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Climate costs ‘may prove much higher’

April 16, 2014 in Atlantic Multidecadal Oscillation, Economy, Greenhouse Gases, Methane, Permafrost, Warming slowdown

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A meat store built in the melting  permafrost of Herschel Island in the Arctic Ocean Image: Ansgar Walk via Wikimedia Commons

A meat store built in the melting permafrost of Herschel Island in the Arctic Ocean
Image: Ansgar Walk via Wikimedia Commons

By Tim Radford

There may be a higher price for our descendants to pay for the greenhouse gas build-up, researchers say, as the real costs are updated.

LONDON, 16 April – Economists and scientists may have seriously underestimated the “social cost” of carbon emissions to future generations, according to a warning in Nature.

Social cost is a calculation in US dollars of the future damage that might be done by the emission of one metric ton of carbon dioxide as greenhouse gas levels soar and climates change, sea levels rise and temperature records are broken in future decades.

How much would society save if it didn’t emit that tonne of CO2? One recent US estimate is $37. Such a measure helps civil servants, businessmen and ministers to calculate the impact of steps that might be taken.

On the other hand, say Richard Revesz of New York University School of Law and US and Swedish colleagues, assumptions of cost per tonne – and these range from $12 to $64 according to various calculations – are based on models that need to be improved and extended. The cost of climate change could be higher, for four reasons.

Flawed assumptions

The impact of historic temperature variation suggests societies and economies may be more vulnerable than the models predict, and in this case weather variability is more important than average weather – because crop yields are vulnerable to extremes of temperature.

Then the models omit the damage to productivity, and to the value of capital stock, because of lower growth rates: as these lower growth rates compound each other, human welfare will begin to decline. And that’s without factoring in climate-induced wars, coups or societal collapse.

Third, the models assume that the value people attach to ecosystems (and water is an ecosystem service) remains constant. But, they point out, as commodities become scarce, value increases, so the costs of ecosystem damage will rise faster than models predict.

Finally, the models assume that a constant discount rate can translate future harms into today’s dollars. But discount rates of the future may not be constant.

More warming

“What now?” they ask. “Modellers, scientists and environmental economists must continue to step outside their silos and work together to identify research gaps and modelling limitations.”

They hint at an even deeper problem: the basis of the social harm costs dates from calculations more than 20 years old, and is predicated on an average global warming of less than 3°C. Yet without mitigation, the Intergovernmental Panel on Climate Change projects a warming of 4°C by the end of the century.

“If warming continues unchecked into the twenty-second century, it could render parts of the planet effectively uninhabitable during the hottest days of summer, with consequences that would be challenging to monetize,” they write.

Economic harm may not be the only thing underestimated. Michael Mann, a meteorologist at Penn State University in the US, reports in Geophysical Research Letters that the so-called “slowdown” in global warming during this decade  could be because of an underestimate of the impact of a meteorological monster called the Atlantic Multidecadal Oscillation (AMO), an oceanographic cycle of warming and cooling that delivers natural change in northern hemisphere weather patterns.

More methane

A misreading of this cycle – probably because scientists have not known about it for long – could account for this apparent slowdown. “Some researchers in the past attributed a portion of Northern Hemispheric warming to a warm phase of the AMO,” said Professor Mann.

“The true AMO signal, instead, appears likely to have been in a cooling phase in recent decades, offsetting some of the anthropogenic warming temporarily.” And when the rate of warming rises again, there’s yet more alarming evidence of possible acceleration, according to new research.

The thawing of the Arctic sea ice is also accompanied by a softening and warming of the Arctic permafrost, and changes in the chemistry of the preserved peat, that could release ever larger amounts of methane. Methane is a greenhouse gas, present in smaller quantities than carbon dioxide, but 34 times more potent as a warming agent over 100 years.

If the permafrost melts entirely, that would put five times the present levels of carbon into the atmosphere, US researchers report in the journal Proceedings of the National Academy of Sciences.

