Tag Archives: Sea levels

Fresh water causes Antarctic seas to rise faster

Meltwater from Antarctic glaciers is causing sea levels to rise Image Jason Auch via Wikimedia Commons
Glacial meltwater is a key factor in the sea level rise in Antarctica
Image Jason Auch via Wikimedia Commons

By Tim Radford

Researchers in the UK have established that billions of tonnes of fresh water from melting glaciers are causing Antarctic sea levels to rise much higher and faster than the global average.

LONDON, 7 September, 2014 − Sea levels around Antarctica are rising faster than anywhere else in the southern ocean. The global average rise in ocean heights in the last 19 years has been 6cms, but the rise in seas around Antarctica is 2cms higher.

This seemingly counter-intuitive finding is certainly a consequence of melting ice in the Southern Ocean, but the connection with global warming is, for the moment, tenuous. The agency that is behind the rising sea levels is simply an excess of fresh water from melting glaciers − about 350 billion tonnes of it.

“Fresh water is less dense than salt water, and so in regions where an excess of fresh water has accumulated we expect a localised rise in sea level,” says Craig Rye, an oceanography researcher at of the University of Southampton in the UK, who, with colleagues, has published the findings in Nature Geoscience.

Partly because the oceans are warmer and are therefore expanding, and partly because the terrestrial glaciers are in retreat, global sea levels on average have crept up by about 3 millimetres a year. Waters off the Antarctic shelf seem to be gaining an additional 2mm a year.

Less saline

The scientists studied satellite scans of a region of more than a million square kilometres to make their finding, and used ship-based studies of the Antarctic sea water to confirm that is has become less saline.

The melting of the Antarctic ice sheet – German scientists recently calculated that around 125 cubic kilometres of meltwater is running off the continent each year − and the thinning of the floating ice shelves is enough to explain the unexpected rise.

Computer model studies confirm the interpretation that the rise is happening because the southern seas have just got fresher. The consequences in the longer term are uncertain.

Rye, a postgraduate researcher, said: “The interaction between air, sea and ice in these seas is central to the stability of the Antarctic ice sheet and global sea levels, as well as other environmental processes, such as the generation of Antarctic bottom water, which cools and ventilates much of the global ocean abyss.” – Climate News Network

Doors open at Ban Ki-moon’s ‘Last Chance Saloon’

Waves wash against the runway at Nauru airport, where sea level rise is a daily reality Image: Dept of Foreign Affairs and Trade via Wikimedia Commons
The runway at Nauru island’s airport in the South Pacific, where sea level rise is a daily reality
Image: Matt Robertson/Australian DFAT via Wikimedia Commons

By Paul Brown

The UN secretary-general is attempting to prevent world leaders sleepwalking into disaster by asking them to make new pledges at a climate summit this month on cutting greenhouse gases.

LONDON, 3 September, 2014  It is widely acknowledged that the planet’s political leaders and its people are currently failing to take enough action to prevent catastrophic climate change.

Next year, at the United Nations climate change conference in Paris, representatives of all the world’s countries will be hoping to reach a new deal to cut greenhouse gases and prevent the planet overheating dangerously. So far, there are no signs that their leaders have the political will to do so.

To try to speed up the process, the UN secretary-general, Ban Ki-moon, has invited world leaders to UN headquarters in New York on 23 September for a grandly-named Climate Summit 2014.

He said at the last climate conference, in Warsaw last year, that he is deeply concerned about the lack of progress in signing up to new legally-binding targets to cut emissions.

If the summit is a success, then it means a new international deal to replace the Kyoto Protocol will be probable in late 2015 in Paris. But if world leaders will not accept new targets for cutting emissions, and timetables to achieve them, then many believe that political progress is impossible.

Danger threshold

Ban Ki-moon’s frustration about lack of progress is because politicians know the danger we are in, yet do nothing. World leaders have already agreed that there is no longer any serious scientific argument about the fact that the Earth is heating up and  if no action is taken  will exceed the 2°C danger threshold.

It is also clear, Ban Ki-moon says, that the technologies already exist for the world to turn its back on fossil fuels and cut emissions of greenhouse gases to a safe level.

What the major countries cannot agree on is how the burden of taking action should be shared among the world’s 196 nations.

Ban Ki-moon already has the backing of more than half the countries in the world for his plan. These are the most vulnerable to climate change, and most are already being seriously affected.

More than 100 countries are currently meeting in Apia, Samoa, at the third UN Conference on Small Island Developing States, which ends tomorrow. In their draft final statement, they note with “grave concern” that world leaders’ pledges on the mitigation of greenhouse gases will not save them from catastrophic sea level rise, droughts, and forced migration.

