Hi-tech analysis pinpoints Antarctic ice sheet dangers

Hi-tech analysis pinpoints Antarctic ice sheet dangers

Precision mapping of West Antarctica’s melting glaciers could help climate scientists to predict potentially calamitous effects on sea levels.

LONDON, 25 August, 2015 – Scientists have used high-resolution computing techniques to calculate the future of the West Antarctic ice sheet over the next two or three centuries.

The West Antarctic peninsula right now is about the fastest-warming place on Earth. And, in the worst case scenario, glaciers will retreat by hundreds of kilometres, and seas will rise everywhere.

An estimated 80,000 cubic kilometres of ice could flow into the sea by 2100, and by 2200 this could rise to 200,000 cubic kilometres. By the end of this century, sea levels could have risen by 20cms, and 50cms by 2200.

This is an extreme case, but the forecasts for West Antarctica’s glaciers have been consistently alarming. In the last two years, scientists have confirmed that the rates of melt and retreat have accelerated, and that, under the combined effects of warmer air and sea, this melting may be irreversible.

Vulnerable mass

Stephen Cornford, a researcher at the School of Geographical Sciences at the University of Bristol in the UK, and colleagues report in the European Geosciences Union journal The Cryosphere that their chief concern was to help climate science by fixing with greater precision the things that might happen to the most vulnerable mass of ice on the frozen continent.

The new study tests a range of climate predictions in greater detail than before, over a greater area, and a longer period of time. But the uncertainties remain. Will human-induced greenhouse gas levels continue to rise? How will the oceans respond? What will be the consequences for snowfall south of the Antarctic Circle?

“Other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently”

So the study looks at all the possibilities in more detail, and the pay-off could be more confident predictions of climate change as the circumstances begin to change.

Dr Cornford says: “We expect future change in the West Antarctic ice sheet to be dominated by thinning in the Amundsen Sea Embayment, just as it is today, until at least the 22nd century. But other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently.”

A computer-generated map of the projected glacial retreat in the Amundsen Sea Embayment by 2154. Image: S.Cornford et al/The Cryosphere

A computer-generated map of the projected glacial retreat in the Amundsen Sea Embayment by 2154.
Image: S.Cornford et al/The Cryosphere

Serious consequences

The worst-case predictions are disconcerting, and could have serious consequences for the hundreds of millions of people who live in cities and on productive land at or near sea level – for instance on the Nile Delta or in Bangladesh – or even below sea level, protected by sea walls, such as in the Netherlands.

But they remain just that: worst case predictions. The scientists were not concerned with establishing probabilities for any scenario, just with employing complex mathematical techniques to extend climate models.

The chief aim of the study has been to find ways of making sense of all possibilities − from no change to calamitous change − in the factors that govern glacier loss.

Co-author Dan Martin, a computational scientist at the Lawrence Berkeley National Laboratory in California, says: “Much like a higher-resolution digital camera transforms a blur into a flock of birds, higher resolution in a computer model often helps to capture details of the physics involved, which may be crucial to the broad picture.” – Climate News Network

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Global glacier melt reaches record levels

Global glacier melt reaches record levels

Scientists say tens of thousands of glaciers are melting faster than ever − and many will continue to do so even if climate change can be stabilised.

LONDON, 5 August, 2015 – The world’s glaciers are melting fast − probably faster than at any time in recorded history, according to new research.

Measurements show several hundred glaciers are losing between half and one metre of thickness every year − at least twice the average loss for the 20th century − and remote monitoring shows this rate of melting is far more widespread.

The World Glacier Monitoring Service (WGMS), based at the University of Zurich, Switzerland, has compiled worldwide data on glacier changes for more than 120 years.

Drawing on reports from its observers in more than 30 countries, it has published in the Journal of Glaciology a comprehensive analysis of global glacier changes.

Pictorial sources

The study compares observations of the first decade of this century with all available earlier data from field, airborne and satellite observations, and with reconstructions from pictorial and written sources.

Dr Michael Zemp, director of WGMS and lead author of the study, says the current annual loss of 0.5-1 metre of ice thickness observed on “a few hundred glaciers” through direct measurement is two to three times more than the average for the last century.

Evidence of how much the Rhone glacier in the Swiss Alps receded between 2007 (above) and 2014. Images: Simon Oberli

Evidence of how much the Rhone glacier in the Swiss Alps receded between 2007 (above) and 2014. Images: Simon Oberli

CROP-SimonOberli_rhone2014

“However, these results are qualitatively confirmed from field and satellite-based observations for tens of thousands of glaciers around the world,” he adds.