“The world is getting warmer, and the additional release of gas would only add to our problems,” said Jeff Chanton of Florida State University, a co-author. – Climate News Network

Greenland’s icecap loses stability

April 13, 2014 in Arctic, Glaciers, Greenland, Ice Loss, Sea level rise, Warming

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The calving front of the Jakobshaven Glacier in western Greenland in April 2012 Image: NASA ICE via Wikimedia Commons

The calving front of the Jakobshaven Glacier in western Greenland in April 2012
Image: NASA ICE via Wikimedia Commons

By Tim Radford

Greenland is losing ice from part of its territory at an accelerating rate, suggesting that the edges of the entire ice cap may be unstable.

LONDON, 13 April – Greenland – the largest terrestrial mass of ice in the northern hemisphere – may be melting a little faster than anyone had guessed.

A region of the Greenland ice sheet that had been thought to be stable is undergoing what glaciologists call “dynamic thinning”. That is because the meltwater from the ice sheet is getting into the sea, according to a study in Nature Climate Change.

In short, Greenland’s contribution to sea level rise has been under-estimated, and oceanographers may need to think again about their projections.

Shfaqat Khan from the Technical University of Denmark and colleagues used more than 30 years of surface elevation measurements of the entire ice sheet to discover that overall loss is accelerating. Previous studies had identified melting of glaciers in the island’s south-east and north-west, but the assumption had been that the ice sheet to the north-east was stable.

Four times as fast

It was stable, at least until about 2003. Then higher air temperatures set up the process of so-called dynamic thinning. Ice sheets melt every Arctic summer, under the impact of extended sunshine, but the slush on the glaciers tends to freeze again with the return of the cold and the dark, and since under historic conditions glaciers move at the proverbial glacial pace, the loss of ice is normally very slow.

But global warming, triggered by rising levels of greenhouse gases in the atmosphere, has changed all that. Greenland’s southerly glaciers have been in retreat and one of them, Jakobshavn Isbrae, is now flowing four times faster than it did in 1997.
Now the Danish-led team has examined changes linked to the 600 kilometre-long Zachariae ice stream in the north-east.

This has retreated by about 20 kms in the last decade, whereas Jakobshavn has retreated about 35 kms in 150 years. The Zachariae stream drains around one-sixth of the Greenland ice sheet, and because warmer summers have meant significantly less sea ice in recent years, icebergs have more easily broken off and floated away, which means that the ice stream can move faster. The researchers used satellite studies to measure ice loss.

“North-east Greenland is very cold. It used to be considered the last stable part of the Greenland ice sheet,” said one of the team, Michael Bevis of Ohio State University in the US.

Deep impacts

“This study shows that ice loss in the north-east is now accelerating. So now it seems that all of the margins of the Greenland ice sheet are unstable.”

The scientists used a GPS network to calculate the loss of ice. Glacial ice presses down on the bedrock below it: when the ice melts, the bedrock rises in response to the drop in pressure, and sophisticated satellite measurements can deliver enough information to help scientists put a figure on the loss of ice.

They calculate that between April 2003 and April 2012, the region was losing ice at the rate of 10 billion tons a year.

“This implies that changes at the margin can affect the mass balance deep in the centre of the ice sheet,” said Dr Khan. Sea levels are creeping up at the rate of 3.2 mm a year. Until now, Greenland had been thought to contribute about half a mm. The real figure may be significantly higher. – Climate News Network

Corporates weigh risks, opportunities of changing climate

April 5, 2014 in Adaptation, Banking, Business, Climate risk, Economy, Europe, Resource shortages

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Swings and roundabouts: For many enterprises, climate change can have a silver lining Image: User:klip game via Wikimedia Commons

Swings and roundabouts: For many enterprises, climate change can have a silver lining
Image: User:klip game via Wikimedia Commons

By Kieran Cooke

While politicians dither about what action to take on climate change, it appears that the corporate world – in Europe at least – is taking the issue seriously and adapting its operations.

LONDON, 5 April – Europe’s company board rooms are very much alive to the risks posed by climate change – and are also busy analysing business opportunities it might provide.

That’s among the findings of a survey by the Carbon Disclosure Project (CDP), an EU-based non-profit organisation specialising in corporate environmental information, and Acclimatise, a consultancy group which gives business advice on climate change adaptation and management.

Altogether 270 of Europe’s largest companies from across 20 countries were contacted concerning their attitudes to a changing climate.

The resulting report on the survey, Climate Change Resilience in Europe, indicates that a majority of companies see climate change having a negative impact on their operations: companies identified 780 risks to their finances compared with 379 opportunities that might be available as a result of climate change.

