BY WALTER CRONKITE

The contempt of the Bush administration for environmentalists and their concerns certainly is well enough known by now. While the evidence of man-made environmental damage continues to mount, the Bush team stubbornly resists its implications like a defeated army whose rear guard fights off its pursuers as it retreats. That has been especially true of its handling of the most serious of all the environmental issues – global warming.

At first, the administration simply claimed that it wasn't proven, that it was the work of liberal hysterics and had been discounted by what the administration called more sober scientists. Its next begrudging retreat was the acknowledgement that it was happening but that there was no proof that human activity – such as polluting smokestacks and exhaust pipes – had anything to do with it, and therefore there was nothing we could do about it.

Retreat No. 3 was the White House discovery that, yes, indeed, some of the warming was due to human activity, and we should take steps, say, to reduce emissions, but those steps should be voluntary on the part of industry.

There are two scientific theories that have been gaining credence in recent years that challenge the sanity of that kind of resistance to fact – and make no mistake about it, global warming is a fact.

Both theories begin with a phenomenon that is taking place right now. Scientists are beginning to understand climate as a complex interactive system that is affected by everything from the emission of greenhouse gases, to deforestation, to the condition of Arctic and Antarctic glaciers.

It is a system with a feedback mechanism. For example, higher temperatures lead to the melting of sea ice, which exposes more water to the sun. The water absorbs more solar energy, which accelerates global warming, and so on. Scientists fear that such feedbacks might produce a self-sustaining and accelerating warming that is beyond human control.

The second theory goes by the name of Abrupt Climate Change. It suggests that catastrophic results of global warming might not occur gradually, as most have expected, but quite suddenly – within a few years. This theory also starts with the melting of glaciers and sea ice, but involves the dilution of seawater's salinity – or salt content – that results. That salt content is a key element in an ocean current that takes heat from the tropics northward and cold water southward and in the process moderates temperatures in the Eastern United States and much of Europe.

The collapse of this so-called conveyor could, in the worst case, produce a new ice age. The best case would give us severe winters, increasingly violent storms, flooding, drought and high winds around the globe, disrupting food production and energy supplies and raising sea levels high enough to flood coastal cities and make them unlivable.

These are not predictions but real possibilities – far more possible today than scientists had previously believed. And while the politicos in the White House continue to stick their heads in the sand, some people at the Pentagon have been taking the issue very seriously. Two scientists (one of them a Pentagon official) took on the task of studying the national-security implications of Abrupt Climate Change.

What they came up with was a world whose "carrying capacity" – the number of people the globe can sustain – is being progressively lowered, a world where war becomes the rule, not the exception, and where wars are no longer fought for ideological, religious, or geopolitical reasons – but for resources and survival. This unclassified Pentagon study, completed last fall, has been released to several news organizations and was highlighted in the Feb. 9 edition of Fortune magazine.

One thing we have to keep in mind: While these might only be worst-case scenarios, many of the conditions and processes scientists think might trigger them already are present or under way. Global warming is at least as important an issue as gay marriage or the rising cost of Social Security. And if it is not seriously debated in the general election, it will measure the irresponsibility of the entire political class. This is an issue that cannot, and must not, be ignored any longer.

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Write to Walter Cronkite c/o King Features Syndicate, 888 Seventh Ave., New York, NY 10019, or e-mail him at mail@cronkitecolumn.com.

(c) 2004 Walter Cronkite

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