By the End of the Century...

Predicting the future is easy.  It's trying to figure out what's going on now that's hard.

- Fritz R S Dressler

World Habitats in Danger

London - A third of the world's habitat is under threat from global warming and could disappear or change beyond recognition by the end of the century, according to a World Wide Fund for Nature report.  In Russia, Canada and Scandinavia up to 70% of habitats could be lost, and in the United States much of the New England and New York state fir and spruce forests may be wiped out if carbon dioxide emissions are not reduced.

"This is not some slow, controlled change we're talking about.  It's fast, it's unpredictable and it's unprecedented during human civilisation," Adam Markham, a co-author of the report, said.  The study based its predictions on what its authors said was a "moderate" projection that carbon dioxide in the atmosphere would double from pre-industrial levels this century.

Mr Markham, director of the campaign group Clean Air - Cool Planet, and co-author Jay Malcolm, of Toronto University, used climate and vegetation models to map out the potential risk to biodiversity.  As global warming accelerated, plants and animals would be forced to find new habitats, Mr Markham said.  But the speed of climate change may mean many were not able to move and adapt fast enough.  "In some places plants would need to move 10 times faster than they did during the last ice age merely to survive," he said.

He noted that during the last ice age, 11,000 to 13,000 years ago, humankind with its infrastructure was not there to stand in the way of species migration, a factor which could threaten adaptation next time.  The report, Global Warming and Terrestrial Biodiversity Decline, said some species most at risk were Australia's mountain pygmy possum, the Ethiopian Gelada baboon and the monarch butterfly which winters in Mexico. - Reuters

Source: International page The Dominion Sep 2000

Killer Heatwaves Predicted by UN

The Hague - Deaths from heatwaves in big cities are expected to double over the next two decades if nothing is done to curb global warming, says the United Nations weather agency.  "Heatwaves are expected to become a major killer," said Godwin Obasi, Secretary-General of the World Meteorological Organisation.  Small increases in global temperatures owing to growing amounts of "greenhouse gases" were amplified in big cities, he said yesterday.

Obasi said that in the 15 biggest United States cities, an average of 1,500 people collapsed and died from heatwaves each year, a significant increase over the past decade.  The death toll from heatwaves in those cities was expected to balloon to 3,000 or 4,000 by 2020, he said.  Burgeoning deaths from heat were also expected in other cities around the world, including Toronto, Shanghai, Athens and Madrid. - Reuters

Source: NZ Herald Thursday 23 November 2000

Yes, Virginia, there is a global warming

Source: Funny Times October 2000

Climate Change: A Canary in a Coal Mine?

The Arctic Seems to Be Getting Warmer.  So What?

"Climate change in the Arctic is a reality now!"  So insists Robert Corell, an oceanographer with the American Meteorological Society.  Wild-eyed proclamations are all too common when it comes to global warming, but in this case his assertion seems well founded.  Dr Corell heads a team of some 300 scientists who have spent the past 4 years investigating the matter in a process known as the Arctic Climate Impact Assessment (ACIA).  The group, drawn from the 8 countries with territories inside the Arctic Circle, has just issued a report called "Impacts of a Warming Arctic", a lengthy summary of the principal scientific findings.  A second report, which will sketch out recommended policies, is due out in a few weeks.  A third, far heftier tome detailing all the scientific findings will not come out for some months yet.

Already, though, the ACIA has made a splash.  One reason is the inevitable wrangling over policy recommendations.  News reports have suggested that the Bush administration has tried to suppress signs of support in the second, as yet unreleased, report, for the UN's Kyoto protocol or other mandatory policies for the control of greenhouse-gas emissions.  But even setting politics aside, this week's scientific report has still created a stir with its bold assessment of polar warming.  At first sight, its conclusions are not so surprising.  After all, scientists have long suspected that several factors lead to greater temperature swings at the poles than elsewhere on the planet.  One is albedo - the posh scientific name for how much sunlight is absorbed by a planet's surface, and how much is reflected.  Most of the polar regions are covered in snow and ice, which are much more reflective than soil or ocean.  If that snow melts, the exposure of dark earth (which absorbs heat) acts as a feedback loop that accelerates warming.  A second factor that makes the poles special is that the atmosphere is thinner there than at the equator, and so less energy is required to warm it up.  A third factor is that less solar energy is lost in evaporation at the frigid poles than in the steamy tropics.