“We express profound alarm that emissions
of greenhouse gases continue to rise globally”

Many of them have long advocated a maximum temperature rise of 1.5°C to prevent disaster for the most vulnerable nations, such as the Marshall Islands and the Maldives.

The draft ministerial statement says: “Climate change is one of the greatest challenges of our time, and we express profound alarm that emissions of greenhouse gases continue to rise globally.

“We are deeply concerned that all countries, particularly developing countries, are vulnerable to the adverse impacts of climate change and are already experiencing an increase in such impacts, including persistent drought and extreme weather events, sea level rise, coastal erosion and ocean acidification, further threatening food security and efforts to eradicate poverty and achieve sustainable development.”

Devastating consequences

Speaking from Apia, Shirley Laban, the convenor of the Pacific Islands Climate Action Network, an NGO, said: “Unless we cut emissions now, and limit global warming to less than 1.5°C, Pacific communities will reap devastating consequences for generations to come. Because of pollution we are not responsible for, we are facing catastrophic threats to our way of life.”

She called on all leaders attending the UN Climate Summit in New York to “use this historic opportunity to inject momentum into the global climate negotiations, and work to secure an ambitious global agreement in 2015”.

This is a tall order for a one-day summit, but Ban Ki-moon is expecting a whole series of announcements by major nations of new targets to cut greenhouse gases, and timetables to reach them.

There are encouraging signs in that the two largest emitters – China and the US – have been in talks, and both agree that action is a must. Even the previously reluctant Republicans in America now accept that climate change is a danger.

It is not yet known how many heads of state will attend the summit in person, or how many will be prepared to make real pledges.

At the end of the summit, the secretary-general has said, he will sum up the proceedings. It will be a moment when many small island states and millions of people around the world will be hoping for better news.  Climate News Network

Plan to make renewables cheaper than coal within 10 years

 

Solar power in India: Could renewables answer the world's energy needs? Image: Bkwcreator via Wikimedia Commons

Solar power in India: Could renewables answer the world’s energy needs?
Image: Bkwcreator via Wikimedia Commons

By Alex Kirby

Three weeks before the UN Secretary-General’s extraordinary meeting of world leaders in New York to tackle climate change, a leading British scientist unveils plans for a global low-carbon fund on a par with the Apollo Moon programme.

LONDON, 2 September 2014 – There are prospects of significant progress in the response of world governments to climate change, according to a former UK Government chief scientist, Sir David King.

“There are signs that a leadership role is beginning to emerge”, he told a conference in London held by the Green Economy Coalition.

Sir David also announced that he and a colleague are working with governments to raise funds to help all countries, including developing countries,  to switch to renewable energy. Their scheme hopes to raise nearly as much as the cost of the Apollo programme, NASA’s moon-landing project.

“President Obama is getting ready to commit the US to action, and last week the Chinese Prime Minister, Li Kichiang, announced that his country’s emissions had fallen by 5% in a year”, he said.

“The US and China are positioning themselves for an agreement. And that’s not all. The first speech by the new leader of India, Narendra Modi, spoke of his determination ‘to solarise’ the economy.

Ice in retreat

“Brazil’s emissions, including from deforestation, have fallen from 16.5 tonnes per person to 6.5 tonnes since 2005. Across the Andes in Peru, where the UN climate convention negotiations will take place in December, they know well enough about climate change.

“From Lima they can see the ice retreating up the mountains. At its lowest point it is now 1,000 metres above where it reached to 30 years ago..”

Sir David praised the UK’s commitment to cut greenhouse emissions by 80% by 2050, compared with their 1990 levels. He said the target – matched by Mexico – was likely to be met. The biggest climate challenge confronting the UK, he said, was from rising sea levels.

Some critics say, despite this, that the UK Government is dragging its feet, especially on supporting renewable energy. With a colleague, the economist Professor Lord Richard Layard, Sir David is working on a scheme to raise money to address this.

“It’s called the Global Apollo Programme”, he explained. “We are urging all governments to form a Commission to spend 0.02% of their GDP, which should raise US$10-20 bn p a over 10 years,  to fund RD&D for low-carbon technology.

“We are encouraging governments to launch the Programme at the UN during Ban Ki-moon’s Climate Summit on 23 September. The objective is that by 2020 renewable power should be cheaper than coal in all sunny parts of the world, and by 2025 in all parts of the world.”