Risk to reputations

The biggest risk foreseen is a reduction or a disruption in production capacity. “Extreme weather, drought and flooding may disrupt the supply of certain produce and products”, says one respondent, a spokesperson for the Maersk shipping and industrial conglomerate.

“This can directly affect the revenue of our supply chain but also can have a negative impact on our reputation and create a demand for more local sourcing.”

There are other expected risks: a large banking group in the Netherlands is concerned that climate change-related flooding could have an adverse impact on  its data centres.

Energy companies worry about higher temperatures disrupting the operation of power plants, while banks are concerned about their investments in companies exposed to rising sea levels.

Boost for business

“Many of the essential conditions on which businesses rely are changing, leading to increasing prices, as well as shortfalls in the quality and supply of goods and services provided to customers”, says Steven Tebbe, managing director of CDP Europe.

Yet not everyone in Europe’s corporate world is pessimistic. The report says more than 40% of companies look forward to a growing demand for their services as a result of climate change.

Construction companies in some regions of Europe might benefit from a warming climate. “Shorter and milder winters with less snow and cold can increase the productivity at some construction sites, as construction activity may experience less potential delays due to snowfall”, says Skanska AB, the Sweden-based building group.

Adaptation is key to maintaining the health of corporate finances. “Through the development of financial instruments such as catastrophe bonds, especially for regions of Africa which are particularly impacted by climate change, the financial risks posed by natural disasters and droughts can be avoided”, says Barclays, the banking group.

Staying healthy

Meanwhile Diageo, the drinks conglomerate, says that by replacing barley in its beer with less thirsty, more climate change-resistant raw materials it can gain a competitive advantage on its rivals.

“To stay competitive, business leaders must account for climate impacts and work to understand if, how and where climate risks are material to their bottom line”, says John Firth, CEO of Acclimatise.

Steven Tebbes of CDP sees a direct link between an awareness of the impact of climate change and the financial well-being of a company.

“Industry environmental transparency and performance is today a prerequisite for attracting new investments and creating new jobs – there’s increasing evidence of the links between how well a company manages environmental and climate issues and its financial performance or access to capital.” – Climate News Network

Warmer UK will face unequal death risk

April 2, 2014 in Extreme weather, Health, Heatwave, Human response, Temperature Increase, United Kingdom, Urban Heat

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Tower Bridge, the gateway to the East End of London which is likely to feel some of the strongest climate impacts Image: Myrabella / Wikimedia Commons / CC-BY-SA-3.0 & GFDL

Tower Bridge, the gateway to the East End of London which is likely to feel some of the strongest climate impacts
Image: Myrabella/Wikimedia Commons/CC-BY-SA-3.0 & GFDL

By Tim Radford

The impacts of climate change will strike unevenly, within countries as well as between them. People in poorer parts of  southern England will probably suffer most from rising heat.

LONDON, 2 April – Even in Britain, an island kingdom in a temperate zone, global warming will take its toll. And the greatest threat could be to the comfortable home counties of southern England which cluster round London.

According to research in Nature Climate Change, an average rise in summer temperatures of 2°C – and 2°C is the limit beyond which the world’s nations have agreed it would be unsafe to go – would mean around 1,550 extra deaths could be expected.

In the most vulnerable districts, the odds of dying increase by 10% for every 1°C rise in temperatures. In parts of northern England (the study was confined to England and Wales) there might be no extra deaths. But in southern England, which is often hit by extended periods of very warm weather, there was a significant rise in risk.

“It’s well known that warm weather can increase the risk of cardiovascular and respiratory deaths, especially in elderly people,” said James Bennett of Imperial College, London. “Climate change is expected to raise average temperatures and increase temperature vulnerability, so we can expect it to have effects on mortality even in countries like the UK with a temperate climate.”

As in all such forecasts, the extra deaths are notional: they are most likely to be in cases where people are already ill, or very old, and it would always be difficult to attribute any one death directly to a more than usually hot summer day. Britain, like France and other European countries, saw a sharp overall rise in mortality in 2003, when summertime temperatures soared and stayed high.

