Many people are becoming aware of global warming simply because of recent warm weather, plus increasing hurricane activity.

Clearly the Earth's climate is changing - here are the facts:

• Average global temperatures have risen about 0.5 °C in the past century
• Glaciers have melted and retreated dramatically
• Ecosystems around the world are being altered

Here are some of the dire warnings :

• The world has already entered a state of dangerous climate change. If the current pace of change continues a catastrophic sea level rise of 13 feet could occur in this century.
• Recent studies suggest that climate change is rapidly leading to genetic impacts. Tiny shifts in average temperature are effecting genetic changes in living organisms.
• Increases in hurricane intensity are due to humanity's greenhouse gas emissions. Scientists calculate that two-thirds of the recent rise in sea temperatures is due to human emissions.
• Siberia is melting. Vast tracts of Russian tundra, frozen for tens of thousands of years, are starting to thaw. Some experts say the process is taking place so fast, they can only attribute it to the effects of global warming.
• The amount of Arctic sea ice is shrinking not only in the summer but in the winter as well - linked directly to global warming. In 2005 & 2006, the extent of winter ice was about 6% smaller than the average amount over the past 26 years. This is much faster than the previously observed long-term decrease of 1.5% to 2% per decade.

But, this is not new news. These changes started 18,000 years ago as the earth emerged from the Ice Age. Glaciers have alternately retreated and advanced as Earth has warmed and cooled, in cycles spanning hundreds, thousands, and millions of years.

Historical data from ocean sediments and ice cores indicate that warm interglacial periods of 15,000 - 20,000 years separate each major ice age. We currently are in an interglacial period, and are due (some say overdue) for the next 100,000-year Ice Age.

There are many sources for the million-year history of the variations of temperature. Perhaps our human ego makes us think that we are the primary cause, and that we can control nature and stop the changes. Over the past centuries, data indicates that the Earth is indeed warming, but most of the warming (about 95%) is due to natural causes and beyond our control.

Global warming should be expected to continue, perhaps as high as medieval times. Then, there will be a sharp drop, to a small "ice age", which will take about another 600 years. Perhaps at that time, human-generated global warming may even have a positive effect. (smile)

Because of the sound-bytes and short-attention span of trigger-happy media, we are completely unprepared for long-term issues. The media tests out several scary issues, seeing which will generate widespread "traction". And then we run scared. We start making laws to prepare for the "cataclysmic changes" that are coming.

Global-warming is a long-term issue. Let's recognize that human effects are the cause of only about 5% - the other 95% is "natural".

I agree with Al Gore that we should "manage" the human effects on global warming through reduced emissions and other solutions he suggests. But, let's not spend our national budget trying to stop or reverse a natural process.