Sir David, who for seven years was the UK Government’s chief scientist, is now its Foreign Secretary’s special representative for climate change. Asked if he were hopeful about progress to tackle climate change, he replied: “I’m in this job because I’m an optimist.”

Global reach

His hopes were echoed by another speaker, Hunter Lovins, president of the Colorado-based Natural Capitalism Solutions.  She told the Climate News Network: “We can do it. But it’s going to be tough. So will we do it?

“I don’t agree with the exponents of the idea of near-term human extinction (NTHE), who say we face total collapse by around 2030 or 2035.

‘”What we need is to find incentives for business, to get big countries behind solar+, the idea David King is working on – combining renewables and efficiency, with back-up where it’s needed.”

Professor Lovins told the conference: “Business-as-usual is going to get really ugly. What’s the narrative we can produce to compete with neo-liberalism?” – Climate News Network

Pre-history proof of climate’s see-saw sensitivity

The woolly rhinoceros once roamed wild on the plains of Europe Image: Public Library of Science via Wikimedia Commons
The woolly rhinoceros once roamed wild on the plains of Europe
Image: Public Library of Science via Wikimedia Commons

By Tim Radford

Computer simulations reaching back deep into the last Ice Age have enabled scientists to put a historic perspective on how even small variations in the climate system can lead to dramatic temperature change.

LONDON, 24 August, 2014 − It doesn’t take much to change a planet’s climate – just a little shift in the Northern hemisphere glacial ice sheet and a bit more carbon dioxide in the atmosphere. After that, the response is rapid. The tropical rain belt moves north and the southern hemisphere cools a bit, in some sort of bipolar see-saw response.

Sound familiar? It does, and it doesn’t. It all happened long before the internal combustion engine, or even the new Stone Age.

Researchers from the Alfred Wegener Institute’s Helmholtz Centre for Polar and Marine Research, Bremerhaven, the University of Bremen, Germany, and the University of Cardiff in the UK, report in Nature journal that they have made climate simulations that agree with observations of historical climate change that date back 800,000 years.

Long before the present alarms about global warming through the emission of carbon dioxide from fossil fuels, climate researchers were puzzled by the phenomenon of the Ice Ages and the “interglacials” that punctuated those long periods when the Arctic ice extended from the North Pole to the Atlantic coast of France, and over huge tracts of North America.

Vanished species

Mysteriously, and at great speed, the temperatures would rise by up to 10°C and the vast walls of ice would retreat. Lion, hyena and rhinoceros would invade the wild plains of what is now southern England, and now-vanished species of humans would hunt big game and gather fruit and seeds in the valleys and forests of Europe and America.

Since the end 10,000 years ago of the last ice age – itself a very rapid event – was the springboard for agriculture and civilisation, and eventually an Industrial Revolution based on fossil fuels, the story of climate change plays a powerful role in human history.

So any analysis of the tiny shifts in ice cover that seemed to trigger these dramatic, bygone events can be helpful in understanding the long story of the making of the modern world.

The researchers found a tentative scenario involving weak ocean currents, and prevailing winds that shifted the sea ice and allowed the oceans and atmosphere to exchange heat, pushing warmer water into the north-east Atlantic.

These changes precipitated a dramatic warming of the northern hemisphere in just a few decades, and the retreat of the glaciers for an extended period before the ice returned to claim much of the landmass again. But, overall, such changes tended to occur when sea levels reached a certain height.

“The rapid climate changes known in the scientific world as Dansgaard-Oeschger events were limited to a period of time from 110,000 to 23,000 years before the present,” said Xu Zhang, the report’s lead author.

“The abrupt climate changes did not take place at the extreme low sea levels, corresponding to the time of maximum glaciations 20,000 years ago, or at high sea levels such as those prevailing today. They occurred during periods of intermediate ice volume and intermediate sea levels”

Climate swings

Co-author Gerrit Lohmann, who leads the Wegener Institute’s palaeoclimate dynamics group, said: “Using the simulations performed with our climate model, we were able to demonstrate that the climate system can respond to small changes with abrupt climate swings.

“At medium sea levels, powerful forces − such as the dramatic acceleration of polar ice cap melting − are not necessary to result in abrupt climate shifts and associated drastic temperature changes.”

How much this tells anybody about modern climate change is open to debate. Right now, according to this line of evidence, the planet’s climate could be in one of its more stable phases of the Earth’s history.