Bucking the trend

The value of such research is to help local clinics and hospitals to prepare for a greater number of emergencies. Between May and September during the decade 2001-2010, a total of 921,000 people died of cardio-respiratory causes, so the number of predicted extra deaths remains a small proportion of the normal toll.

More than half the deaths would be of people aged 85 and over, and almost two thirds would be women. The extra deaths would happen unevenly: half of all mortality would be in 95 out of 376 local authority districts in England and Wales.

The most vulnerable would be those who lived in already deprived boroughs in London such as Hackney and Tower Hamlets in the East End of the capital, and the chances of death would double on very hot days.

“The reasons for the uneven distribution of deaths in warm weather need to be studied”, said Majid Ezzati, a co-author. “We might expect people in areas that tend to be warmer would be more resilient because they adapt by installing air conditioning, for example. The results show that this isn’t the case in England and Wales.” - Climate News Network

Climate change ‘makes violence likelier’

March 31, 2014 in Adaptation, Climate risk, Conflict, El Niño, IPCC, Warming

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A UN peacekeeper chats to local youths in Darfur: Many governments now give high priority to climate change as a security issue Image: © UN Photo/Albert Gonzalez Farran

A UN peacekeeper chats to local youths in Darfur: Many governments now regard climate change as a security issue
Image: © UN Photo/Albert Gonzalez Farran

By Alex Kirby

Scientists say there is a direct link between changing climate and an increase in violence, reinforcing a key finding of the latest IPCC report.

LONDON, 31 March – US scientists say there is evidence that a warming climate is closely related to political and social instability and a higher risk of conflict.

Professor Solomon Hsiang and colleagues  described in the journal Nature in 2011 how they had investigated whether anything linked “planetary-scale climate changes with global patterns of civil conflict”.

They examined evidence of a possible link between El Niño, the periodic weather disruption off the Pacific coast of South America, which affects the weather and causes higher temperatures across much of the world, and its partner, the cooler La Niña phenomenon, with outbreaks of unrest.

After analysing data from 1950 to 2004, they found that “the probability of new civil conflicts arising throughout the tropics doubles during El Niño years relative to La Niña years.”

They wrote: “This result, which indicates that ENSO may have had a role in 21% of all civil conflicts since 1950, is the first demonstration that the stability of modern societies relates strongly to the global climate” (ENSO, the El Niño/Southern Oscillation, is the scientific term for the cycle of alternating warmer and cooler years).

“Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence”

The work of Professor Hsiang and his colleagues predates one of the key conclusions of the latest report from the Intergovernmental Panel on Climate Change, entitled Climate Change 2014: Impacts, Adaptation, and Vulnerability, from the IPCC’s Working Group II.

This details the impacts of climate change so far, the future risks from a changing climate, and the opportunities for effective action to reduce the risks.

The report says: “Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence.” It does not however argue that there is a direct link between climate change and conflict.

Professor Hsiang’s study is cited in a report by a London-based group, the Environmental Justice Foundation, which works to protect the environment and to defend human rights. Its report, The Gathering Storm: Climate Change, Security and Conflict, says the world’s major military powers increasingly regard climate change as a significant threat.

The EJF says: “In 2012, one person every second was displaced by a climate or weather-related natural disaster.

“With millions of people forced to move each year by rapid-onset climate-related hazards and slow-onset environmental degradation, social wellbeing, human rights, economies and even state stability are at risk…at the highest level, climate change is being assessed as a risk to national security and potentially to global stability.”

It identifies several points of concern, including the shrinking of Arctic ice; competition over water resources in Central Asia; sea-level rises and small island developing states; and climate change-induced migration in the Sahel region of Africa.

“We find strong causal evidence linking climatic events to human conflict… across all major regions of the world”

The EJF report says that while climate change may not be the sole cause of conflict in future, it will play an increasingly significant role as “a threat multiplier”.

It cites a 2013 study by Professor Hsiang and others published in Science, an analysis of data drawn from archaeology, criminology, economics, geography, history, political science, and psychology.

The authors write: “We find strong causal evidence linking climatic events to human conflict across a range of spatial and temporal scales and across all major regions of the world.”

They say every 1°C rise in temperature has been estimated to cause a 14% increase of intergroup conflict and a 4% increase of interpersonal violence.