And yet the language of this week's report is still eye-catching: "the Arctic is now experiencing some of the most rapid and severe climate change on earth."  The last authoritative assessment of the topic was done by the UN's Intergovernmental Panel on Climate Change (IPCC) in 2001.  That report made headlines by predicting a rise in sea level of between 10cm (4 inches) and 90cm, and a temperature rise of between 1.4°C and 5.8°C over this century.  However, its authors did not feel confident in predicting either rapid polar warming or the speedy demise of the Greenland ice sheet.  Pointing to evidence gathered since the IPCC report, this week's report suggests trouble lies ahead.

Hot on top

The ACIA reckons that in recent decades average temperatures have increased almost twice as fast in the Arctic as they have in the rest of the world.  Sceptics argue that there are places, such as the high latitudes of the Greenland ice sheet and some buoys at sea, where temperatures seem to have fallen.  On the other hand, there are also places, such as parts of Alaska, where they have risen far faster than average.  Robin Bell, a geophysicist at Columbia University who was not involved in the report's compilation, believes that such conflicting local trends point to the value of the international, interdisciplinary approach of this week's report.  As he observes, "climate change, like the weather, can be patchy and you can get fooled unless you look at the whole picture."

And there is other evidence of warming to bolster the ACIA's case.  For example, the report documents the widespread melting of glaciers and of sea ice, a trend already making life miserable for the polar bears and seals that depend on that ice.  It also notes a shortening of the snow season.  The most worrying finding, however, is evidence - still preliminary - that the Greenland ice sheet may be melting faster than previously thought.  That points to one reason the world should pay attention to this week's report.  Like a canary in a coal mine, the hyper-sensitive polar regions may well experience the full force of global warming before the rest of the planet does.  However, there is a second and bigger reason to pay attention.  An unexpectedly rapid warming of the Arctic could also lead directly to greater climate change elsewhere on the planet.

Arctic warming may influence the global climate in several ways.  One is that huge amounts of methane, a particularly potent greenhouse gas, are stored in the permafrost of the tundra.  Although a thaw would allow forests to invade the tundra, which would tend to ameliorate any global warming that is going on (since trees capture carbon dioxide, the greenhouse gas most talked about in the context of climate change), a melting of the permafrost might also lead to a lot of trapped methane being released into the atmosphere, more than offsetting the cooling effects of the new forests.

Another worry is that Arctic warming will influence ocean circulation in ways that are not fully understood.  One link in the chain is the salinity of sea water, which is decreasing in the north Atlantic thanks to an increase in glacial meltwaters.  Because fresh water and salt water have different densities, this "freshening" of the ocean could change circulation patterns.  The most celebrated risk is to the mid-Atlantic Conveyor Belt, a current which brings warm water from the tropics to north-western Europe, and which is responsible for that region's unusually mild winters.  Some of the ACIA's experts are fretting over evidence of reduced density and salinity in waters near the Arctic that could adversely affect this current.

The biggest popular worry, though, is that melting Arctic ice could lead to a dramatic rise in sea level.  Here, a few caveats are needed.  For a start, much of the ice in the Arctic is floating in the sea already.  Archimedes's principle shows that the melting of this ice will make no immediate difference to the sea's level, although it would change its albedo.  Second, if land ice, such as that covering Greenland, does melt in large quantities, the process will take centuries.  And third, although the experts are indeed worried that global warming might cause the oceans to rise, the main way they believe this will happen is by thermal expansion of the water itself.

