Sea Level Rise // Current TV

Climate clock is ticking

To the twelfth hour.

From the article:

In the summer of 2007, a large portion of Arctic Sea ice - about 40 per cent - simply vanished. That wasn't supposed to happen. At least not yet. As recent as 2004, scientists had predicted it would take another 50 to 100 years for that much ice to melt. Yet here it was happening today.

It raised the question: Had global warming suddenly pressed the gas pedal to the floor? If so, the world was in for quite a climate ride - dramatic, jarring changes in climate much sooner than expected. Climate scientists were deeply worried.

"It really caught the scientific community by surprise," Professor James Ford, a McGill University geographer and Arctic expert recalled. "The Arctic system is close to crossing the threshold beyond which we will get dramatic changes in climate."

The sudden mass melting brought an earlier ice event into new perspective. In 2005, scientists at the Canadian Ice Service, the nation's leading ice specialists, were examining satellite images when they noticed that the Ayles Ice Shelf, which is about as big as the island of Montreal, had suddenly broken free from the top of Ellesmere Island and floated away.

Vincent Warwick, an Arctic expert at Université Laval, said at the time: "This is a dramatic and disturbing event. It shows that we are losing remarkable features of the Canadian North that have been in place for many thousands of years. We are crossing climate thresholds, and these may signal the onset of accelerated change ahead."

The ice melt of 2007 seemed to confirm Warwick's fears. Reports since then claim the Arctic ice could be gone by 2013.

We have already crossed some critical climate thresholds. The world not only has to drastically cut back its greenhouse gas emissions but also begin to take steps to deal with the inevitable changes that global warming will cause. The much-feared tipping points - which would cause massive icecap and ice shield melting, and plunge the world headlong into severe weather systems, causing broad devastation and rising seas - seem increasingly probable.

This is why, scientists say, the United Nations climate talks that began this week in Bonn, Germany, and will culminate in Copenhagen, Denmark, in December, are so important. They are a last chance for the world to come to its senses and negotiate an agreement to drastically cut greenhouse gas emissions.

Scientists have been warning about these tipping points for decades, but few politicians have listened. Most industrialized countries led by the United States, Canada, Australia and Europe have continued to pump increased amounts of GHGs into the atmosphere despite promises to reduce emissions below 1990 levels.

Developing countries like China and India have taken no steps to curtail their emissions. With a new coal-fired power plant coming on stream every week, China is now the world's biggest GHG producer.

The atmosphere now contains 387 parts per million of carbon dioxide. This is more than the Earth has seen in the last 650,000 years. Pre-industrial levels were about 270 ppm, which remained pretty well constant over the 100,000 years mankind has walked the Earth. Scientists say that because of a delayed reaction, we have yet to experienced the full effect of what we already have put into the atmosphere. That effect will unravel in the decades to come. Meanwhile, we're adding about 30 billion tonnes of CO2 into the atmosphere annually or about 2 ppm. Last year alone, global GHGs increased three per cent.To the twelfth hour. From the article: In the summer of 2007, a large portion of... more

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India's climate refugees forced to fight- here and now

Make no mistake about it, climate change is affecting real people now. They may not be... more

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The world's first climate change refugees: Papua New Guinea

So now it begins. Papua New Guinea, Tuvalu, Kiribati, the Maldives, Vanuatu... Names... more

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Sea levels rising twice as fast as predicted

Sea levels around the world are predicted to rise by up to a metre by the end of the... more

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Poor communities get help with climate adaptation:floating gardens

It is unfortunately a given now that certain areas of the world, Bangladesh for... more

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Antarctic glaciers melting faster than thought

These scientists claim we have six years to get our act together. All I can say to... more

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Moving to higher ground

The Ross Ice Shelf in West Antarctica is the size of France. It's weak... more

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Rising sea salinates India's Ganges river

This entire area of the world that includes India, Bangladesh, Sri Lanka, the... more

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The Maldives: trouble in paradise

Rising seas are threatening to engulf the Maldives, so the president wants to buy a... more

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Bangladesh: where warming hits hard

Of all of the effects of climate change, sea level rise may pose the most pervasive challenge for Bangladesh. Nearly the entire country is a vast, flat delta, where even a modest climb in the height of the Bay of Bengal could push water deep inland if it weren't for the protective barriers along the coast.

After being fairly stable for a couple of thousand years, sea levels have crept up about 20 centimetres since the mid-1800s. For the coming century, the 2007 IPCC report talks about sea level rise in centimetres — to be precise, 18 to 59 centimetres. But most climate scientists agree these estimates are too conservative, as they overlook the ways glaciers and ice sheets can slip, crack and calve off icebergs to dump increasing amounts of ice into the oceans. Now that researchers are watching this happen and beginning to understand these processes, known as glacial dynamics, some are predicting much larger increases in sea levels.

We are nature's laboratory on disasters. We don't have volcanoes. But any other natural disaster you think of, we have it.