With the possibility of global average temperatures rising by 2-4°C this century, they conclude: “Amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change.”

EJF is campaigning for the recognition of climate change as not simply an environmental problem, but as a human rights issue as well. It wants the United Nations Human Rights Council (UNHRC) to establish a special rapporteur on human rights and climate change. – Climate News Network

Human activities ’caused record Oz heat’

March 24, 2014 in Australia, El Niño, Extreme weather, Forecasting, Heatwave, Ocean Warming, World Meteorological Organization

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Sanctuary for some: the summer of 2013 was a grim time for both humans and wildlife Image: By Австралиец via Wikimedia Commons

Sanctuary for some: the summer of 2013 was a grim time for both humans and wildlife
Image: By Австралиец via Wikimedia Commons

By Alex Kirby

Australia’s 2013 summer was the hottest on record only because of human influences on the climate,  meteorologists say. They report that people’s activities raised the likelihood of a record by about five times.

LONDON, 24 March – Australian researchers are in no doubt about what happened there last year. The country’s Bureau of Meteorology is a model of clarity: “2013 was Australia’s warmest year on record. Persistent and widespread warmth throughout the year led to record-breaking temperatures and several severe bushfires. Nationally-averaged rainfall was slightly below average.”

Now two Australian scientists say it is virtually certain that no records would have been broken had it not been for the influence on the climate of humans. They even put a figure on it: people, they say, raised the stakes about five times.

The World Meteorological Organization devotes a section in its report, WMO statement on the status of the global climate in 2013, to the scientists’ peer-reviewed case study, undertaken by a team at the ARC Centre of Excellence for Climate System Science at the University of Melbourne. It was adapted from an article originally published in the journal Geophysical Research Letters,

The study used nine global climate models to investigate whether changes in the probability of extreme Australian summer temperatures were due to human influences.

More frequent extremes ahead

It concluded: “Comparing climate model simulations with and without human factors shows that the record hot Australian summer of 2012/13 was about five times as likely as a result of human-induced influence on climate, and that the record hot calendar year of 2013 would have been virtually impossible without human contributions of heat-trapping gases, illustrating that some extreme events are becoming much more likely due to climate change.”

The report also strikes a warning note: “These types of extreme Australian summers become even more frequent in simulations of the future under further global warming.”.

It says last year was notable as well because it was marked by what scientists call “neutral to weak La Niña ENSO conditions”, which would normally be expected to produce cooler temperatures across Australia, not hotter. El Niño is characterized by unusually warm temperatures and La Niña by unusually cool ones in the equatorial Pacific.

Before 2013 six of the eight hottest Australian summers occurred during El Niño years. The WMO says natural ENSO variations are very unlikely to explain the record 2013 Australian heat.

“There is no standstill in global warming…The laws of physics are non-negotiable”

Introducng the report the WMO secretary-general, Michel Jarraud, said many of the extreme events of 2013 were consistent with what we would expect as a result of human-induced climate change. And he repeated his insistence that claims of a pause in climate change were mistaken.

There is no standstill in global warming. The warming of our oceans has accelerated, and at lower depths. More than 90% of the excess energy trapped by greenhouse gases is stored in the oceans.

“Levels of these greenhouse gases are at record levels, meaning that our atmosphere and oceans will continue to warm for centuries to come. The laws of physics are non-negotiable.”

The report says 13 of the 14 warmest years on record have all occurred during this century, and each of the last three decades has been warmer than the previous one, culminating with 2001-2010 as the warmest decade on record. It confirms that 2013 tied with 2007 as the sixth warmest year on record, continuing the long-term global warming trend.

Temperatures in many parts of the southern hemisphere were especially warm, and Australia was not the only country to feel the impact: Argentina had its second hottest year on record.- Climate News Network

AAAS: Climate risks irreversible change

March 18, 2014 in AAAS, Child Malnutrition, Climate risk, Coastal Threats, Extreme weather, Flooding, Food security, IPCC, Weather

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By Alex Kirby

In a highly unusual intervention in the debate over climate policy, US scientists say the evidence that the world is warming is as conclusive as that which links smoking and lung cancer.

LONDON, 18 March – The American Association for the Advancement of Science (AAAS) says there is a “small but real” chance that a warming climate will cause sudden and possibly unalterable changes to the planet.