Nevertheless, there is some cause for nervousness. As the ACIA researchers document, there are signs that the massive Greenland ice sheet might be melting more rapidly than was thought a few years ago.  Cracks in the sheet appear to be allowing melt water to trickle to its base, explains Michael Oppenheimer, a climatologist at Princeton University who was not one of the report's authors.  That water may act as a lubricant, speeding up the sheet's movement into the sea.  If the entire sheet melted, the sea might rise by 6-7 metres.  While acknowledging that disintegration this century is still an unlikely outcome, Dr Oppenheimer argues that the evidence of the past few years suggests it is more likely to happen over the next few centuries if the world does not reduce emissions of greenhouse gases.  He worries that an accelerating Arctic warming trend may yet push the ice melt beyond an "irreversible on/off switch".

Keeping a cool head

That is scary stuff, but some scientists remain unimpressed.  Patrick Michaels, a climatologist at the University of Virginia, complains about the ACIA's data selection, which he believes may have produced evidence of "spurious warming".  He also points out that even if Arctic temperatures are rising, that need not lead directly to the ice melting.  As he puts it, "Under global warming, Greenland's ice indeed might grow, especially if the warming occurs mostly in winter.  After all, warming the air 10º when the temperature is dozens of degrees below freezing is likely to increase snowfall, since warmer air is generally moister and precipitates more water."

Nils-Axel Morner, a Swedish climate expert based at Stockholm University, points out that observed rises in sea levels have not matched the IPCC's forecasts.  Since this week's report relies on many such IPCC assumptions, he concludes it must be wrong.  Others acknowledge that there is a warming trend in the Arctic, but insist that the cause is natural variability and not the burning of fossil fuels.  Such folk point to the extraordinarily volatile history of Arctic temperatures.  These varied, often suddenly, long before sport-utility vehicles were invented (see chart).  However, the chart also shows that the past few millennia have been a period of unusual stability in the Arctic.  It is just possible that the current period of warming could tip the delicate Arctic climate system out of balance, and so drag the rest of the planet with it.

Not everybody wants to hear a story like that.  But what people truly believe is happening can be seen in their actions better than in their words.  One of the report's most confident predictions is that the break-up of Arctic ice will open the region to long-distance shipping and, ironically, to drilling for oil and gas.  It is surely no coincidence, then, that the Danish government, which controls Greenland, has just declared its intention to claim the mineral rights under the North Pole.  It, at least, clearly believes that the Arctic ocean may soon be ice-free.

Source: economist.com 11 November 2004 from The Economist print edition photo source Science Photo Library

Arctic Takes the Heat

A University of Alabama scientist says global warming is not nearly as global as some people think.  With a global average temperature that was .54ºF warmer than seasonal norms, 2005 tied with 2002 as the second warmest year in the past 27, data processed at the university revealed.  Temperatures in 2005 followed a general pattern seen since 1978, with the most significant warming seen in the northernmost third of the planet.  Large regions of slightly warmer than normal temperatures covered much of the globe.  The Arctic atmosphere, however, has warmed more than 7 times faster than that over the southern 2/3s of the globe.  "It just doesn't look like global warming is very global," said John Christy, director of UAH's Earth System Science Centre.  "The CO2 from fossil fuels is distributed pretty evenly around the globe and not concentrated in the Arctic, so it doesn't look like we can blame greenhouse gases for the overwhelming bulk of the Northern Hemisphere warming over the past 27 years" he said.  "The most likely suspect for that is a natural climate change or cycle that we didn't expect or just don't understand."

Source: physorg.com 6 January 2006 © United Press International

Cold Water Flow from Arctic to Atlantic Is Falling, Study Finds

by Andrew C Revkin

Scientists have detected a substantial drop in the last 50 years in the flow of cold deep sea water leaving the Arctic and pouring into the Atlantic between Iceland and Scotland.  Climate experts say the obscure current, flowing south 2,000 feet beneath the surface, is one of the engines that drive the worldwide oceanic conveyer belt that also carries sun-warmed surface water north toward the pole.  Because the outflow of cold deep water has diminished, the influx of warm surface water that usually replaces it also has to have declined.  That decrease could explain a recent cooling of some coastal regions near the Norwegian Sea, said the authors of the study, which is described In today's issue of Nature.