The WGMS compiles the results of worldwide glacier observations in annual calls-for-data. The current database contains more than 5,000 measurements of glacier volume and mass changes since 1850, and more than 42,000 front variations from observations and reconstructions stretching back to the 16th century.

Intense ice loss of the last two decades has resulted in a strong imbalance of glaciers
in many regions of the world

Glaciers provide drinking water for millions of people, as well as irrigating crops and providing hydropower. When they melt, they also make a measurable contribution to sea level rise.

The researchers say the current rate of glacier melt is without precedent at the global scale − at least for the time period observed, and probably also for recorded history, as reconstructions from written and illustrated documents attest.

Long-term retreat

The study also shows that the long-term retreat of glacier tongues is a global phenomenon. Intermittent re-advance periods at regional and decadal scales are normally restricted to a smaller sample of glaciers and have not come close to achieving the Little Ice Age maximum positions reached between the 16th and 19th centuries.

Glacier tongues in Norway, for example, have retreated by some kilometres from their maximum extents in the 19th century. The intermittent re-advances of the 1990s were restricted to glaciers in coastal areas, and to a few hundred metres.

The study shows that the intense ice loss of the last two decades has resulted in what it calls “a strong imbalance of glaciers in many regions of the world”. And Dr Zemp warns: “These glaciers will suffer further ice loss, even if climate remains stable.”

He told Climate News Network: “Due to the strong ice loss over the past few decades, many glaciers are too big under current climatic conditions. They simply have not had enough time to react to the climatic changes of the past.

“So they will have to retreat further until they are in balance with climatic conditions again. In the European Alps, many glaciers would lose about 50% of their present surface area without further climate change.” – Climate News Network

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Half of climate safety level has gone

Half of climate safety level has gone

Global temperatures have risen by 1°C in the past 150 years, and one scientist says doubling that level could unleash catastrophic sea level rise this century.

LONDON, 2 August, 2015 – The world is now halfway towards the internationally-agreed safety limit of a maximum 2°C rise in global average temperatures, researchers say.

That limit seeks to prevent the global warming caused by the burning of fossil fuels exceeding 2°C above the pre-industrial global temperature. The UN’s Paris climate summit later this year aims to ensure that it is not breached.

It appears that the human race has taken roughly 250 years to stoke global warming by 1°C. On present trends, we look likely to add the next 1°C far more quickly – across much of the world, many climate scientists believe, by the middle of this century.

The research is published in the journal New Scientist, which commissioned it. As so often with climate projections, it needs qualifying and teasing apart.

Some scientists, for example, warn that there’s uncertainty about just what the pre-industrial global temperature was. The New Scientist research is careful to be specific: it says global surface temperature is now passing 1°C of warming relative to the second half of the 19th century.

Farewell, hiatus

And one of the four main trackers of temperature thinks that milestone will be passed only if there is a strong El Niño, the cyclic Pacific weather phenomenon that periodically brings widespread chaos in its wake.

However, the research looks likely finally to lay to rest the argument that global warming is slowing and stuttering to a virtual halt, the so-called hiatus theory. Kevin Trenberth, of the US National Center for Atmospheric Research in Boulder, Colorado, told New Scientist: There’s a good chance the hiatus is over.”

The hottest year since records began was by a very small margin – 2014, and this year’s El Niño could mean a temperature rise of 0.1°C this year, an increase which usually takes about a decade to develop. Dr Trenberth thinks 2015 is likely also to be a record-breaker. 

Between 1984 and 1998 the Earth warmed at 0.26°C a decade, but the Intergovernmental Panel on Climate Change (IPCC)  says the rate then fell back until 2012 to about 0.04°C, for a number of reasons, including a less active Sun, more cooling aerosols from volcanoes and Asian factories, and more heat being absorbed by the oceans. The New Scientist findings suggest that warming may soon revert to the higher rate. 

From a quite different source comes a warning not only that temperatures may soon start a marked rise, but that sea level may also accelerate far faster than most scientists think likely.

It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable”

The prospect it holds out is at odds with most mainstream climate science, and might well be discounted as alarmist and fanciful. But the lead author of the discussion paper in which it appears is the highly respected James Hansen, former director of NASA’s Goddard Institute for Space Studies.

He and his colleagues say the ice melting around Greenland and Antarctica will cause sea level rises much faster than mainstream predictions suggest, by several metres this century. This will add to a process which they say has already begun, accelerating the melting of the undersides of Antarctic glaciers and ice shelves.

