I grew up in a place in Michigan that 14,000 years ago was under an icecap. For this reason, I do not think that climate change is unnatural. Nor do I think that it is "bad". It may have good or bad consequences for you, depending on what the change is, and where you are. Climate change is inevitable -- man has lived with it for a long time -- and it is foolish to think that man can maintain the climate in a state that prevailed at one fleeting interval of time. So let's just stop whining about it.
I look forward to seeing Al Gore's documentary on global warming, though it might be more convincing if it did not come from a man who went through his entire college career without taking a single class in mathematics or the physical sciences. As an alternative view I commend the following article from the Scientific American:How Did Humans First Alter Global Climate?
; Scientific American Magazine
; March 2005; by William F. Ruddiman http://www.sciamdigital.com/index.cfm?fa=Products.ViewIssuePreview&ARTICLEID_CHAR=F9374686-2B35-221B-635B1D2A02A8B6D5
"The scientific consensus that human actions first began to have a warming effect on the earth's climate within the past century has become part of the public perception as well. With the advent of coal-burning factories and power plants, industrial societies began releasing carbon dioxide (CO2) and other greenhouse gases into the air. Later, motor vehicles added to such emissions. In this scenario, those of us who have lived during the industrial era are responsible not only for the gas buildup in the atmosphere but also for at least part of the accompanying global warming trend. Now, though, it seems our ancient agrarian ancestors may have begun adding these gases to the atmosphere many millennia ago, thereby altering the earth's climate long before anyone thought.
"New evidence suggests that concentrations of CO2 started rising about 8,000 years ago, even though natural trends indicate they should have been dropping. Some 3,000 years later the same thing happened to methane, another heat-trapping gas. The consequences of these surprising rises have been profound. Without them, current temperatures in northern parts of North America and Europe would be cooler by three to four degrees Celsius--enough to make agriculture difficult. In addition, an incipient ice age--marked by the appearance of small ice caps--would probably have begun several thousand years ago in parts of northeastern Canada. Instead the earth's climate has remained relatively warm and stable in recent millennia."