Hi Alex,

I think the "fact" that humans are starting to cause the earth to warm is yet to be proven. As a matter of fact, it appears the eart has been cooling, not warming. I'm an avid sportsman. I love to hunt, fish, hike,etc. That requires that I be interested in preserving the streams, forests, etc, because without them, I couldn't enjoy my leisure time. I want to do whatever it takes to make sure we have a clean earth, but I don't want to have scientists, who are only making a money grab, tell me that I am the cause, while they furnish no proof. They not only don't furnish proof that I'm the cause of the problem, they don't furnish proof that there is a problem.

>Hi John,
>
>We all know from simple observation that many things oscillate, including the weather. There is very interesting book that won the 2002 Phi Beta Kappa Science Book Award called "A Brain for all Seasons". It has the following quote:
>
>"One of the most shocking realizations of all time has slowly been dawning on us: the earth's climate does great flip-flops every few thousand years, and with breathtaking speed. In just a few years, the climate suddenly cools worldwide. With only half the rainfall, severe dust storms whirl across vast areas. Lightning strikes ignite giant forest fires. For most mammals, including our ancestors, populations crash."
>
>While the point of the book is the effect of those climate flip flops on brain evolution, the book does a good job of explaining what drives the flip flops, from the precession of the earth to rapid sea current changes. Man made changes are only a recent addition to the causes.
>
>Something nice about this book is that the author published the entire text on the internet!
>
>http://williamcalvin.com/BrainForAllSeasons/
>
>Alex
>