Analysis

New study: 99% of Mount Everest’s glaciers could be gone by 2100

  • 27 May 2015, 08:00
  • Robert McSweeney
Dudh Kosi basin

Dudh Kosi basin | Patrick Wagnon

A region of the Himalayan mountain range, home to the iconic peak of Mount Everest, could be almost completely free of glaciers by the end of the century, a new study shows.

And the findings may illustrate what could happen to glaciers across eastern and southern parts of the Himalayas, the lead author tells Carbon Brief.

Mount Everest

The Dudh Koshi river basin sits in central Nepal. It's home to some of the world's tallest mountains, including Mount Everest itself, and is one of the most popular climbing and tourist destinations in Nepal.

Around 410 square kilometers of the area is covered in glaciers, huge rivers of ice formed from snow compacted over many years. In this part of Nepal, these are monsoon-type glaciers, which both lose ice through melting and gain it through snowfall during the summer monsoon season.

In a new study, published in  The Cryosphere, researchers use past measurements of the glaciers to develop a model to analyse how they have changed and could change in the future as global temperatures rise.

The graph below shows the model simulations of changes in glacier ice in the basin. Between 1961 and 2007, the volume of ice has decreased by around 16%, while the area covered by glaciers has decreased by 20%.

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Climate change could bring new hay fever misery to the UK

  • 25 May 2015, 16:00
  • Robert McSweeney
Common ragweed

Common ragweed | Nature Bureau

With spring in full swing, there's much to enjoy about sunny days and warmer temperatures. But this time of year also brings the hay fever season, when itchy eyes and sneezing beset around  18 million people in the UK.

Now a new study suggests a warming climate means worse may be on the way. The culprit is the common ragweed, an invasive species that's expanding across Europe with unpleasant consequences for hay fever sufferers.

What is ragweed?

Common ragweed is a green, leafy plant that is native to North America but has taken root in Europe, Australia, East Asia and South America since the end of the 19th century.

Ragweed typically grows around farmland and construction sites, and along riverbanks and railway embankments. It flowers through the summer and into the autumn and produces large amounts of pollen, which can be carried by the wind from one country to another.

The UK is currently a bit too cold for the plant to flourish. And while ragweed pollen is blown over from Europe, it's rarely in high enough quantities to cause hay fever symptoms.

But that could be set to change. New research, published in Nature Climate Change, estimates the amount of ragweed pollen in the air across Europe will be four times higher by 2050. And it could even be as much as 12 times higher, the study shows.

This means a lot more ragweed pollen reaching the UK, the researchers say.

The study is part of a Europe-wide project on how changes in climate, land use and air pollution will affect the spread of pollen and its impact on human health.

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Satellites reveal rapid acceleration of Antarctic glacier ice loss

  • 21 May 2015, 19:00
  • Robert McSweeney
Antarctic research vessel

Antarctic research vessel | J.L. Bamber

Thinning of glaciers in one of the most vulnerable parts of Antarctica has accelerated at a "remarkable rate" since 2009, a new study finds.

Stable through the 2000s, the glaciers began losing large quantities of ice within just a year or two, the lead author tells Carbon Brief.

The study shows the surprising speed with which Antarctica's glaciers can react to rising ocean temperatures, and without warning, he says.

Remarkable acceleration

Glaciers are huge rivers of ice that ooze their way over land, powered by gravity and their own sheer weight. They accumulate ice from snowfall and lose it through melting.

In the new study, published today in  Science, researchers analysed changes to glaciers on the Southern Antarctic Peninsula in the last decade and a half.

For most of the 2000s, satellite data shows the glaciers lost about as much ice as they gained, meaning they stayed roughly stable. But around 2009 there was "a remarkable rate of acceleration" in ice loss, the study says.

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Scientists warn against premature predictions of a "substantial" El Niño

  • 20 May 2015, 17:00
  • Roz Pidcock

It's too early to tell if the El Niño brewing in the Pacific will be a big event or how serious its impacts might be, scientists warned today.

Speaking at a press conference in London, scientists said they can't rule out an  El Niño as large as the one in 1997/8 - which raised global temperature by more than half a degree - but it's looking unlikely.

There's even a slight chance this year's event could be a false alarm, say the scientists. But their best current guess is that we should expect a "moderate" event in the coming months.

Forecast

Tropical Pacific surface waters are warmer than average for this time of year, and have been for several months - a sure sign that El Niño is  underway.

