Les Knight

Advancing technology wasn't considered much in Malthus' argument. Population, he said, would increase until stopped by natural forces such as hunger and disease. Although he didn't foresee the advances which have allowed us to grow to 6.7 billion, he seems to be right that we will increase until stopped by natural forces. Lower birth rates in affluent regions may be exceptions, though crowding is a natural force. And comparing national averages further confuses things. When a couple's perception of future income improves, they tend to reproduce more, as new immigrants demonstrate. Improving living standards is worthwhile, but it's not a method of improving birth rates, no matter how much we might want it to be true. Comparing advances in the first half of the 20th century with the second half show this to be true in my opinion. This relative stagnation may be enhanced by entrenched economic interests which resist change. The Green Revolution comes up against the limits of mechanization and fossil fuels, but our numbers continue to grow due to momentum -- an additional 50% before leveling off is the current extrapolation. As awful as this Malthusian situation may become, it won't cause our extinction.

Discover magazine made a list in 2000 of 20 ways the world, Homo sapiens, could end. http://www.ldolphin.org/twentyways.html Although we may have already disrupted the food chain to the tipping point, it's worth trying to slow, stop, and reverse our direction. Unfortunately, this isn't likely to happen because of the massive efforts required. For example, the gyre of plastic in the north Pacific, twice the size of Texas, breaks into smaller and smaller pieces, which enter aquatic life forms. How this will affect the food chain is unknown, but it's occurring at the base of the chain with implications all the way up. To figure the odds of our extinction, I look at the probability we will cause a collapse of the biosphere if we continue as we are: 90%. Then I look at the probability we will make global efforts required to avoid this collapse: 10%. My estimates were pulled out of the air, so yours will have at least equal validity. A collapse of global civilization before we succeed in causing a collapse of Earth's biosphere would serve to preserve our kind. If 99.99% of us were wiped out, enough of us would still be around to keep our species going. In the long run, this would again endanger the rest of Earth's biosphere. Our extinction would benefit all other life forms on Earth, as shown in the thought experiment by Alan Weisman, _The World Without Us_.