Sizzling year. Torrid decade. Blistering future?

5 FEB 1999 When the global warming debate first heated up in the late 1980s, scientists warned that the Earth our grandkids walked might be cooking like a fried egg on an El Paso sidewalk. The prediction ran like this: Gathering levels of greenhouse gases in the atmosphere would trap heat, causing a rapid warming and damaging the atmosphere, the oceans and the economy.

Measurements at weather stations around the globe show these global average temperatures in degrees Celsius, relative to the 1951-1980 average (about 14°C). Recent data is better than older data. Goddard Institute for Space Studies.

And our grandchildren could face drought, fire and flood -- essentially a list of biblical catastrophes. These days, after 18 straight months of record temperatures, the concern is not about the next generation. It's about next year. And 18 record-setting months are only one of the warning signs.

	1998 saw the 20th straight year of above-normal surface temperatures, 0.4 degrees F hotter than 1995, the previous record.
	In 1998, the hottest year since scientists began keeping track of such things in the mid-1800s, global temperatures were 1.04 degrees F above the average for 1961-1990.
	The 10 warmest years in the 150-year history of recorded temperatures have all occurred since 1983.
	In Alaska and other polar regions, the permafrost is melting and whole forests are dying due to an increase of insects associated with the warming.

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Now that El Niño has dissipated, 1999 could be cooler than hyper-hot 1998. Will that be the start of a downward trend, or will the warming resume? Will the future bring more disasters like Hurricane Mitch, the murderous storm that devastated Central America? (More frequent and more furious storms, after all, are a predicted consequence of warming.) Will the future bring more deadly heat waves like the one that killed thousands in India in 1998? Will it see more catastrophic fires like those that scorched Indonesia and Amazonia last summer?

There is no proof we're on the verge of dangerous -- let alone catastrophic -- warming. Climate varies, after all, just like weather. The American Geophysical Union, a group of earth scientists, warned last week that warming is a predictable consequence of putting so much carbon dioxide into the atmosphere. "There is no known geologic precedent for the transfer of carbon from the Earth's crust to atmospheric carbon dioxide, in quantities comparable to the burning of fossil fuels, without simultaneous changes in other parts of the carbon cycle and climate system."

One cause of worry is recent evidence that climate is less stable than once assumed. A few thousand years ago, the average temperature apparently soared by 9 to 11 degrees Fahrenheit in just five years -- at least in Greenland.

That's what we call mighty flighty
As The Why Files digs out from yet another snowstorm, the idea of selling snow shovels and swapping skis for swim suits sounds soothing. But global warming, caused by an increasing concentration of carbon dioxide, is a distinctly discomforting thought, since it's likely to bring rising sea levels, droughts and fires that disturb agriculture, economies and ecosystems alike.

Is the ongoing heat wave the long-sought "signal" of global warming? And what's this business about abrupt changes in past climates? So slip on your shades, slap on some sun screen, and scurry along on an electronic expedition to the heart of the warming debate.

http://whyfiles.org/080global_warm/index.html