The study was conducted by scientists in Norway, Scotland and the Faroe Islands, 400 miles east of Iceland, and centred on the flow of water over a submerged ridge east of those islands.  The changes there mesh with observations of major shifts in temperature, sea ice, currents and winds above the Arctic Circle and match some computer simulations of global warming.  But the scientists noted that the natural cycles in the area between the Arctic and the Atlantic remained poorly understood.  They said it was too soon to say climate change caused by human activity had changed the flow.

Other climate experts cautioned that it was premature to predict whether the change could have broader effects on Europe, because other influences besides sea temperature contribute to the generally mild conditions there.  "If I lived in the Faroes, I might be worried," said Or Richard Seager, a senior research scientist at the Lamont-Doherty Earth Observatory of Columbia University.  "But in Paris I wouldn't be worried."

Dr Knot Aagaard, an oceanographer at the Polar Research Centre of the University of Washington in Seattle said the research benefited from a focus on a remote, but vital junction in the ocean's circulatory system, the fairly narrow passages between Greenland and Europe that link Arctic waters with the North Atlantic.  Enormous amounts of water affected by conditions far to the north flow through the gaps, Dr Aagaard said, adding: "These constrictions give you a wonderful way to monitor what's going on over larger areas.  If you want to know changes in a big building, stand by the front door and you'll get a feel for it."

One author of the study had the benefit of living and working in the Faroes.  Dr Bogi Hansen, an oceanographer at the Faroese Fisheries Laboratory, said instruments that tracked currents, salinity and temperature were placed on the ridge east of the islands.  The water flowing over that sill, he said, constitutes a submarine river 10 miles wide and more than 600 feet deep, with a flow twice that of all the world's freshwater rivers combined.

Detailed readings from the anchored instruments over five years were matched up with separate measurements taken nearby since 1948 from weather ships, providing a much longer-term estimate of shifts in the deep currents.  The amount of cold deep water in that time, Dr Hansen said, has fallen 20% and is accelerating.  "If you look at the graph," he said, "you see the decrease is much faster in the last 5 years than it was over the 50-year period."  But Dr Hansen said the record was still not long enough to determine whether the change was linked to warming of the atmosphere from rising levels of greenhouse gases.

Source: The New York Times International section Thursday 21 June 2001


Will Global Warming Trigger a New Ice Age?

by Bill McGuire

If you can remember back to the bitter winters of the late 1970s and early 80s you might also recall that there was much discussion in scientific circles at the time about whether or not the freezing winter conditions were a portent of a new ice age.  Over the past couple of decades such warnings have been drowned out by the great global warming debate and by consideration of how society might cope in future with a sweltering planet rather than an icebound one.  Seemingly, the fact that we are still within an interglacial period, during which the ice has largely retreated to its polar fastnesses, has been forgotten - and replaced with the commonly-held view that one good thing you can say about global warming is that it will at least stave off the return of the glaciers.

Is this really true, or could the rapidly accelerating warming that we are experiencing actually hasten the onset of a new ice age?  A growing body of evidence suggests that, at least for the UK and western Europe, there is a serious risk of this happening - and soon.  The problem lies with the ocean current known as the Gulf Stream, which bathes the UK and north-west Europe in warm water carried northwards from the Caribbean.  It is the Gulf Stream, and associated currents, that allow strawberries to thrive along the Norwegian coast, while at comparable latitudes in Greenland glaciers wind their way right down to sea level.  The same currents permit palms to flourish in Cornwall and the Hebrides, whereas across the ocean in Labrador, even temperate vegetation struggles to survive.  Without the Gulf Stream, temperatures in the UK and north-west Europe would be 5°C or so cooler, with bitter winters at least as fierce as those of the so-called Little Ice Age in the 17th to 19th centuries.