But while the conditions for the kind of rapid change recorded in pre-history do not exist today, Prof Lohmann warns that “sudden climate changes cannot be excluded in the future”. – Climate News Network

Antarctic warming could accelerate sea level rise

Warming would cause more Antarctic ice to break off and melt Image: PIK/R.Winkelmann
Rising concern: warming would cause more Antarctic ice to break off and melt
Image: PIK (R.Winkelmann)

By Alex Kirby

An international study says warming is affecting not only the Arctic but also the Antarctic – and that could significantly raise global sea levels much faster than previously predicted.

LONDON, 20 August, 2014 − The effect of climate change on the world’s two polar regions looks like a stark contrast: the Arctic is warming faster than most of the rest of the Earth, while most of Antarctica appears to remain reassuringly locked in a frigid embrace.

But an international scientific team says the reality is quite different. The Antarctic is warming too, it says, and the southern ice could become the main cause of global sea level rise during this century − far sooner than previously thought.

The study, led by the Potsdam Institute for Climate Impact Research (PIK) in Germany, found that ice discharge from Antarctica could contribute up to 37 centimetres to global sea levels by 2100.

Computer simulations

The study is the first comprehensive estimate of the full range of Antarctica’s potential contribution to global sea level rise based on physical computer simulations. It combines state-of-the-art climate models and observational data with various ice models.

The results of the study − published in the European Geosciences Union’s journal, Earth System Dynamics − reproduce Antarctica’s recent contribution to sea level rise, as observed by satellites over the last two decades.

“If greenhouse gases continue to rise as before, ice discharge from Antarctica could raise the global ocean by an additional 1 to 37 centimetres this century,” says the study’s lead author, Anders Levermann, PIK professor of dynamics of the climate system.

“Science needs to be clear about the uncertainty,
so that decision-makers can consider the potential implications . . .”

“This is a big range – which is exactly why we call it a risk. Science needs to be clear about the uncertainty, so that decision-makers on the coast and in coastal mega-cities like Shanghai or New York can consider the potential implications in their planning processes.”

The scientists analysed how rising global average temperatures resulted in a warming of the ocean around Antarctica, influencing the melting of the Antarctic ice shelves.

Antarctica currently contributes less than 10% to global sea level rise and is a relatively minor player in comparison with the impact of the oceans’ increasing thermal expansion and the melting of glaciers.

But the major contributors to future long-term sea level rise are expected to be the huge volumes of ice locked up in Greenland and the Antarctic ice sheets. The marine ice sheets in West Antarctica alone could raise sea level by several metres over a period of several centuries.

The study’s computed projections for this century’s sea level contribution are significantly higher than the upper end of the latest projections by the Intergovernmental Panel on Climate Change. These suggest a probable rise by 2100 of around 60cm, although other estimates put the figure almost twice as high.

Even if governments can agree and enforce strict climate policies limiting global warming below the international target level of a maximum 2°C increase, Antarctica’s contribution to global sea level rise is expected still to range from 0 to 23cm this century.

Critical input

A co-author of the study, Robert Bindschadler, from the NASA Goddard Space Flight Center, said: “This paper is a critical input to projections of possible future contributions of diminishing ice sheets to sea level by a rigorous consideration of uncertainty of not only the results of ice sheet models themselves but also the climate and ocean forcing driving the ice sheet models.

“Billions of dollars, euros, yuan, etc, are at stake, and wise and cost-effective decision-makers require this type of useful information from the scientific experts.”

But major modeling challenges still remain. Datasets of Antarctic bedrock topography, for instance, are still inadequate, and some physical processes of interaction between ice and ocean cannot yet be sufficiently simulated.

The team also emphasises that the study’s results are limited to this century, while all 19 of the comprehensive climate models used show that the impacts of atmospheric warming on Antarctic ice shelf cavities will hit with a time delay of several decades.

However, Levermann says: “Earlier research indicated that Antarctica would become important in the long term. But pulling together all the evidence, it seems that Antarctica could become the dominant cause of sea level rise much sooner.” − Climate News Network

Canada puts oil exploitation before forests

A plane drops a water bomb on a forest fire in Ontario, Canada Image: {Per via Wikimedia Commons
A plane drops a water bomb on a forest fire in Ontario, Canada
Image: Per via Wikimedia Commons

By Paul Brown

Having repudiated the Kyoto Protocol on reducing fossil fuel use, Canada is still exploiting tar sands for oil − despite accepting that climate change is destroying its forests.

LONDON, 9 August, 2014 − Detailed evidence that Canada’s vast natural areas are undergoing major changes because of climate change is produced in a new report by Natural Resources Canada.