The  latest forecast from the US National Oceanic and Atmospheric Administration (NOAA) gave a strong chance of a "weak to moderate" event lasting through the Northern Hemisphere summer.

During Spring, there's still a lot of uncertainty about how El Niño could develop, and scientists are not ruling out the possibility of an event to rival the one the world experienced in the winter of 1997.

But based on current evidence, scientists are reasonably confident of a moderate strength event, Prof Adam Scaife, an expert on monthly and decadal prediction at the Met Office, told journalists today.

This would probably place this year's event somewhere between the 1997/8 and more recent 2009/10 event in terms of strength, said Scaife.

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Mountain shape a key factor in species surviving climate change

  • 20 May 2015, 08:30
  • Robert McSweeney

Himalayas | Shutterstock

One way animals and plants can cope with climate change is to relocate. Research shows some species are already shifting to higher ground or towards the poles in search of cooler climes.

But for creatures already living in mountains, the solution is not so simple. A new study of 182 high-altitude regions across the world shows how mountain shape is critical in determining whether a species will find refuge from rising temperatures further uphill.

This means the odds of survival are better for some species than others, say the authors.

Habitat range

The typical image of a mountain is a pyramid shape - a broad base that tapers to a peak. In theory, as species move upwards the habitat available to them shrinks, the paper explains.

But the study, published in Nature Climate Change, finds that over two-thirds of mountains don't follow this rule. In fact, mountains fall into one of four shapes: diamond, pyramid, inverse pyramid and hourglass, as the diagram below shows.   

Elsen & Tingley (2015) Fig1

 

Examples of four common mountain types. Colours indicate elevation, from low (blue and green) to mountaintops (yellow and orange) Source: Elsen & Tingley (2015)

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The Carbon Brief Interview: Prof Dame Julia Slingo OBE

  • 15 May 2015, 08:00
  • Leo Hickman
Prof Dame Julia Slingo

Prof Dame Julia Slingo | Carbon Brief Staff

Prof Dame Julia Slingo has been the chief scientist at the Met Office since February 2009. Before joining the Met Office, she was the director of climate research in NERC's National Centre for Atmospheric Science at the University of Reading. In 2008, she became the first female president of the Royal Meteorological Society. Earlier this month, she was made a fellow of the Royal Society.

On the 2013/14 winter flooding in the UK: "I can't give a definitive answer, but all the evidence points to the potential for climate change to have played a role."

The Met Office's new supercomputer: "It gives me more confidence in the advice we give to government, to businesses, to public on what climate change might look like."

On adaptation: "There's no point putting in flood defences that respond to mean climate change if you haven't thought of what a one-in-a-hundred-year event will look like in a warmer world."

On overinterpreting short-term temperature trends: "There are real issues with looking at too short a time period to define what we believe is climate sensitivity."

On the reliability of climate models: "Do I think our models run too warm? No, I don't."

The impact of privatising the Met Office on science: "Oh, it would fundamentally change it … We would not be able to access the observations we need for weather forecasting, let alone climate."

On transparency and open access to data: "Let's be clear, everything that's paid for by the public purse is freely and openly available."

On whether we can expect an El Niño this year: "It's very early days. We're right at the period where there's a lot of uncertainty, and we're watching it with great interest."

On whether Arctic ice melt is influencing northern hemisphere weather: "We have done a lot of research here to try and nail this question … and it's very hard to find any clear evidence yet."

On why surface temperature rise has slowed recently: "Well, I think I'm fairly convinced … there has been heat sequestered into the deeper ocean."

On dealing with personal attacks: "The way to avoid it, of course, is not to say anything. But that's not the right thing to do." 

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Antarctic Larsen-C ice shelf at risk of collapse, study warns

  • 13 May 2015, 00:01
  • Robert McSweeney

Larsen-C ice shelf | J. Schmaltz

In the past 20 years, warming temperatures have caused two ice shelves in Antarctica to collapse into the ocean. New research points to a third shelf, more than twice the size of Wales, which has thinned so much that it could now also face collapse.

The loss of the shelf would allow glaciers to flow more quickly into the ocean, pushing sea levels beyond current projections for this century, the researchers say.

Ice shelves

An ice shelf forms when a glacier on land reaches the coast and flows into the ocean. If the ocean is cold enough, the ice doesn't melt. Instead, it forms a permanently floating sheet of ice.

Ice Shelf Warming _labels

Ice shelf schematic. Source: British Antarctic Survey.