This echoes the words used in its 2007 report by the Intergovernmental Panel on Climate Change (IPCC), which said climate change might bring “abrupt and irreversible” impacts.

A child with kwasiorkor, caused by evere protein deficiency: Child malnutrition may rise by about a fifth Image: Dr Lyle Conrad via Wikimedia Commons

A child with kwashiorkor, caused by evere protein deficiency: Child malnutrition may rise by about a fifth
Image: Dr Lyle Conrad, Centers for Disease Control and Prevention, via Wikimedia Commons

In a report, What We Know, the AAAS makes an infrequent foray into the climate debate. The report’s significance lies not in what it says, which covers familiar ground, but in who is saying it: the world’s largest general scientific body, and one of its most knowledgeable.

The AAAS says: “The evidence is overwhelming: levels of greenhouse gases in the atmosphere are rising. Temperatures are going up. Springs are arriving earlier. Ice sheets are melting. Sea level is rising. The patterns of rainfall and drought are changing. Heat waves are getting worse, as is extreme precipitation. The oceans are acidifying.

“The science linking human activities to climate change is analogous to the science linking smoking to lung and cardiovascular diseases. Physicians, cardiovascular scientists, public health experts and others all agree smoking causes cancer.

Few dissenters

“And this consensus among the health community has convinced most Americans that the health risks from smoking are real. A similar consensus now exists among climate scientists, a consensus that maintains climate change is happening, and human activity is the cause.”

The report’s headline messages are unambiguous. It says climate change is occurring here and now: “Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening.

“This agreement is documented not just by a single study, but by a converging stream of evidence over the past two decades from surveys of scientists, content analyses of peer-reviewed studies, and public statements issued by virtually every membership organization of experts in this field.

“We are at risk of pushing our climate system toward abrupt, unpredictable, and potentially irreversible changes with highly damaging impacts…Disturbingly, scientists do not know how much warming is required to trigger such changes to the climate system.

Expensive to delay

“The sooner we act, the lower the risk and cost. And there is much we can do…as emissions continue and warming increases, the risk increases”.

The AAAS says there is scarcely any precedent for the speed at which this is happening: “The rate of climate change now may be as fast as any extended warming period over the past 65 million years, and it is projected to accelerate in the coming decades.”

Historically rare extreme weather like once-in-a-century floods, droughts and heat waves could become almost annual occurrences, it says, and there could be large-scale collapses of the Antarctic and Greenland ice sheets, and of part of the Gulf Stream, loss of the Amazon rain forest, die-off of coral reefs, and mass extinctions.

The authors acknowledge that what the AAAS is doing is unusual: “As scientists, it is not our role to tell people what they should do or must believe about the rising threat of climate change.

“But we consider it to be our responsibility as professionals to ensure, to the best of our ability, that people understand what we know: human-caused climate change is happening…”

More child malnutrition

At the end of March the IPCC, the UN’s voice on climate science, is due to release a summary of the report of its Working Group II, on impacts, adaptation and vulnerability to climate change.

The London daily The Independent, which says it has seen a draft of the report’s final version, says it will spell out a prospect of “enormous strain, forcing mass migration, especially in Asia, and increasing the risk of violent conflict.”

The newspaper says the report predicts that climate change “will reduce median crop yields by 2% per decade for the rest of the century”, against a backdrop of rising demand set to increase by 14% per decade until 2050. “This will in turn push up malnutrition in children by about a fifth”, it adds.

Other predictions in the draft, The Independent says, include possible global aggregate economic losses of between 0.2 and 2.0%; more competition for fresh water; and by 2100 hundreds of millions of people affected by coastal flooding and displaced by land loss, mainly in Asia. – Climate News Network

Warmth spurs plants to move or bloom earlier

February 2, 2014 in Adaptation, Phenology, Temperature Increase, United Kingdom, Vegetation changes

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Sign of spring: Bluebells will increasingly need to choose a strategy to let themcope with awarmer planet Image: Nana B Agyei via Wikimedia Commons

Sign of spring: Bluebells will increasingly need to choose a strategy to let them cope with a warmer planet
Image: Nana B Agyei via Wikimedia Commons

By Tim Radford

Plants reacting to climate change have two strategies to deal with increasing warmth: they escape the heat either by moving towards the poles, or by flowering sooner.