Another consequence, they think, will be the shutting down of ocean currents which carry heat from the tropics to the polar regions, leaving the tropics to warm fast and the high latitudes to cool. This temperature difference, they say, will spawn superstorms unlike any seen so far.

All this, Professor Hansen and his colleagues say, could happen with a 2°C temperature rise, with devastating consequences: It is not difficult to imagine that conflicts arising from forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilisation.”

Professor Hansen may of course be wrong, but it would be short-sighted to assume that he is. He has a strong record of ultimately being proved right. Climate News Network

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Mangroves hold key to Indonesia’s emissions cuts

Mangroves hold key to Indonesia’s emissions cuts

New study says Indonesia could go a quarter of the way to reaching its 2020 target for carbon emissions reduction by ending the destruction of its vital mangrove forests.

LONDON, 27 July, 2015 – Indonesia, one of the world’s largest carbon emitters, would take a major step towards losing that tag by protecting its massive mangrove forests, according to new research.

The mangroves, which store prodigious quantities of carbon, are currently disappearing fast − often destroyed to make room for aquaculture to satisfy the wants of lucrative foreign markets.

But a team from the Centre for International Forestry Research (CIFOR) and colleagues report in the journal Nature Climate Change that protecting the mangroves could take Indonesia a quarter of the way to achieving the whole of the greenhouse gas emissions cuts it plans for 2020.

Indonesia, with the longest coastline in the tropics, has more mangroves than any other country − more than 2.9 million hectares. But it also has one of the world’s fastest rates of mangrove loss.

The main threats to the forests include conversion to shrimp ponds, logging, conversion of land to agriculture or salt pans, and degradation by oil spills and pollution.

In 2013, Indonesia’s revenue from shrimp exports was close to US$1.5bn, almost 40% of the total revenue from the country’s fishery sector.

Grave threat

The researchers say the Indonesian mangroves, some of which grow to 50 metres in height, store 3.14 billion tonnes of carbon, which amounts to one-third of the carbon stored in Earth’s coastal ecosystems.

But they are under grave threat. In the last 30 years, 40% of these coastal forests have gone, and the annual rate of loss now is about 52,000 hectares, causing substantial greenhouse gas emissions.

The current rate of destruction means that 190 million tonnes of CO2-equivalent (CO2e) are emitted annually. That is 42% of the world’s annual emissions from the destruction of coastal ecosystem services − marshes, mangroves and sea grasses.

Put more graphically, Indonesia’s destruction of its mangroves emits as much greenhouse gas as if every car in the country was driven around the world twice.

“We hope that these numbers help policymakers see mangroves as a huge opportunity for climate change mitigation,” says Daniel Murdiyarso, principal scientist at CIFOR and lead author of the paper.

“It is time to acknowledge that mangroves must be part of the solution to climate change”

“But to make progress, it is crucial that mangroves are protected and managed sustainably. It is time to acknowledge that mangroves must be part of the solution to climate change.”

Dr Murdiyarso is also co-author of a CIFOR guide on climate change adaptation and mitigation in Indonesia’s wetlands.

In a separate study, published in the Royal Society Proceedings A, further light is shed on the crucial role mangroves play in protecting coastal areas from sea level rise caused by climate change.

The study, by researchers at the University of Southampton, UK, and colleagues from the universities of Auckland and Waikato in New Zealand, used mathematical simulations to discover how mangrove forests respond to elevated sea levels.

Mesh-like roots

When sea levels rise, they found, areas in estuaries and river deltas without mangroves are likely to widen from erosion, and more water will encroach inwards. But mangrove regions prevent this effect, probably because of soil building up around the trees’ mesh-like roots and acting to reduce energy from waves and tidal currents.

Dr Barend van Maanen, a coastal systems researcher in the department of engineering and environment at the University of Southampton, explains: “As a mangrove forest begins to develop, the creation of a network of channels is relatively fast. Tidal currents, sediment transport and mangroves significantly modify the estuarine environment, creating a dense channel network.

“Within the mangrove forest, these channels become shallower through organic matter from the trees . . . and sediment trapping (caused by the mangroves), and the sea bed begins to rise, with bed elevation increasing a few millimetres per year until the area is no longer inundated by the tide.”

In modelling of sea level rise in the study, the ability of mangrove forest to gradually create a buffer between sea and land occurs even when the area is subjected to potential sea level rises of up to 0.5mm per year.

“These findings show that mangrove forests play a central role in estuarine and salt marsh environments,” says Giovanni Coco, associate professor in the school of environment at the University of Auckland.

