>But are we any better at surviving the consequences of these changes than our ancestors. When the natural cycle brings round another Ice Age we could probably survive slightly better than our ancestors but we could do nothing to stop it.

I disagree Don. I think we can actually prevent the next ice advance.

65 million years ago the earth had existed for several hundred million years without an ice age. The biosphere was rich in vegetation and animal life. Then the asteroid hit, all the carbonaceous matter was covered in dust but unable to decompose due to the sterile atmosphere and land. This carbon matter pooled up and became sequestered as petrocarbons.

Had humans not come along, it would have taken a total of about 200 million years for the tectonic plates to recycle, thus burning the carbon matter and ejecting it through volcanoes as carbon dioxide. But humans have come along. We have been pumping the petrocarbons back into the biosphere at a very high rate. If we try real hard, we can get most of the carbon back into the carbon cycle, thus raising the temperature of the earth back to its normal state and providing enough carbon for bountiful plant and animal life.

Man can change things and in a very positive way. We can save 135 billion years of slowly returning the sequestered carbon back into the biosphere through continental drift.

With any luck, we can increase the temperature of the upper troposphere sufficiently to prevent liquid nitrogen from forming during an extreme flooding event that will eventually come, just as it did in Noah's day. In fact, we could also reduce some of the future flooding by increasing atmospheric temperatures.

Don't give up. There's a lot humans can do to stop the next ice advance.

Dave