The government body describes problems with disappearing glaciers, sea level rise, melting permafrost and changing snow and rainfall patterns. One of the country’s most important natural resources, the forests that cover more than 50% of its land area, is under pressure because of pests, fire and drought.

There may, the reports says, be some pluses for Canada in climate change − at least in the short term − because some staple cereal crops will also be able to be grown further north because of warmer weather, assuming that the soil is suitable.

The report, Canada in a Changing Climate, concentrates on impacts and adaptation, but does not mention the causes, or the fact that Canada is now an international pariah in the environmental community because of its exploitation of tar sands for oil.

The country does attempt, for economic reasons, to be more energy efficient, but has repudiated the Kyoto Protocol and international efforts to curb fossil fuel use. The country had accepted a target of cutting emissions on 1990 levels by 5% by 2012, but the government backed out in 2011.

Highest emissions

Average greenhouse gas emissions for oil sands extraction and upgrading are estimated to be 3.2 to 4.5 times as intensive per barrel as for conventional crude oil produced in Canada or the US. If Alberta, where the oil is produced from tar sands, was a country and not a merely a province of Canada, it would have the highest per capita greenhouse gas emissions in the world.

The only mention the report makes of tar sands extraction is the problem caused by its large use of water, and it makes the point that the industry is recycling as much as possible.

A tar sands mine at Mildred Lake, Alberta Image: TastCakes/Janitzky via Wikimedia Commons
A tar sands mine at Mildred Lake, Alberta
Image: TastyCakes/Janitzky via Wikimedia Commons

Mitigation is not on the agenda, as the country’s politicians are intent on exploiting as much of the country’s oil and gas as possible.

A study of forests says that 224,410 people are directly employed in the sector, although it makes up only 1.1% of GDP. About 5% of the forests are damaged annually because of outbreaks of pests and fire. Temperatures in the forest areas have risen far more sharply than on the rest of the planet, with far-reaching consequences for the future, the report says.

In 2009, over three million hectares of forest were destroyed by fire in a single year. The number of fires is expected to increase, with the area being burned being three to five times as much in Western Canada by the end of the century. Large fires are raging again this year, but the quantity of the damage has yet to be assessed.

Severe outbreaks

One of the pests moving north and devastating mature trees is the mountain pine beetle. The beetle is endemic, but is killed by winter temperatures below minus 35˚C, thus limiting its numbers from year to year. However, winter temperatures in many areas now fail to drop below this level, leading to larger and more severe outbreaks of the pest.

A report in 2012 concluded that 18.1 million hectares of forest dominated by mature Lodgepole pine (Pinus contorta) had been affected. Scientists conclude that productivity of the forests will decline rapidly in British Columbia, and thousands of jobs will be lost. Meanwhile, the beetle is continuing to move north and east.

One advantage of the increased temperatures in Canada is that trees can grow further north and higher up mountains than previously, and there is a longer growing season.

Trees that live 100 years cannot migrate fast enough to take advantage, so local governments are going in for assisted migration.

This involves planting the seeds of suitable species 100 to 200 metres above the existing tree line on mountains, and in some cases two degrees of latitude northwards (about 100 miles) of the existing forests into what is currently tundra or scrub. – Climate News Network

Ignoring climate risks could sink US economy

Flood devastation after Hurricane Katrina hit Louisiana in 2005 Image: Infrogmation via Wikimedia Commons
Harsh reminder: devastation after Hurricane Katrina hit Louisiana in 2005
Image: Infrogmation via Wikimedia Commons

By Alex Kirby

Failure to factor immediate action on climate change into American policies and business plans aimed at economic prosperity will lead to havoc, warns former US Treasury Secretary.

LONDON, 3 August, 2014 − For the second time in a month, Americans have been warned that the economic cost of not acting on climate change is likely to be calamitous.

Robert Rubin, the co-chairman of the influential, non-partisan Council on Foreign Relations, says the price of inaction could be the US economy itself.

Writing in the Washington Post, Rubin, a former US Treasury Secretary, argues: “When it comes to the economy, much of the debate about climate change − and reducing the greenhouse gas emissions that are fuelling it − is framed as a trade-off between environmental protection and economic prosperity,

“But from an economic perspective, that’s precisely the wrong way to look at it. The real question should be: ‘What is the cost of inaction?’”

Widespread disruption

He backed the Risky Business Project, a research initiative chaired by a bi-partisan panel and supported by him and several other former Treasury Secretaries. It reported in June that the American economy could face significant and widespread disruption from climate change unless US businesses and policymakers take immediate action.