“As we anticipate changes caused by climate change, it’s important to know the effect sea level rise might have, particularly around our coasts.” − Climate News Network

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Global warming’s record-breaking trend continues

Global warming’s record-breaking trend continues

Detailed update by hundreds of scientists on climate indicators in 2014 reveals highest recorded rises in temperatures, sea levels and greenhouse gases.

LONDON, 22 July, 2015 – Forget talk of a slowdown in global warming. Scientists say the climate is heading smartly in the opposite direction, with 2014 proving to be a record-breaking year.

The US National Oceanic and Atmospheric Administration (NOAA), one of the most respected sources of climate science, says that last year “the most essential indicators of Earth’s changing climate continued to reflect trends of a warming planet”. Some − including rising land and ocean temperatures, sea levels and greenhouse gases − reached record highs.

The authoritative report by the NOAA’s Centre for Weather and Climate at the National Centres for Environmental Information (NCEI), published by the American Meterological Society, draws on contributions from 413 scientists in 58 countries to provide a detailed update on global climate indicators.

“The variety of indicators shows us how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere,” says Thomas R. Karl, director of the NCEI.

Rising concentrations

The authors report that concentrations of greenhouse gases continued to climb during the year. Atmospheric carbon dioxide concentrations rose by 1.9 parts per million (ppm), reaching a global average of 397.2 ppm for the year. This compares with a global average of 354ppm in 1990 when the first edition of this report was published. And levels of methane and nitrous oxide also went up.

“Variety of indicators shows how our climate is changing, not just in temperature but from the depths of the oceans to the outer atmosphere”

Four independent global datasets showed that 2014 was the warmest year on record, with the warmth widespread across land areas.

Europe experienced its warmest year; Africa had above-average temperatures across most of the continent throughout 2014; Australia recorded its third warmest year; and Mexico had its warmest. Eastern North America was the only major region to experience below-average annual temperatures.

Global average sea level rose to a record high, and the globally averaged sea surface temperature was also the highest recorded. The warmth was particularly notable in the North Pacific Ocean, where temperatures are in part probably driven by a transition of the Pacific decadal oscillation – a recurring pattern of ocean-atmosphere climate variability centred in the region.

Earlier snow melt

The Arctic continued to warm, and sea ice extent remained low. Arctic snow melt occurred 20–30 days earlier than the 1998–2010 average. On the North Slope of Alaska, record high temperatures at a 20-metre depth were measured at four of five permafrost observatories. The eight lowest minimum sea ice extents during this period have occurred in the last eight years.

But temperature patterns across the Antarctic showed strong seasonal and regional patterns of warmer-than-normal and cooler-than-normal conditions, resulting in near-average conditions for the year for the continent as a whole. Last year was the third consecutive year of record maximum sea ice extent in the Antarctic.

The El Niño-Southern Oscillation (ENSO), a periodic warming of the water in the central and eastern Pacific that disrupts weather over thousands of miles, was in a neutral state during 2014, although it was on the cool side of neutral at the beginning of the year and approached warm El Niño conditions by the end of the year. This pattern played a major role in several regional climate outcomes.

There were 91 tropical cyclones in 2014, well above the 1981-2010 average of 82 storms. But the North Atlantic season, as in 2013, was quieter than most years of the last two decades with respect to the number of storms. – Climate News Network

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Climate threat as grave a risk as nuclear war

Climate threat as grave a risk as nuclear war

An international scientific report commissioned by the UK government says the risks of climate change are comparable to those posed by nuclear conflict.

LONDON, 18 July, 2015 – The UK government says that climate change poses risks that demand to be treated as seriously as the threat  of nuclear war.

Scientists from the UK, US, India and China say in a report commissioned by the UK that deciding what to do about climate change depends on the value we put on human life, both now and in years to come.

One of the lead authors of the report is Sir David King, formerly the UK government’s chief scientist, who last month co-authored a report on the scale of investment that should be made to move from fossil fuels to renewable energy by 2025. 

In a foreword to the latest report, Baroness Anelay, a minister at the British foreign office, writes that assessing the risks surrounding nuclear disarmament and non-proliferation means understanding inter-dependent elements − including what science says is possible, what other countries may intend, and systemic factors such as regional power dynamics.

“The risk of climate change demands a similarly holistic assessment,” she says.

Value human life

She concludes: “How much do we care about the effects of climate change? How important is it that we act to avoid them? What probability of their occurrence can we tolerate?…The answers to these questions depend in part on how we value human life – both now, and in the future.”