The Gulf Stream is part of a more complex system of currents known by a number of different names, of which the rather cumbersome North Atlantic Meridional Overturning Circulation (Namoc) is probably the most apt.  This incorporates not only the Gulf Stream but also the cold return currents that convey water southwards again.  As it approaches the Arctic, the Gulf Stream loses heat and part of it heads back to warmer climes along the coast of Greenland and eastern Canada in the form of the cold, iceberg-laden current responsible for the loss of the Titanic.  Much, however, overturns - cooling and sinking beneath the Nordic seas between Norway and Greenland, before heading south again deep below the surface.

In the past, the slowing of the Gulf Stream has been intimately linked with dramatic regional cooling.  Just 10,000 years ago, during a climatic cold snap known as the Younger Dryas, the current was severely weakened, causing northern European temperatures to fall by as much as 10°.  Ten thousand years before that, at the height of the last ice age, when most of the UK was reduced to a frozen wasteland, the Gulf Stream had just 2/3 of the strength it has now.  What's worrying is that for some years now, global climate models have been predicting a future weakening of the Gulf Stream as a consequence of global warming.  Such models visualise the disruption of the Namoc, including the Gulf Stream, as a result of large-scale melting of Arctic ice and the consequent pouring of huge volumes of fresh water into the North Atlantic, in a century or two.  New data suggest, however, that we may not have to wait centuries, and in fact the whole process may be happening already.

So that the warm, saline surface waters of the Gulf Stream can continue to push northwards, there must be a comparable, deep return current of cold, dense water from the Nordic seas.  Disturbingly, this return current seems to have been slowing since the middle of the last century.  Bogi Hansen at the Faroese fisheries laboratory, and colleagues in Scotland and Norway, have been monitoring the deep outflow of cold water from the Nordic seas as it passes over the submarine Greenland-Scotland ridge that straddles the North Atlantic at this point.  Their results show that the outflow has fallen by 20% since 1950, which suggests a comparable reduced inflow from the Gulf Stream.  Although there is as yet no direct substantiation of this, and his colleagues point to reports of the cooling and freshening of the Norwegian Sea and to temperatures that are already falling in parts of the region as possible evidence of contemporary Gulf Stream weakening.

It also seems that it is not only the intensity of the outflow of cold water that is changing.  Bob Dickson of the Centre for Environment, Fisheries, and Aquaculture Science at Lowestoft, and colleagues, have reported a sustained and widespread freshening of returning deep waters south of the Greenland-Scotland ridge, which appears to have been going on for the past 3 or 4 decades.  Already the freshening is extending along the North American eastern seaboard towards the equator, in the so-called Deep Western Boundary current.

One of the scariest aspects of the current dramatic changes occurring in the system of North Atlantic currents is that the deep, southward-flowing limb of the Namoc can be thought of as representing the headwaters of the worldwide system of ocean currents known as the Global Thermohaline Circulation.  The possibility exists, therefore, that a disruption of the Atlantic currents might have implications far beyond a colder UK and north-west Europe, perhaps bringing dramatic climatic changes to the entire planet.  Yet again, this highlights the fact that global warming, for which we have only ourselves to thank, is nothing more nor less than a great planetary experiment, many of the outcomes of which we cannot predict.  Wallace Broecker, an ocean circulation researcher at New York's Lamont-Doherty Earth observatory, described the situation perfectly when he pointed out that "climate is an angry beast and we are poking at it with sticks."  Let's hope that when it truly turns on us, its teeth don't match its outrage.

Bill McGuire is Benfield Professor of Geophysical Hazards and director of the Benfield Hazard Research Centre at University College London.

Source: guardian.co.uk Thursday 13 November 2003 The Guardian

Source: USA Today Friday 22 June 2001 created by Nick Anderson

Uncertain Science?

