Oceanic and Atmospheric Administration (NOAA) have confirmed 2014 was the warmest year since records began in 1880. 

The 10 warmest years in the instrumental record, with the exception of 1998, have now occurred since 2000.

Carbon Brief rounds up the reaction from scientists…

Prof Jonathan Overpeck, co-director of the University of Arizona's Institute of the Environment,  said in USA Today:

"Humans are literally cooking their planet...It just shows that human emissions of greenhouse gases, mainly from the burning of fossil fuels, are taking over the Earth's climate system. The data are clear. The Earth is warming and humans are causing the bulk of this warming."

Overpeck said in the Huffington post:

"Perhaps more important than the global temperature story are the impacts of record regional heat. In places like California, the Southwest U.S. more generally, Australia and parts of Brazil, record heat is exacerbating drought and leading to more stress on our water supplies and forests."

"With continued global warming, we're going to see more and more of these unprecedented regional conditions, and with them will come more and more costs to humans and the things they value. 2014 shows that humans are indeed cooking their planet as they continue to combust fossil fuels."

Dr Radley Horton, a scientist from Columbia University, said in USA Today:

"What we have known for decades is that increasing greenhouse gas concentrations - due to human activities - have stacked the deck dramatically towards more record warm years, and fewer record cold years."

Prof Stefan Rahmstorf, head of earth system analysis at the Potsdam Institute for Climate Impact Research in Germany, said in the New York Times:

"Obviously, a single year, even if it is a record, cannot tell us much about climate trends. However, the fact that the warmest years on record are 2014, 2010 and 2005 clearly indicates that global warming has not 'stopped in 1998', as some like to falsely claim."

Dr Gavin Schmidt, director of Nasa's Goddard Institute of Space Studies, said in the New York Times:

"Why do we keep getting so many record-warm years? It's because the planet is warming. The basic issue is the long-term trend, and it is not going away."

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Explainer: How do scientists measure global temperature?

  • 16 Jan 2015, 11:40
  • Roz Pidcock

Every year around this time, there's a flurry of activity in the world's major meteorological agencies as they prepare to release official global temperature figures for the previous year.

This year, there's particular interest as it looks likely 2014 will be the hottest year on record.

First out the blocks with the official data was the Japan Meteorological Agency (JMA). Earlier this month, it confirmed 2014 had  taken the top spot with global temperatures 0.27 degrees Celsius above the long-term average. Today, it's the turn of NASA and the US National Oceanic and Atmospheric Administration, with the UK Met Office following suit next week.

Why so many records? While global temperature is a simple enough idea, measuring it is harder than you might think. We take a look at what goes into taking Earth's temperature.

The basics

To get a complete picture of Earth's temperature, scientists combine measurements from the air above land and the ocean surface collected by ships, buoys and sometimes satellites, too.

The temperature at each land and ocean station is compared daily to what is 'normal' for that location and time, typically the long-term average over a 30-year period. The differences are called an 'anomalies' and they help scientists evaluate how temperature is changing over time.

A 'positive' anomaly means the temperature is warmer than the long-term average, a 'negative' anomaly means it's cooler.

Daily anomalies are averaged together over a whole month. These are, in turn, used to work out temperature anomalies from season-to-season and year-to-year.


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Scientists issue stark warning as Earth passes into ‘danger zone’

  • 15 Jan 2015, 19:00
  • Robert McSweeney, Rosamund Pearce & Roz Pidcock

Human activity over the past century and a half has pushed the Earth into critical mode, say scientists. New research published today finds four out of nine 'planetary boundaries' have now been crossed. Biodiversity loss, fertiliser use, climate change and land use have all exceeded the point at which the risk of sliding into a "much less hospitable" world becomes high.

Passing any one of the nine critical boundaries risks disrupting the complex and delicate interactions that exist on Earth between the land, ocean, atmosphere, ice sheets and people, says the team of 18 researchers.

An early warning

The concept of planetary boundaries is to identify how much humans can develop and use the Earth's resources while staying safely within limits of what the planet can take.

In 2009, a collaboration of several top research institutions identified a set of nine processes that regulate the land, ocean and atmosphere systems on Earth. For each process they identified a boundary beyond which humans would cause "unacceptable environmental change".

You can see the boundaries in the figure below, which also shows the current status of each one.

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Global sea levels rising faster than previously thought, study shows

  • 14 Jan 2015, 18:00
  • Robert McSweeney

Sea level rise | Shutterstock

Scientists have a good idea of the different factors that contribute to sea level rise. But historical measurements of sea level change from the twentieth century don't seem to match up to sum of all these individual factors.

A new paper, published in Nature, offers an explanation to this puzzle. The study finds that the amount of sea level rise during the last century is lower than scientists previously thought.

But the implication of this finding is that the acceleration in sea level rise seen in recent decades is more rapid than scientists thought, the study says. And the researchers say that melting ice sheets are the reason.

Balancing the books

Several different components contribute to rising sea levels rise, including water expanding as it warms, melting glaciers and ice sheets, and changes to how much water is stored on land.

Scientists calculate global sea levels in two ways: by taking direct measurements of sea levels, and by using models and observations to estimate the contribution of each of these components and then adding them together.

But this has presented scientists with a problem: the figures from the two methods don't quite match for the twentieth century. In the latest  Assessment Report from the Intergovernmental Panel on Climate Change (IPCC), observed sea level rise is estimated at 1.5mm per year from 1900 to 1990, but only 1mm per year when researchers calculate it by adding together the individual contributions.

Scientists have sought the answer to this  enigma, and the new paper offers an answer. It says that there is no discrepancy, because historical observed measurements were overestimating sea level rise for much of the last century.

By eliminating the difference between the two types of measurements, lead author Dr Carling Hay at Harvard University tells Carbon Brief, they are able to close the sea level budget:

"To put it another way: the books are balanced."


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