The report is not the first to put climate chaos and nuclear devastation in the same category of risk, but its sponsorship by one of the world’s nuclear powers is eloquent.

It says the most important political decision is how much effort to exert on countering climate change, taking into account what we are doing to the climate, how it may respond, what that could do to us, and what we might then do to each other.

The authors’ best guess, based on current policies and trends, is that greenhouse gas emissions will keep going up for another few decades, and then either level off or slowly decline.

“Uncertainty is not our friend. There is much more scope to be unlucky than there is to be lucky”

This, they say, is for two reasons: governments are not making maximum use of the technologies already available; and technology is not yet progressing fast enough to give governments the policy options they will need. In the worst case, emissions could keep on rising throughout the century.

They warn that how the climate may change, and what that could do to us, are both highly uncertain. “The important thing to understand is that uncertainty is not our friend,” the report says. “There is much more scope to be unlucky than there is to be lucky.”

High emissions pathway

The report foresees wide ranges of possible global temperature and sea level increase. On a high emissions pathway, it says, where the most likely temperature rise is estimated at 5°C by 2100, anything from 3°C to 7°C may be possible.

On this pathway, the chances of staying below 3°C will become “vanishingly small”, but the chances of exceeding 7°C will increase and could become more likely than not within the next century.

The authors see very little chance that global sea level rise will slow down, and every chance that it will accelerate. The only question is by how much.

“While an increase of somewhere between 40cm and 1m looks likely this century, the delayed response of huge ice-sheets to warming means we may already be committed to more than 10m over the longer term. We just do not know whether that will take centuries or millennia.”

A temperature increase of 4°C or more could pose very large risks to global food security, and to people.

Humans have limited tolerance for combinations of high temperature and humidity. Their upper limits of tolerance are rarely if ever exceeded by climatic conditions alone, but with temperature increase somewhere between 5°C and 7°C, it starts to become likely that hot places will experience conditions that are fatal even for people lying down in the shade.

Population growth alone is also likely to double the number of people living below a threshold of extreme water shortage by mid-century.

Sea level thresholds

Coastal cities, according to the report, probably have thresholds in terms of the rate and extent of sea level rise that they can deal with, but we have very little idea where those thresholds are.

The authors say that even the 0.8°C of climate change experienced so far is now causing us significant problems, and that “it seems likely that high degrees of climate change would pose enormous risks to national and international security” − for example, through extreme water stress and competition for productive land.

In a highly topical passage, they say migration from some regions may become more a necessity than a choice, and could happen on a historically unprecedented scale.

“The capacity of the international community for humanitarian assistance, already at full stretch, could easily be overwhelmed,” the report warns.

The risks of state failure could rise significantly, affecting many countries simultaneously, and even threatening those currently considered developed and stable.

But the report is not relentlessly downbeat. “An honest assessment of risk is no reason for fatalism,” it says. “Just as small changes in climate can have very large effects, the same can be true for changes in government policy, technological capability, and financial regulation… the goal of preserving a safe climate for the future need not be beyond our reach.” – Climate News Network

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Alaska’s glaciers melt faster as climate change speeds up

Alaska's glaciers melt faster as climate change speeds up

Climate change rather than natural causes is the main cause of Alaska’s glacier loss, which is set to speed up, US scientists say.

LONDON, 30 June, 2015 – The glaciers of Alaska are melting and retreating: the chief cause is climate change and the loss of ice is unlikely to slow, according to a new study by US scientists.

They calculate that the frozen rivers of the Pacific coast of America’s northernmost state are melting fast enough to cover the whole of Alaska with 30 cms of water every seven years.

Since Alaska is enormous – it covers 1.5 million square kilometres and is the size of California, Texas and Montana put together – this adds up to a significant contribution to sea level rise.

“The Alaska region has long been considered a primary player in the global sea level budget, but the exact details of the drivers and mechanisms of Alaska glacier change have been stubbornly elusive,” said Chris Larsen, a geophysicist at the University of Alaska Fairbanks, and lead author of a study in Geophysical Research Letters.

Taxonomy of change

Scientists from the University of Alaska and the US Geological Survey analysed studies of 116 glaciers in the Alaska region over a 19-year-period to estimate the rate at which ice melted and icebergs calved.

They used airborne lidar remote sensing technology and other techniques, historical data and a global glacier inventory to establish a kind of taxonomy of glacier change.