Keep Off the Grass

by K Lloyd Billingslay

Sacramento, California - Quick!  Guess what is the biggest crop in the United States?  Wheat?  Corn?  Oats?  Marijuana?  Nice try.  Actually, it's lawn.

It's spring and many homeowners are out working on their lawn, which may soon bear the heavy bootprints of government.  Consider, for example, developments north of the border in Canada.  There, the Sierra Club, World Wildlife Fund, and dozens of local activist groups are pushing to ban the "cosmetic" use of pesticides on private property.  In other words, no use of weed killer on your own grass.  And the activists' motivation is not just personal.  They invoke a measure that came out of the 1992 Rio Declaration on the Environment and Development.  It's called the "Precautionary Principle," but it would be a mistake to regard it as a common-sense measure based on "better safe than sorry" - there's much more to it.  Under the precautionary principle, the lack of full scientific certainty is no reason for postponing action to protect the environment.  In other words, even if we don't have the facts, the government should take drastic measures as a first resort.  This approach carries risks of its own.

Power corrupts and public officials always need careful monitoring, not more power.  Further, public officials should pay more attention to science and less attention to discredited scaremongers.  Consider Stanford's Paul Ehrlich author of The Population Bomb (1968), a book that helped launch the modern environmental movement.  Ehrlich, a bug expert, predicted that, because of pesticides, life expectancy in the United States would drop to 42 by 1980, when the US population, he said, would be reduced to 22.6 million.  Needless to say, the mass starvation and depletion of resources he predicted also failed to take place.

Likewise, the Alar scare, pushed by such great scientists as Meryl Streep, needlessly terrified millions of people.  Likewise, electricity transmission and cellular phones do not, as some have charged, cause cancer.

No principle can alter the hard reality that the world is a risky place.  Living in proven earthquake zones such as Los Angeles and San Francisco, is risky.  Driving on the Santa Monica Freeway during rush hour is risky, as is riding a bicycle on city streets and eating in certain fast-food restaurants.  Lighting and heating our homes and disposing of wastes also entail risk.  In a world of limitations, actual risks must take priority over potential risk.

A chilling effect on technology is another likely consequence of the precautionary principle.  New technologies, including those that make for a cleaner environment, seldom appear overnight.  They require extended research and development.  But under the precautionary principle, they could be quashed if their first efforts do not achieve perfection.  The principle could also halt the building of new bridges and high-speed rail lines that would reduce pollution.

Perfection is not attainable in public life or anywhere else.  Therefore, sacrificing the good for the perfect, which the precautionary principle does, is no basis for public policy.  Responsible public policy rejects fear-mongering, realises the inevitability of tradeoffs, and carefully considers the best science before taking action.  That is why, at this point in history, policymakers need to reject the precautionary principle and consider instead a rule that usually applies to children: Keep Off the Grass.

The Pacific Research Institute promotes individual freedom and personal responsibility as the cornerstones of a civil society, best achieved through a free-market economy, limited government, and private initiative.  PRI researches and analyses critical issues facing California and the nation, and crafts strategies for policy reform

Source: Pacific Research Institute © United Press International

See also:

bulletWorld's End (the next page in this section) - Even if temperatures rise only moderately, some scientists fear the climate would reach a "tipping point" - a point at which even a tiny additional increase would throw the system into violent change...
bulletFronting Up to Rising Seas (two pages further in this section) - So far the sea has completely engulfed only uninhabited, relatively small islands.  But all around the shores of the world's atolls - often described as idylls - the crisis is growing...
bulletPoseidon Adventure - (three pages further in this section) - Not everyone agrees on the speed with which global warming is causing the oceans to rise: "...the current sea level rate of rise after cycle 276 is 0.9 mm/yr, half the rate claimed for the last 100 years, and less than 1/5 the rate claimed for the 21st century..."

For pages on several other types of natural disasters - including lightning strikes, tornados, hurricanes, volcanoes, floods, and more - as well as some great satellite and tree photos, clicking the "Up" button immediately below takes you to the Table of Contents page for this Environment section.

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