In his opinion article in the Washington Post, Rubin argues that, in economic terms, taking action on climate change will prove far less expensive than inaction. He wrote: “By 2050, for example, between $48 billion and $68 billion worth of current property in Louisiana and Florida is likely to be at risk of flooding because it will be below sea level. And that’s just a baseline estimate; there are other scenarios that could be catastrophic.

“Then, of course, there is the unpredictable damage from superstorms yet to come. Hurricane Katrina and Hurricane Sandy caused a combined $193 billion in economic losses; the congressional aid packages that followed both storms cost more than $122 billion.

“And dramatically rising temperatures in much of the country will make it far too hot for people to work outside during parts of the day for several months each year − reducing employment and economic output, and causing as many as 65,200 additional heat-related deaths every year.”

Rubin believes a fundamental problem with tackling climate change is that the methods used to gauge economic realities do not take climate change into consideration. He wants climate-change risks reflected accurately, and companies required to be transparent in reporting vulnerabilities tied to climate.

“If companies were required to highlight their exposure to climate-related risks, it would change investor behaviour, which in turn would prod those companies to change their behaviour,” he argues.

Flawed picture

“Good economic decisions require good data. And to get good data, we must account for all relevant variables. But we’re not doing this when it comes to climate change − and that means we’re making decisions based on a flawed picture of future risks.

“While we can’t define future climate-change risks with precision, they should be included in economic policy, fiscal and business decisions, because of their potential magnitude.”

Rubin says the scientific community is “all but unanimous” in agreeing that climate change is a serious threat. He insists that it is a present danger, not something that can be left to future generations to tackle.

“What we already know is frightening, but what we don’t know is more frightening still,” he writes. “For example, we know that melting polar ice sheets will cause sea levels to rise, but we don’t know how negative feedback loops will accelerate the process. . . And the polar ice sheets have already started to melt.”

He concludes: “We do not face a choice between protecting our environment or protecting our economy. We face a choice between protecting our economy by protecting our environment − or allowing environmental havoc to create economic havoc.”

The White House’s Council of Economic Advisers  has estimated that the eventual cost of cutting greenhouse gas emissions will increase by about 40% for every decade of delay, because measures to restrict them will be more stringent and costlier as atmospheric concentrations grow. − Climate News Network

Bold pathways point to a low-carbon future

Brighter future? Sunrise over a wind farm in the Cambridgeshire Fens, UK Image: David Clare/Climate News Network
Brighter future? Sunrise over a wind farm in the Cambridgeshire Fens, UK
Image: David Clare/Climate News Network

By Alex Kirby

The positive message from a scientific report for the UN Climate Summit is that the tough task of cutting CO2 emissions to limit global temperature rise to below 2°C is definitely achievable by following a set of bold, practical steps.

LONDON, 11 July 2014 − Scientists often hesitate to give a cut-and-dried, yes-or-no answer when asked how serious climate change is going to be, and whether the world can still escape significant damage.

Surprisingly, perhaps, a report prepared for a UN conference in September is unequivocal. Yes, it says − the worst is not bound to happen.

The good news is that the world can keep climate change within what are thought to be acceptable limits. The less good news is that while it is possible, it certainly won’t be easy.

The report shows how the countries that emit the most greenhouse gases (GHGs) can cut their carbon emissions by mid-century to prevent dangerous climate change. Prepared by independent researchers in 15 countries, it is the first global co-operation to identify practical pathways to a low-carbon economy by 2050.

The Deep Decarbonisation Pathways Project (DDPP) report is an interim version prepared for the UN Climate Summit to be held in New York on 23 September. The full DDPP report will be ready in the spring of 2015.

Dangerous change

The UN Secretary-General, Ban Ki-Moon, said the report tried to show how countries could help to achieve the globally-agreed target of limiting temperature rise to below 2°C. “Ambitious national action is critical to averting dangerous climate change,” he said. “This report shows what is possible.”

The report aims to help countries to set bold targets in the run-up to the UN climate talks to be held in Paris in 2015.

The work is led by the Sustainable Development Solutions Network (SDSN), an initiative of Columbia University’s Earth Institute for the UN, and the Institute for Sustainable Development and International Relations (IDDRI), a policy research institute based in Paris.

Jeffrey Sachs, the director of the SDSN, said the world had committed itself to limit warming to below 2°C, but not to practical ways of achieving that goal.

He said: “This report is all about the practicalities.  Success will be tough – the needed transformation is enormous – but is feasible, and is needed to keep the world safe for us and for future generations.”