The Columbia Glacier in Prince William Sound had retreated more than 19 kilometres because of iceberg calving and had thinned by 450 meters in height since 1980. But, unexpectedly, tidewater glaciers – those that end in the ocean – seemed to make comparatively little contribution to sea level rise.

“Instead we show that glaciers ending on land are losing mass exceptionally fast, overshadowing mass changes due to iceberg calving, and making climate-related melting the primary control on mountain glacier mass loss,” Dr Larsen said.

Big contributor

He and his colleagues calculated that Alaska is losing ice at the rate of 75 billion metric tons a year. Such research is just one more piece of careful cross-checking in the great mosaic of climate research: another systematic confirmation that overall, glaciers are not losing ice in response to some natural cycle of change of the kind that occasionally confuses the picture for climate science.

The agency at work is largely global warming as a response to the steady rise in atmospheric carbon dioxide as a consequence of the burning of fossil fuels.

Mountain glaciers represent only 1% of the total ice on the planet: the other 99% is found in Greenland – which is melting fast – and in the great frozen continent of Antarctica, where ice mass is being lost at an increasing rate.

But although the mountains of the temperate and tropic zones bear only a tiny percentage of the planet’s ice, their melting accounts for almost a third of the sea level rise currently measured by oceanographers, and this melting will go on to become a big contributor to the sea levels later this century.

“Alaska will continue to be a major driver of sea level change in the upcoming decades”

Across the border in Canada, glaciologists have warned that the country will lose a huge volume of flowing ice, and while one team has confirmed that air pollution rather than global warming long ago began to strip Europe’s Alps of their glaciers, in general mountain peaks are warming faster than the valleys and plains below them.

Geophysicists and glaciologists have established that the glaciers of the tropical Andes are at risk, and in the Himalayan mountain chain glaciers seem to be in inexorable retreat with consequences that could be devastating for the many millions in the Indian subcontinent and in China who rely on seasonal meltwater for agriculture.

Glaciers are by definition hard to study – they are high, cold and in dangerous terrain – and such research is inevitably incomplete: the scientists for instance excluded glaciers smaller than three square kilometres. But together these small patches of flowing ice account for 16% of Alaska’s glaciated landscape. The 116 glaciers in the survey together added up to only 41% of the state’s glaciated area.

But the pattern established by the Fairbanks team suggests that melting will accelerate with climate change. “Rates of loss from Alaska are unlikely to decline, since surface melt is the predominant driver, and summer temperatures are expected to increase,” said Dr Larsen.

“There is a lot of momentum in the system, and Alaska will continue to be a major driver of sea level change in the upcoming decades.” – Climate News Network

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Scientists detect mysterious warming in US coastal waters

Scientists detect mysterious warming in US coastal waters

Unprecedented ocean temperature rises off the Atlantic and Pacific coasts of the US may be linked to sea level rise or the recent pattern of “weird” weather.

LONDON, 28 June, 2015 − Oceanographers are puzzled by an accelerated burst of warming sea that threatens the fisheries of the American Atlantic coast.

Meanwhile, off the US West coast, scientists report that they have been baffled by a mysterious “blob” of water up to 4°C warmer than the surrounding Pacific, linked to weird weather across the entire country.

Jacob Forsyth and research colleagues from the Woods Hole Oceanographic Institution (WHOI) in Massachusetts report in the Journal of Geophysical Research: Oceans that the ocean off the US north-east continental shelf has been warming at unprecedented levels for 13 years.

Their findings came after analysis of data from sensors − called bathythermographs − dropped 14 times a year from the container ship Oleander, which for 37 years has travelled between New Jersey and Bermuda. Each detector takes the temperature of the water column as it sinks up to 700 metres.

Startling discovery

What they were startled to discover was an unexplained, and unprecedented, rise in the water temperatures that may be linked with an equally mysterious sea level anomaly: sea levels are going up, but they are going up faster off the north-east coast of the US than almost anywhere else.

“The warming rate since 2002 is 15 times faster than from the previous 100 years,” says Glen Gawarkiewicz, a WHOI senior scientist and one of the authors of the report.

“There’s just been this incredible acceleration to the warming, and we don’t know if it’s decadal variability or if this trend will continue.”

“It’s producing conditions that we think are going to be more common with global warming”

To make sure of their perspective, the authors compared their analysis with surface data from the Nantucket lightship and other such installations along the coast, from 1880 to 2004. The new study shows that the warming is not just confined to surface waters.

Although there must be some link with the steady rise in atmospheric temperatures because of global warming as a result of human-made carbon dioxide emissions, the oceanographers suspect there may also be another explanation, so far undiscovered.