LONDON, 2 February – Scientists are one step closer to solving one of the puzzles of the natural world’s response to climate change: why one species migrates and another does not.

Tatsuya Amano of the University of Cambridge in the UK and colleagues report in the Proceedings of the Royal Society B that there could be a relatively simple explanation, especially for plant behaviour. Those that can make new colonies move north (or south, in the southern hemisphere) to take advantage of changing temperature regimes. Others simply shift the time zone: they flower earlier.

The response of flora and fauna to climate change is not a simple one: all sorts of influences are at play, including changes in habitat and in farming methods, in competition from alien introductions, and in the introduction of new kinds of predator.

But over the decades, scientists have been able to measure distinctive shifts. In alpine Switzerland, plants, butterflies and birds were all observed to move uphill  as temperatures shifted through the decades. In Britain, some butterfly populations
were observed to extend their range northwards while others were less able to take advantage of the opportunity to exploit new territory.

Dr Amano and his partners – from Britain, Poland and Germany – looked at a long sequence of historical records to explore the responses of plants. The theory is that over evolutionary time, each species finds a favoured “niche” that suits it best, and occupies it.

As climate conditions change, so should the ideal niche, and plants should shift their ground or respond in some other way. All the research requires is a lot of data, collected over hundreds of years.

General principle

“Britain is the ideal study system for this purpose because historical changes in first flowering dates have been estimated for 405 plant species by applying a hierarchical model to almost 400,000 observation records throughout the country”, say the authors, “and records on spatial distribution are available for 6,669 higher plant taxa throughout Britain at two census periods” (a taxon is a group of natural populations judged by taxonomists to constitute a unit).

They were able to work from 395,466 records of 405 flowering species collected between 1753 and 2009, held by the UK Phenology Network.They also had access to the oldest set of weather records on the planet, the Central England Temperature series, recording daily temperatures since 1772.

By using sophisticated mathematical techniques and a lot of data, the team were able to settle at least one very general principle: if a plant could not take advantage of warmer weather by flowering earlier then there was a greater likelihood that it would shift its range northwards. And there was a complementary relationship: if a plant could not change its ground, it changed its phenology.

The finding gives conservation scientists some more general principles to apply. It also reveals some of the characteristics that might indicate how a species might be predicted to respond. The word “might” is important here. Their findings, the authors say, “need to be carefully interpreted, as our models generally had a low explanatory power.” – Climate News Network

Penguins feel climate change’s impacts

February 1, 2014 in Antarctic, Climate, Extreme weather, Marine ecology, Rainfall, South America, Weather, Wildlife

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Adélie penguin chicks chase an adult in the hope of finding food Image: Liam Quinn from Canada via Wikimedia Commons

Adélie penguin chicks chase an adult in the hope of finding food
Image: Liam Quinn from Canada via Wikimedia Commons

By Tim Radford

Scientists have identified climate change as the direct cause of rising mortality among penguin chicks hatched in Argentina.

LONDON, 1 February – Climate change is bad for penguin chicks. If rain doesn’t soak their feathers and kill them with cold, then extremes of heat could finish them off with hyperthermia.

Over a 27-year research project in the world’s largest colony of Magellanic penguins, on the arid Argentine coast, researchers have seen a greater number of deaths directly attributable to climate change.

“We’re going to see years where almost no chicks survive if climate change makes storms bigger and more frequent during vulnerable times of the breeding season”, says Ginger Rebstock, who, with Dee Boersma, reports on the state of penguin survival in the Public Library of Science journal PLOS One.

The two scientists, biologists from the University of Washington, Seattle in the US, believe starvation and weather are going to make life harder for the offspring of the 200,000 pairs of penguins that breed each year at Punta Tombo, on Argentina’s Atlantic coast.

The number of storms during the first two weeks of December – when all the chicks are less than 25 days old and their downy coats are not yet waterproof – has increased between 1983 and 2010.

Every new chick is at hazard: over the span of study, the researchers calculate that 65% of chicks do not survive, 40% of them die by starvation. But climate change has begun to offer new dangers.