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Ice sheet melt is driving acceleration in sea level rise, study suggests

  • 11 May 2015, 16:05
  • Robert McSweeney

Melting glaciers | Shutterstock

Global sea levels are rising faster than previously thought, according to new research.

After researchers adjusted satellite sea level data to account for the slight rise and fall of Earth's land masses, they found sea level rise has accelerated in recent years.

The cause is likely to be increasing loss of ice from the Greenland and West Antarctic ice sheets, the researchers say.

Satellite data

Scientists first began using satellites to monitor global sea levels with the launch of the Topex/Poseidon mission in 1992. After two satellites from this mission, it was replaced by the Jason satellite missions in the early 2000s.

The data collected from satellites is verified against measurements taken directly from tide gauges on the sea surface. Tide gauges measure the height of the sea with reference to a fixed point, which is usually on land. As you can see from the red dots in the map below, most measurements are taken along coastlines.

Watson Et Al (2015) Fig1

Map showing tide gauges used in the study (red dots) to adjust satellite data. Black and blue dots show guages that the researchers ruled out for quality control reasons. Source: Watson et al. (2015).

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Climate change made England's record hot year in 2014 at least 13-times more likely

  • 01 May 2015, 10:30
  • Robert McSweeney

Evening sunset | Shutterstock

Last year was England's hottest year since records began over three and a half centuries ago, the Met Office revealed in January. Now a new study shows that this record-breaking year was at least 13-times more likely because of human-caused climate change.

And as our influence on the climate becomes more evident in the future, we can expect the chances of record hot years to increase further, the lead author tells Carbon Brief.

Hottest year

Stretching back over three and a half centuries, the Central England Temperature (CET) record is the longest instrumental record in the world. It provides daily and monthly temperatures averaged over a roughly-triangular area between London, Bristol and Lancashire.

With an average temperature of 10.93C, 2014 topped the list as England's hottest year, just edging ahead of the 10.87C recorded in 2006. Since the difference between the two numbers is smaller than the error associated with these types of measurements, scientists can't be absolutely sure that 2014 was the warmest year - but it's the most likely to be.

Cet -record -2014

40 highest-ranked years from warmest to coldest of the Central England Temperature record. Colours show the time period of each year, and height of the bar shows the uncertainty in the measurement. Source: Dr Ed Hawkins of Reading University.  Source: Dr Ed Hawkins of Reading University.

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Climate change threatens one in six species with extinction, study finds

  • 30 Apr 2015, 19:00
  • Robert McSweeney

American Pika | Shutterstock

The risk of Earth's species becoming extinct will accelerate as global temperatures rise, new research shows.

After reviewing more than one hundred scientific papers, the study finds as many as 16% of plant and animal species on land and in the oceans would be under threat with four degrees of warming.

Climate change could even overtake habitat loss and degradation as the main cause of extinctions, the lead author tells Carbon Brief.

Extinction risk

The rate at which plants and animals are becoming extinct is now a thousand times higher than before humans inhabited the Earth.

Habitat loss is the principal cause of extinctions, as forests are cleared and urban areas expand. But a new study, published in Science, suggests that climate change could soon become a key threat to species around the world.

A warmer world could have many different impacts on plants and animals, not least by pushing temperatures beyond species' physical tolerance. Shifting seasons can affect breeding patterns, and hot days may mean animals have less energy to search for food.

Changes to rainfall patterns may affect availability of water and freshwater habitats. These changes could conspire to influence how much food a species can access, and what predators and diseases it is exposed to.

The combination of habitat loss and climate change is likely to intensify their individual impacts on different species, Prof Joshua Lawler, who wasn't involved in the study but who is an author of the latest Intergovernmental Panel on Climate Change (IPCC) report, tells Carbon Brief:

"[H]abitat loss and fragmentation will make it harder for species to move to suitable climates, and climate change will drive human migrations and shifts in the distribution of cultivated lands which will, in turn, reduce habitat for species."

In the new study, Prof Mark Urban from the University of Connecticut aggregates the results of 131 studies on extinction risk to give a global picture of the risks posed by climate change.

Exponential rise

The current target for international climate policy is to limit global temperature rise to 2C above pre-industrial temperatures. Even with this level of warming, we can expect to lose around 5% of species, the study finds.

But as you can see in the graph below, the predicted extinction percentage increases as global temperatures rise beyond the 2C limit.

Urban (2015) Fig2

Predicted extinction rates from climate change rise with global temperature. Blue bubbles show individual studies, and their size shows how many species the study assessed. Source: Urban (  2015).

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