Off the Pacific coast, meteorologists have been scratching their heads over the appearance in 2014 of a “remarkably” warm patch −  1,500 kilometres across in every direction and 100 metres deep − that could be linked to “weird” weather across the continental US that has seen heat and drought in the west and blizzards and chills in the East.

High pressure ridge

Nicholas Bond,  a research meteorologist at the University of Washington in Seattle, and colleagues report in Geophysical Research Letters that what they have called “the blob” was linked to a persistent high pressure ridge, linked in turn to a calmer ocean during the last two northern hemisphere winters.

The blob plays a sure role in the West Coast weather. Air sweeping across it picks up heat, and this results in warmer temperatures and lower snowpack in coastal mountains − which certainly stoke up the conditions for drought.

A second study in Geophysical Research Letters links the warm Pacific puzzle to the big freeze in the eastern states in 2013 and 2014.

Once again, there doesn’t seem to be a direct connection with climate change, but it raises the spectre of changes to come.

“This is a taste of what the ocean will be like in future decades,” Dr Bond says. “It wasn’t caused by global warming, but it’s producing conditions that we think are going to be more common with global warming.” − Climate News Network

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New flood alert as warming raises sea levels threat

New flood alert as warming raises sea levels threat

Scientists warn countries in northern Europe to plan for dramatic new worst-case scenarios as climate change increases the risk of seas sweeping inland.

LONDON, 22 June, 2015 − Europe could face a higher marine invasion than anybody anticipated. As polar ice melts, tides could be as much as 1.5 metres higher around the coasts of Scandinavia, Germany, the Netherlands and England, according to a new study.

This is considerably higher than the average sea level rise – driven by global warming as a consequence of burning fossil fuels – projected by the Intergovernmental Panel on Climate Change under a “business as usual” scenario and a global average temperature rise of 4°C.

But there is no contradiction. The discrepancy arises because the seas have never been level, and the land keeps moving too.

Aslak Grinsted, associate professor in the Centre for Ice and Climate at the Niels Bohr Institute of the University of Copenhagen, Denmark, and colleagues report in the journal Climate Research that they took a closer look at the dynamics of sea level change in the North Sea, the North Atlantic and the Baltic for the remainder of this century.

Land uplift

“Even though the oceans are rising, they do not rise evenly across the globe,” Dr Grinsted says. “This is partly due to changes in the gravitational field and land uplift.”

He and his colleagues started with the anomalies they knew best. These are in Greenland, which is covered by a sheet of ice so massive that it gathers up the sea around it. So, to reach Greenland, ships must sail uphill.

As the ice sheet melts – and there are studies that show it is melting at an accelerating rate that would heighten sea levels by 14 cms this century – the mass will be reduced and the sea levels will fall, even though more water has entered the oceans.

“In England . . . we cannot exclude a sea level rise of up to 1.75 metres this century”

But although waters are notionally lapping ever higher along coastlines, these too are changing. Northern Europe 12,000 years ago was covered by deep ice, and the bedrock below was depressed. Now the ice has gone, but the land once crushed by it is still rising.

Equipped with the latest research and measurements, the Copenhagen team began their reinterpretation of the local future. They found that what had once been considered “high” scenarios for the Netherlands and England will be surpassed.

Best estimate

Dr Grinsted says: “For London, the calculated best estimate is that sea level will rise by 0.8 metres. In England, a sea level rise of more than 0.9 meters in this century has been considered highly unlikely, but our new calculation shows that there is a 27% chance that this limit is surpassed, and we cannot exclude a sea level rise of up to 1.75 metres this century.”

For the Netherlands, the best estimate of sea level rise is 0.83 metres, but the calculations show that there is a 26% chance that it will exceed the existing high-end scenario of 1.05 metres, and could even reach 1.80 metres.

Dr Grinsted says: “Both countries have already established protections for the coasts with barriers, sluice gates and dikes, but is it enough? I hope that our calculations for worst-case scenarios will be taken into consideration as the countries prepare for climate change.”

The IPCC sea level projection is of 80 cms worldwide. Sea levels overall might change little in Scotland, Ireland and Norway. And in the Gulf of Bothnia, in Finland, where the land is rising even faster than the sea, tides could be as much as 10cms lower at the end of the century. − Climate News Network

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Delegates accused of ‘fiddling’ while the planet burns

Delegates accused of ‘fiddling’ while the planet burns

Tame end to Bonn climate talks leaves critics fearing that hopes are fading of a binding agreement being signed to keep global warming in check.

