Warning signs

The foreports are extracts from the Sydney Morning Herald. All dates are included.


Warning of global anarchy

February 24th, 2004

A secret report prepared by the Pentagon warns that climate change may lead to global catastrophe costing millions of lives and is a far greater risk than terrorism, a British weekly has said.

The report was ordered by an influential US Pentagon adviser but was covered up by "US defence chiefs" for four months, until it was "obtained" by The Observer.

The leak promises to draw angry attention to US environmental and military policies, following Washington's rejection of the Kyoto Protocol on climate change and President George Bush's scepticism about global warning - a stance that has stunned scientists worldwide.

The Pentagon report, commissioned by Andrew Marshall, predicts that "abrupt climate change could bring the planet to the edge of anarchy as countries develop a nuclear threat to defend and secure dwindling food, water and energy supplies", The Observer said.

The report, quoted in the paper, concluded: "Disruption and conflict will be endemic features of life ... Once again, warfare would define human life."

Its authors - Peter Schwartz, a CIA consultant and former head of planning at Royal Dutch/Shell Group, and Dough Randall of Global Business Network based in California - said climate change should be considered "immediately" as a top political and military issue.

It "should be elevated beyond a scientific debate to a US national security concern", they were quoted as saying.

Experts familiar with the report told the newspaper the threat to global stability "vastly eclipses that of terrorism".

Some examples given of probable scenarios in the dramatic report include:

Britain will have winters similar to those in Siberia as European temperatures drop off radically by 2020.

By 2007, violent storms will make large parts of the Netherlands uninhabitable and lead to a breach in the aqueduct system in California that supplies all water to densely populated southern California.

"Catastrophic" shortages of potable water and energy will lead to widespread war by 2020.

Coming from the Pentagon, normally a bastion of conservative politics and focused on military and political strategy, the report is expected to bring environmental issues to the fore in the US presidential race.




World's Achilles heels

October 26th, 2004

When the world warms, key ecosystems may be tipped out of balance, creating a whole new set of climatic challenges. Ian Sample explains where the dangers lie.

Cast an eye over the many forests' worth of scientific literature on global warming, and it becomes clear that working out what a temperature rise of a few degrees will mean for life anywhere on the planet is far from straightforward.

Vast icesheets may melt, sea levels will rise and, faced with a new climate, species will have to adapt, move or perish. Yet the precise details of how any of it will happen are unknown.

Now it seems the future has become even more uncertain. Climate scientists say they have identified a dozen weak links around the world - regions where global warming could bring about the sudden collapse of vital ecosystems, the effects of which will be felt far afield.

An abrupt halt in one ocean current could devastate Antarctic fish stocks; disruption to another could make temperatures in Europe plunge. When rains return to the Sahara, disease and crop damage from pests could soar.

Meanwhile, a drier Amazon will trigger dieback of the forests, threatening many species with extinction. Losing the forests will itself exacerbate global warming.

Scientists noted last week that we might have less time to combat global warming than we thought. Measurements taken in Hawaii show atmospheric carbon dioxide levels have risen sharply, and inexplicably, in the past two years. Although it is too early to confirm a definite upward trend, the results came as an unwelcome surprise.

John Schellnhuber, the research director at the Tyndall Centre for Climate Change Research in Britain, played a key role in identifying the dozen systems where global warming could produce sudden and dramatic environmental damage. He calls them the "tipping points" - the Achilles heels of the planet.

At a conference earlier this year, Schellnhuber and other scientists called for a concerted global effort to investigate the Earth's known tipping points and to search for new ones. Only then, he said, would we be able to identify where the consequences would be felt first.

"It'll take a global effort to understand these, and we have to make sure that none are activated through human actions," he says.

Amazon forest

The size of Western Europe, the Amazon forest is one of the most biodiverse regions on Earth. Models suggest that, with global warming, will come a drop in Amazonian rainfall, leading to the gradual death of the forest and subsequent collapse of the myriad ecosystems it supports.

As the trees die off, they will fall and rot, releasing carbon dioxide. In the worst-case scenario, the quantities of carbon dioxide emitted could be similar in magnitude to the 20th century's total fossil fuel output.

The monsoon

During March and April, the Indian subcontinent begins to heat up. The hot land produces a sharp temperature gradient between the land and sea that causes an abrupt reversal of the winds from seaward to landward.

As the winds strike the Himalayas and are deflected upwards, they create a low pressure system, forcing rain clouds to release their stores of water. While the monsoon season can cause incredible flood damage, local populations are largely adapted to, and to some extent reliant on, the weather.

If global warming has the expected effect of heating India even more, the monsoon season could become far more severe.

However, pollution in the region could make rain droplets smaller, diminishing overall rainfall. Pollution can also increase the reflectivity of clouds, preventing the ground heating up so much. These factors would weaken the monsoon, causing havoc for Indian agriculture, with serious consequences for food production.

Methane clathrates

Deep within the Siberian permafrost and ocean floor sediments lie vast deposits of gas-filled ice called methane clathrates. At Siberian temperatures, or under the weight of icy oceans, the clathrates are stable. But as global warming takes effect, the icy crystals that clutch the gas could rupture, releasing it into the oceans and atmosphere.

According to the United States Geological Survey, some 10 trillion to 11 trillion tonnes of carbon are locked up in clathrates in ocean floor deposits, the equivalent of 20 times the known reserves of natural gas.