“The issue is to convince the world that the future is as important as the present”

Fatih Birol, chief economist of the International Energy Agency, said: “The issue is to convince the world that the future is as important as the present. Paris 2015 may well be our last hope.”

Despite the global agreement to stay below 2°C, the world is on a path that, without action, will lead to an increase of 4°C or more. The Intergovernmental Panel on Climate Change said in its Fifth Assessment Report, known as AR5, that such a rise might exceed the world’s ability to adapt.

It said that a 4°C rise could endanger harvests and cause drastic sea-level rise, spread of diseases, and the extinction of ecosystems.

Some leading climate scientists − including NASA’s former chief climate scientist, Professor James Hansen, who is now at Columbia University − say that even a 2°C rise would be very dangerous. But many politicians regard it as an essential commitment.

The 15 national pathways examined in the report all show the importance of three factors for achieving radically lower carbon emissions.

The first is greatly increased efficiency and conservation in all energy use.

Renewable sources

The second factor is taking the carbon out of electricity by using renewable sources, “such as wind and solar, as well as nuclear power, and/or the capture and sequestration of carbon emissions from fossil-fuel burning”.

Nuclear energy still attracts widespread and determined opposition, and carbon capture and sequestration (trapping CO2 emissions and storing them underground or beneath the sea floor) has not yet proved that it can work on a commercial scale.

The third factor involves replacing fossil fuels in transport, heating and industrial processes with a mix of low-carbon electricity, sustainable biofuels, and hydrogen.

The authors say their interim report shows the critical long-term importance of preparing national deep decarbonisation plans for 2050.

Emmanuel Guerin, the DDPP’s senior project manager, said the pathways were crucial to shaping the expectations of countries, businesses and investors. − Climate News Network

Climate puts US at risk of multi-billion bill

Overheating: US crops such as cotton face a %20 drop in yield Image: Wars via Wikinmedia Commons
Overheated economy: US crops such as cotton face a 20% drop in yield
Image: Wars via Wikimedia Commons

By Alex Kirby

A study of the possible cost of climate change to the US economy warns government and business that billions of dollars could be at risk through damage to property, reduced harvests and workers incapacitated by extreme heat.

LONDON, 29 June, 2014 − The sheer economic cost of climate change to Americans could be far greater than many realise, an influential study says.

The study was commissioned by the Risky Business Project, a research organisation chaired by a bi-partisan panel and supported by several former US Treasury Secretaries.

It expects climate change to have varied impacts across different regions and industries. Rising sea levels, it says, could destroy many billion dollars’ worth of coastal properties by 2050, and warming temperatures, especially in the south, south-west and mid-west, could cut the productivity of people working outdoors by 3%.

Without a change in crops, harvests in these regions could fall by 14%. But further north, in states such as North Dakota and Montana, winter temperatures will probably rise, reducing frost and cold-related deaths and lengthening the growing season for some crops.

Kate Gordon, executive director of the Risky Business Project, said : “We still live in a single integrated national economy, so just because it’s not hot where you are doesn’t mean you won’t feel the heat of climate change.”

Michael Bloomberg, a former mayor of New York, said: “Damages from storms, flooding, and heat waves are already costing local economies billions of dollars. We saw that firsthand in New York City with Hurricane Sandy.

Costs of inaction

“With the oceans rising and the climate changing, the Risky Business report details the costs of inaction in ways that are easy to understand in dollars and cents − and impossible to ignore.”

Hank Paulson, a former Treasury Secretary and co-chair of the Risky Business Project, said the report shows us that “our economy is vulnerable to an overwhelming number of risks from climate change.

“But if we act immediately, we can still avoid most of the worst impacts of climate change and significantly reduce the odds of catastrophic outcomes. But the investments we’re making today will determine our economic future.”

In a section on short-term climate threats, the authors say: “The American economy is already beginning to feel the effects of climate change. These impacts will likely grow materially over the next 5 to 25 years…”

“Just because it’s not hot where you are doesn’t mean
you won’t feel the heat of climate change”

They say there is a 1-in-20 chance of yield losses of more than 20% in corn, wheat, soya and cotton crops over that timespan.

On energy, they say changes in temperature driven by greenhouse gases will probably mean a need to build roughly 200 average coal-fired or natural gas-fired power plants between 2020 and 2045, costing up to $12 billion per year.

Climate impacts, the report says, are unusual because future risks are directly tied to present decisions. By failing to lower greenhouse gas emissions today, decision-makers put in place processes that increase overall risks tomorrow.