LONDON, June 11, 2015 − For a meeting on which the future of the planet depends, there were remarkably few headlines coming out of the UN climate change conference in Bonn as it ended yesterday.

Critics believe that progress, after nearly two weeks of talks, was so slow that the chances of world leaders signing up to an agreement on tackling climate change in Paris later this year are receding − and that there is a lack of political will to do so.

Delegates agreed that a “streamlined” text of a legal agreement based on the negotiations so far should be drawn up and sent to governments to review.

This will cover issues such as how the agreement can be financed, who will cut greenhouse gas emissions, how to adapt to climate change, and compensation for nations badly affected. The negotiators will then come back to Bonn and try again.

Optimists will argue that this is progress, and that the talks were not supposed to be final, but merely moving towards a legally-binding agreement that will be signed by heads of state at the UN Framework Convention on Climate Change in Paris in December.

Sleepwalking

However, for many environment groups lobbying the talks, it was certainly not enough. The phrase “sleepwalking into Paris” was how Christian Aid  described it.

Their senior climate change adviser, Mohamed Adow, was quoted by the BBC as saying: “There has been too much time spent fiddling around with the unimportant details of the text. Negotiators have acted like schoolchildren colouring in their homework timetable and not getting round to any actual homework.”

It was not all bad news. One of the surprising breakthroughs was an agreement that will enable poorer countries to receive money for keeping their forests standing.

Trying to preserve the world’s forests in order to store carbon, and so protect the climate, has been a thorny issue since the first Earth Summit in Rio in 1992.

“Negotiators have acted like schoolchildren colouring in their homework timetable and not getting round to any actual homework”

The scheme for Reducing Emissions from Deforestation and Forest Degradation, known as UN-REDD, was originally going to be a Forest Convention, but developing countries rejected that on the grounds that it was up to them how they used their own natural resources. In any case, they said, the developed world had already cut down its forests.

After 20 years of talking, the increasing recognition that forests are more valuable in their pristine state than logged or clear-cut, and that rich countries were prepared to compensate poorer ones for not cutting them down, finally led to agreement.

Brazil, still battling to reduce Amazon deforestation, was among the countries pushing for an early settlement.

Package of deals

Although the agreement has been reached, it cannot come into operation until the end of the Paris conference, when it is supposed to be part of the package of deals that will save the climate from going over the internationally-agreed 2˚C temperature rise limit above pre-industrial levels.

The main sticking point in the past, at the Bonn talks, and for the future is the small matter of $100 billion pledged in aid by the rich countries to developing nations by 2020 to help them to adapt to climate change and still develop at the same time.

Money has been trickling in to various funds set up for the purpose, but there is no sign that the bulk of the donations will actually materialise.

Another serious problem is that the pledges that larger countries have made to reduce emissions are not enough to stop the world overheating beyond the 2˚C limit agreed by politicians.

So far, more than 30 countries have pledged to limit emissions of greenhouse gases, with around 150 smaller countries yet to set goals.

A bright spot on the pledges front was the agreement of the G7 group of countries to phase out all electricity production from fossil fuels by the end of this century.

However, as critics pointed out, what the leaders failed to do was outline any measures they were prepared to take now to set the world on the right course.

Another vexed issue yet to be resolved is compensation for the loss and damage suffered by poorer countries because of sea level rise and storms for which they are not responsible.

Impatient with progress at the talks, some of the poorer nations − Vanuatu, Kiribati, Tuvalu, Fiji, the Solomon Islands, and the Philippines − announced that they would be taking a human rights case again big oil, coal and gas companies, and demanding compensation.

There are signs that public opinion − so often in the past indifferent to the issue of climate change − is now taking the issue more seriously.

A vast poll that involved testing public opinion in 70 countries on the same day found that 80% of people are very concerned about climate change, and 67% back a legally-binding agreement for all countries to reduce emissions.

Avoided showdown

Jan Kowalzig, Oxfam climate change policy adviser, summed up the feelings of environmental observers in Bonn when he said: “Negotiators avoided a showdown over crunch issues such as finance and increasing near-term emissions cuts, but they are only delaying the inevitable.

“A clearer mandate from heads of state and ministers is needed to ignite the talks and ensure key questions are answered.

“Political leaders need to give a clear steer on how to address the inadequacy of current emissions reductions pledges, but also on the urgent financial support needed for the most vulnerable countries and populations.”

Once governments have had a chance to review the “streamlined texts”, delegates will return to Bonn in August and October for more rounds of talks, before the Paris summit at the end of the year. – Climate News Network

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