A Magellanic chick, still too young to have an adult's waterproofing, in the rain Image: D Boersma/University of Washington

A Magellanic chick, still too young to have an adult’s waterproofing, in the rain
Image: D Boersma/University of Washington

Some years up to half of all chicks die because of the weather. Punta Tombo is historically an arid region. In the last 50 years, the scientists report, rainfall has increased. The number of wet days has increased, the number of consecutive wet days has increased and the level of rainfall during those days has continued to increase.

Air temperatures changed too. The minimum temperatures decreased by up to 3°C and the number of these colder days increased. Storms, too, make it more difficult for foraging parents to gather enough food to feed their chicks.

Sea ice changes

“Starving chicks are more likely to die in a storm”, says Prof Boersma. “There may not be much we can do to mitigate climate change, but steps could be taken to make sure the Earth’s largest colony of Magellanic penguins have enough to eat by creating a marine protected reserve, with regulations on fishing, where penguins forage while raising small chicks.”

Further south, extreme weather is beginning to make life difficult for the Adélie penguins of Ross Island in Antarctica. Amélie Lescroël from the CNRS in France and colleagues report in the same edition of PLOS One that abnormal sea ice conditions reduce access to food.

Antarctic penguins are of course adapted to sea ice: it is their preferred habitat. But they must respond to short and long term changes in ice levels. For 13 years, scientists have monitored the feeding success of the Ross Island colony and observed that the birds could cope in those seasons when there was less sea ice.

But climate change in Antarctica, too, creates new problems for the birds and limits their foraging efficiency.

“Our work shows that Adélie penguins could cope with less sea ice around their summer breeding grounds”, said Dr Lescroël. “However, we also showed that extreme environmental events, such as the calving of giant icebergs, can dramatically modify the relationship between Adélie penguins and sea ice.”

If the frequency of such extreme events increases, then it will become hard to predict how penguin populations will get by, she thinks. – Climate News Network

Be small, stay cool, forget the climate

January 25, 2014 in Adaptation, Temperature Increase, USA, Wildlife

FOR IMMEDIATE RELEASE

Moose are one of the large species likely to feel more stress in a warming world than smaller creatures Image: Hagerty Ryan, US Fish & Wildlife Service, via Wikimedia Commons

Moose are one of the large species likely to feel more stress in a warming world than smaller creatures
Image: Hagerty Ryan, US Fish & Wildlife Service, via Wikimedia Commons

By Tim Radford

Climate change is not affecting all species equally, US researchers say. The smaller the species, the less stress they are likely to feel than their bigger cousins.

LONDON, 25 January – When it comes to climate change, small could be beautiful. Christy McCain of the University of Colorado Boulder looked at more than 1,000 scientific studies of mammalian behaviour and responses to climate change in North America and came to one big conclusion: bigger animals are more likely to experience stress than the smaller ones. A tiny shrew in the American forests was 27 times less likely to respond to climate change than a moose not far away.

She settled on 140 scientific papers that contained population responses from 73 North American mammal species, and examined a number of observations that could be called a response. Was there some sort of local extinction? Did the creature’s range contract, did it shift, did the species numbers increase? Did seasonal behaviour betray any change? Was there any variation in body size? Or in genetic diversity?

She and her colleague Sarah King report in Global Change Biology that only about half of the mammals responded as expected to climate change; 7% did the opposite of what might be expected and the remaining 41% betrayed no response. Those characteristics that indicated a response to climate change were large body size and restricted times in the day when a mammal might be active.

Tailored conservation

Almost all the large mammals responded negatively to the gradual warming and seasonal shifts of recent decades. Mammals active only in the daylight, or only at night, were twice as likely to respond as mammals that had a more flexible approach to time-keeping.

Mammals in the high latitudes, or at high elevation ranges – polar bears in the first case, American pikas and shadow chipmunks in the second – were also more likely to be in some way affected than those further south or further downhill. Small mammals however seemed to be able to exploit a wider range of micro-climates – shady patches, burrows and so on – to shelter from the effects of climate change.

“Overall the study suggests our large charismatic fauna – animals like foxes, elk, reindeer and bighorn sheep – may be more at risk from climate change”, said Dr McCain. “If we can determine which mammals are responding to climate change and the ones that are at risk of disappearing, then we can tailor conservation efforts toward those individual species.” – Climate News Network