If released into the atmosphere, methane from the clathrates could exacerbate global warming by up to 25 per cent.

Tibetan plateau

Spanning a quarter of China's huge land mass is the Tibetan plateau. Because the region is permanently under snow and ice, it acts like a giant mirror, reflecting the sun's rays back into space.

The effect is to keep a lid on global warming, at least locally, as the darker soils are unable to bask in the sun's radiation and increase in temperature.

In a warmer world, the white of the Tibetan plateau will slowly turn to brown and grey as the snow retreats to reveal the ground beneath. As the ground warms, melting will accelerate. Tibet will become a much warmer place.

North Atlantic current

The North Atlantic current is one of the strongest ocean currents in the world.

It works like a conveyor belt. Surface water in the North Atlantic is first cooled by westerly winds from North America, making the water denser and saltier so it sinks to the ocean floor before moving towards the equator. Driven by winds and replacing the cold water moving south, warm water from the Gulf of Mexico moves upward into the Atlantic.

The effect of the current on climate is dramatic. It brings to Europe the equivalent of 100,000 large power stations' worth of free heating, propping up temperatures by more than 10C in some parts.

Global warming could change all that, though not quickly. Computer models predict that as global warming increases, so will rainfall in the North Atlantic. Gradually the heavier rains will dilute the sea water and make it less likely to sink, a process that could eventually bring the whole conveyor to a halt.

"It won't happen in a matter of weeks, like in the movie The Day After Tomorrow, but it could happen over a few decades," Schellnhuber says.

In the past 50,000 years, the current has stopped at least seven times. Collapse of the North Atlantic current would hit Iceland, Scotland and Norway the hardest; temperatures there could drop 10C or more.

Ozone hole

"In a sense, this is the mother of all tipping points, and it's one that has been activated already," says Schellnhuber.

Scientists now generally agree that global warming may drastically amplify the power of ozone-destroying chemicals, which linger in the stratosphere for decades. At high altitude, ozone acts as a shield against the sun's damaging radiation. Global warming, while heating the lower atmosphere, can lead to cooling in the stratosphere where the ozone layer forms. Cooling this band of air has a complex knock-on effect, disrupting a chemical process that prevents ozone from breaking down. The result is a loss of ozone, increasing the risk of skin cancer and blindness. Although the ozone hole is often associated with Antarctica and Australia, ozone loss because of global warming could lead to holes over other parts of the world.

West Antarctic icesheet

The giant West Antarctic icesheet won't melt in the near future - the ice is up to a kilometre thick - but two years ago a vast chunk, the Larsen B iceshelf, broke off the eastern side of the Antarctic peninsula and fragmented into icebergs. In just 35 days, about 3250 square kilometres of ice were lost. The shelf is now roughly 40 per cent of the size at which it had previously stabilised.

Some predict that the rest of the sheet could feel the force of global warming quickly. Should the entire sheet melt, it is estimated the sea level around the world would rise by more than six metres.

Salinity valves

In some parts of the world, local geography conspires to pinch the waters between adjacent seas into separate bodies of water. If one is saltier than the other, a flux of salt, nutrients and oxygen can be set up across the gap, producing what scientists refer to as a salinity valve.

Probably the most significant salinity valve is the Strait of Gibraltar, acting as a pinch between the Mediterranean and the North Atlantic Ocean. The areas around the valves give rise to unique ecosystems that are highly adapted to local conditions.

"Everything is in a balance now - all the ecosystems have adapted to a certain salinity," Schellnhuber says. If conditions around salinity valves change rapidly, he says, those ecosystems may not be able to adapt quickly enough to survive.

El Nino

The disruption caused by El Nino is well known, from droughts in Asia and Australia to flooding in regions such as Ecuador and northern Peru. Spanish for "the boy child", the term El Nino was originally used to describe a warm ocean current that arrived around Christmas time. Nowadays it refers to a general warming of the central and Asian Pacific, which causes a major shift in weather patterns.

El Ninos are already somewhat erratic, occurring every two to seven years, but some models say global warming may make these events not only more severe but more frequent.

The impact on agriculture and food production could be serious. Indonesia, the Philippines, South-East Asia and eastern Australia could face damaging droughts, while the heavy rains and flooding could cause problems for the north-western regions of South America.

The Atlantic circumpolar current

Some scientists believe the Atlantic circumpolar current is the most significant on the planet. It swirls 140 million cubic metres of water around Antarctica every second, mixing water from the Pacific, Atlantic and Indian oceans as it goes. The current taps into another circulation that causes cold surface water to sink while warmer water rises, bringing with it vital nutrients from dead plankton and other marine life on the ocean floor.

Global warming is expected to produce more rainfall over the poles, which could slow the rise of nutrients for dispersal by the Atlantic circumpolar current. "For marine life, any change in the currents is extremely important," Schellnhuber says.

Greenland icesheet

The Greenland icesheet holds about 2.6 cubic kilometres of fresh water - about 6 per cent of the planet's supply. It is imperative that this water remains frozen. If global warming causes temperatures to rise by more than about 3C, Greenland is likely to begin a slow thaw, steadily releasing all that water - now resting on land - into the North Atlantic Ocean.

Climate models suggest that a temperature increase of about 8C could cause the Greenland icesheet to disappear almost entirely - a thaw that would lead to a seven-metre rise in the seven seas.

"If the Greenland icesheet goes, it probably will not come back for the next 60,000 years," Schellnhuber says.

The Guardian


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