Ainun Nishat
To get a rough upper limit on how far sea levels could rise, glaciologist Tad Pfeffer of the University of Colorado at Boulder and colleagues recently calculated the effects of all the world's glaciers and ice sheets flowing at very high but plausible speeds. By 2100, they figured, sea levels are likely to rise by 0.8 metres, and possibly as much as 2 metres4.

But climatologist James Hansen of the NASA Goddard Institute of Space Studies, for one, argues that more extreme changes could be in store. Hansen says it is possible that continuing to burn fossil fuels at current rates would raise sea level several metres by the end of the century5, because seas have risen several metres per century in the ancient past while being warmed less rapidly than the ocean is by man-made greenhouse gases today.

"We don't really have an upper limit [on sea level rise], but we can talk about it sensibly in terms of likely magnitudes," says Richard Alley, a glaciologist at Pennsylvania State University. "No one really believes we can destroy an ice sheet in mere decades — at least centuries would be required based on what we know about ice flow." But with Pfeffer's estimates, "you probably have enough information to calibrate your fear of flooding," says Alley.

What is certain is that even if people stopped emitting greenhouse gases in the next few decades, Bangladesh would still be committed to coping with sea level rise for centuries3. But continuing 'business as usual' could make the situation much worse as major ice sheets disintegrate.Of all of the effects of climate change, sea level rise may pose the most pervasive... more

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Malibu's vanishing Broad Beach a sign of rising sea levels

People who deny the need for mitigation, will eventually have to live with adaptation.

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As ice melts, Antarctic bedrock is on the move

As ice melts away from Antarctica, parts of the continental bedrock are rising in... more

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Sea level rise could top 1.5m by 2099, experts warn

| Environment | guardian.co.uk

PHOTO: A breaking ice shelf in Antarctica ... many scientists fear the world is close to a tipping point. Jim Elliott/British Antarctic Survey/AP

Sea level rise due to global warming will "substantially exceed" official UN projections and could top 150cm by the end of the century, according to a report from the US Geological Survey on the risks of abrupt climate change. Such a rise would be catastrophic, seeing hundreds of millions of people affected by flooding.

Many scientists now fear the warming world is on the verge of "tipping points", in which climate change and its effects accelerate rapidly. The science is evolving quickly and the new report updates the most recent findings of the UN's Intergovernmental Panel on Climate Change (IPCC), which was released in 2007.

Some observers have called for an update of the science before the UN talks on a global deal on greenhouse gases emissions reach their finale in December 2009. The US report considers four scenarios for abrupt change, and delivers bad news on two.

On sea level, the report found models used by the IPCC in 2007 do not take into account recent information on how fast glaciers slide into the oceans, particularly from Greenland and the West Antarctic ice sheets. The report says the south western states of the US will enter a "permanent drought state".

But the risk of the ocean circulation in the Altantic shutting down – freezing the coasts of America and Europe, as in the film The Day After Tomorrow – is rated as low by the report. It predicts a slowdown of around 25% to 30%. The chance of a catastrophic release of methane from frozen sub-sea stores at high latitudes is also rated low. The report is part of a series by the US Climate Change Science Program, which collates all US federal research on the subject. It was presented tonight at the American Geophysical Union meeting in San Francisco.

The IPCC predicted that sea level would rise by 28cm to 42cm by the end of the century. ,The authors cite a 2007 study by Prof Stephan Rahmstof at the Potsdam Institute for Climate Change Research which predicted a sea level rise of between 40cm-150cm by 2100. But even this much higher estimate will "likely need to be revised upwards" because it does not fully capture the ice flow processes.| Environment | guardian.co.uk PHOTO: A breaking ice shelf in Antarctica ... many... more

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India loses more people to climate change than any other country

I truly think that before we as a species can confront climate change effectively, we... more

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Bangladesh climate refugees search for higher ground

This is not happening in the near distant future. This is happening now. Where is the... more

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Floods under Antarctic ice speed glaciers into sea: study

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California ordered to prepare for sea-level rise

California Gov. Arnold Schwarzenegger on Friday ordered preparations for rising sea... more

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Five nations under threat from climate change

While the world dithers about tackling climate change, in some parts of the world people are running out of time. In Florida sea level rises can be worked around to some extent - condos can be put on stilts and moved away from the shoreline. But on some islands you can only move back so far before you have to start worrying about the water at your back door as well as the water in front.

Here are five islands whose inhabitants are going to need a new home soon:

1. The Guardian reports today that the new president of the Maldives will be putting part of the country's profits from tourism into a very special - and unusual - fund: one that will be used to buy a new, climate-change-friendly home. With its highest point reaching only 2.4 metres, the Maldives is one of the lowest-lying nations in the world and risks being submerged by rising sea-levels.

