Tuesday, March 23, 2004
WALTER CRONKITE ON GLOBAL WARMING
"The contempt of the Bush administration for environmentalists and their concerns is well known by now. While evidence of man- made environmental damage mounts, the Bush team 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 environmental issues - global warming.
First, the administration claimed that global warming was the work of liberal hysterics and had been discounted by "more sober scientists." Then, it admitted that it was happening but said there was no proof humans caused it, or could fix 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."
"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 as gay marriage or the 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."