By 2050, on present trends, $66bn-$106bn worth of existing coastal property will probably be below sea level nationwide, with $238-$507bn worth by 2100.

By mid-century, the average American will probably see 27 to 50 days over 95°F (35°C) each year − two to more than three times the average annual number of such days seen over the last 30 years. By the end of the century, this number will probably average 45 to 96 days over 95°F each year.

But the study says that the south-west, south-east, and upper mid-west will probably see several months of 95°F days annually.

Human threshold

In the longer term, extreme heat during parts of the year could pass the threshold at which the human body can no longer maintain a normal core temperature without air conditioning. At these times, anyone who has to work outdoors, or without access to air conditioning, will face severe health risks and possible death.

The authors say they hope it will become standard practice for the American business and investment community to factor climate change into its decision-making process. They say: “We are already seeing this response from the agricultural and national security sectors; we are starting to see it from the bond markets and utilities as well.

“But business still tends to respond only to the extent that these risks intersect with core short-term financial and planning decisions.”

And the authors warn the government: “We also know that the private sector does not operate in a vacuum, and that the economy runs most smoothly when government sets a consistent policy and a regulatory framework within which business has the freedom to operate.

“Right now, cities and businesses are scrambling to adapt to a changing climate without sufficient federal government support…” − Climate News Network

Underworld threat to melting icecap

 

Concealed beneath the Petermann glacier are towering blocks of ice Image: Michael Studinger/NASA via Wikimedia Commons
Concealed beneath the Petermann glacier are towering blocks of ice
Image: Michael Studinger/NASA via Wikimedia Commons

By Tim Radford

Radar images of Greenland’s glaciers have revealed a spectacular underground landscape of “skyscraper” ice blocks created by a melt-and-freeze cycle that is accelerating the reduction of the icecap

LONDON, 16 June − Researchers in the US have identified a new reason for the acceleration in the melting of Greenland’s icecap − the ice underneath, as it melts and then refreezes, appears to speed up glacial flow.

The melt-and-freeze-again cycle is not itself new, as a similar process has been diagnosed under the ice cap of Antarctica. Nor is the process itself necessarily connected with global warming. Such things must always have happened.

But Robin Bell, a geophysicist at Columbia University’s Lamont Doherty Earth Observatory, reports with colleagues in Nature Geoscience that they used ice-penetrating radar to identify ragged blocks of ice as tall as skyscrapers and as wide as the island of Manhattan at the very bottom of the ice sheet. These structures cover about a tenth of the island and seem to form as melted water below the ice freezes again. They then warp the ice around and above them.

Easier to flow

“We see more of these features where the ice sheet starts to go fast,” Professor Bell said. “We think the refreezing process uplifts, distorts and warms the ice above, making it softer and easier to flow.”

Bell and her colleagues looked at the Petermann Glacier in Greenland’s north, which in 2010 pushed a huge chunk of ice into the sea. Observations suggest that the glacier is moving twice as fast as the surrounding ice, and the hypothesis is that the melt-and-freeze-again process is contributing to this acceleration.

Researchers have been troubled for a decade or more by the apparent increase in ice loss from Greenland. Were the whole island to melt, sea levels worldwide would rise by more than seven metres, so the concern is practical.

Recently, researchers have found that the bedrock beneath many glaciers is actually below sea level, making the glaciers vulnerable from ocean inflow. They have identified a process called “dynamic thinning”, triggered by warmer air temperatures, and they know anyway that natural geothermal heat flow mis likely to melt the base of the ice and lubricate any acceleration.

They have measured a fourfold increase since 1997 in summer flow speeds in the island’s Jakobshavn glacier. And they have indicated that the Greenland icecap each summer becomes more vulnerable to melting because the snows themselves are becoming darker, as more dust blows in from areas that are increasingly ice free.

Ice slide

So the discovery of a process that will make the ice slide to the sea more efficiently is not of itself more sinister. The meltwater could come from a number of sources. The friction created by a glacier as it moves must contribute. So could natural heat flow from the bedrock. Surface ice could melt in the summer sun and drain through crevasses to the base.

However, what the discovery helps to offer, literally and metaphorically, is a deeper understanding of the processes at work below the ice.

What is not clear is whether the melt-and-freeze cycle will influence the rate at which ice is lost in future. Nor does anyone yet know what triggers the cycle.

“The conditions under which such switches occur should be investigated, as they directly affect the ability of an ice sheet to slide over its bed,” advises Joseph A. McGregor, of the University of Texas at Austin, writing in the same issue of Nature Geoscience. − Climate News Network