2. Tuvalu is another small pacific island state, and after the Maldives the second-lowest nation in the world. At its highest, it is 5 metres above sea-level and could be gone by the middle of this century. In 2002, the government was said to have hired two international law firms to look into suing polluting nations for effectively evicting its citizens.

3. Kiribati is a group of 32 atols and one island that peaks at 6.5 metres above sea-level. The World Bank has been involved in assessing the nation's vulnerability to climate change. I attended a talk by one of the project leaders some years ago in Paris. She quoted a few of the changes which the islanders were noticing. The one that has always stuck with me was "the first line of coconut trees has disappeared". Salt-intrusion was killing off the trees that were closest to the water.

4. The inhabitants of the Carteret Islands of Papua New Guinea may be among the first climate refugees - their home lies just 1.2 metres above the waves. The government of Papua New Guinea adopted a plan in 2005 to evacuate the locals to the neighbouring island of Bougainville. The relocation was initially scheduled for 2007, then delayed. According to this report, there was a trial earlier this year, which created some tension as relocated citizens were used as labourers in coconut plantations on Bougainville.

5. In 1995, 500,000 inhabitants on Bangladesh's Bhola Island were forced to move in when half their island was permanently flooded. Some claim they were the first climate refugees. Scientists predict that 20 million Bangladeshis could suffer the same fate by 2030.
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How many more will it take for urgent action to begin? The longer we wait the more CO2 and other greenhouse gases continue to be spewed into the atmosphere. I recall sitting here last year asking the same question, and still no global treaty on climate change that addresses the true urgency of this, nor any significant bills by this Congress. And Obama still touts the 80% by 2050 line as if we actually have that kind of time. We don't.While the world dithers about tackling climate change, in some parts of the world... more

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New NASA satellite study reveals melting of Alaskan glaciers

A NASA-led research team has used satellite data to make the most precise measurements to date of changes in the mass of mountain glaciers in the Gulf of Alaska, a region expected to be a significant contributor to global sea level rise over the next 50-100 years.

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Geophysicist Scott Luthcke of NASA's Goddard Space Flight Center, Greenbelt, Md., and colleagues knew from well-documented research that changes in the cryosphere glaciers, ice caps, and other parts of the globe covered year-round by ice -- are a key source of most global sea level rise.

Melting ice will also bring changes to freshwater resources and wildlife habitat. Knowing that such ice-covered areas are difficult to observe consistently, the team worked to develop a satellite-based method that could accurately quantify glacial mass changes across seasons and years, and even discern whether individual glacier regions are growing or shrinking.

The study's authors found that the annual ice mass lost from glaciers in the Gulf of Alaska has been 84 gigatons annually, about five times the average annual flow of the Colorado River through the Grand Canyon and equal to the entire amount of water in the Chesapeake Bay.

"The Gulf of Alaska region is 20 times smaller than the ice-covered area of Greenland, yet it contributes nearly half as much freshwater melt as Greenland and accounts for about 15 percent of present-day global sea level rise stemming from melting ice," said Luthcke, lead author of the study which will appear this week in the Journal of Glaciology. "Considering that the Gulf of Alaska makes such a disproportionate contribution, it is vital that we know more about the nature of glacial change there."

Luthcke and colleagues found a way to remotely measure the "mass balance" of a glacier; that is, the net annual difference between ice accumulation and ice loss. Past measurements of glacial mass balance in remote mountain ranges have been sparse or imprecise. Ground-based sensors can provide long-term data, but such data points are scattered due to the inaccessibility of many remote mountain ranges. Altimeters aboard aircraft can measure changes in the height of glaciers, but the sampling is sporadic because flights are relatively infrequent.

Glaciers in the coastal environments on the edge of the Arctic or Antarctic shed and gain mass rapidly, a high mass turnover that is particularly sensitive to climate change. Warming seas can accelerate the motion of tidewater glaciers, and melt water on glacial surfaces can flow to the floors of glaciers and serve as a lubricant as the ice slides toward the sea. The subsequent addition of freshwater to the ocean contributes to one of two sources of global sea level rise; "eustatic" rise resulting from melted ice in the form of freshwater, with the other source set off by "thermal expansion," sea level rise that occurs due to warming ocean temperatures.

The Goddard-led research team developed a new data analysis technique for NASA's Gravity Recovery and Climate Experiment (GRACE) mission. GRACE is made up of twin satellites that orbit Earth about 137 miles apart and 300 miles above Earth's surface. The positions of the two satellites change in response to variations in Earth's gravity field, which is stronger or weaker depending on the land or ice mass that they are flying over. Microwave ranging systems measure the distance between the two satellites down to the width of a human hair, so by measuring the change in the distance between the satellites over time, researchers can essentially "weigh" the changes in Gulf of Alaska glaciers.
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More precise methods of determining total ice accumulation and loss in this and other areas are now essential in crafting proper legislation to deal with this crisis.A NASA-led research team has used satellite data to make the most precise measurements... more

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