You’ve probably heard about the famous Simon-Ehrlich wager, but did you know the Ehrlich asked for a rematch? Paul Ehrlich and Steve Schneider proposed to bet $1000 on each on the following:

1. The three years 2002-2004 will on average be warmer than 1992-1994. (Rapid climate change associated with global warming could pose a major threat of increasing droughts and floods.)

2. There will be more carbon dioxide in the atmosphere in 2004 than in 1994. (Carbon dioxide is the most important greenhouse gas driving global warming.)

3. There will be more nitrous oxide in the atmosphere in 2004 than in 1994. (Nitrous oxide is another greenhouse gas that is increasing due to human disruption of the nitrogen cycle.)

4. The concentration of ozone in the lower atmosphere (the troposphere) will be greater in 2004 than in 1994. (Tropospheric ozone is a component of smog that has important deleterious effects on human health and crop production.)

5. Emissions of the air pollutant sulfur dioxide in Asia will be significantly greater in 2004 than in 1994. (Sulfur dioxide in the atmosphere becomes sulfuric acid, the principal component of acid rain, and it is associated with direct damage to human health, forests, and crops.)

6. There will be less fertile cropland per person in 2004 than in 1994. (Much of Earth’s best farmland is being paved over, but even if it weren’t, population growth will reduce per-capita acreage.)

7. There will be less agricultural soil per person in 2004 than in 1994. (Erosion virtually everywhere far exceeds rates of soil generation.)

8. There will be on average less rice and wheat grown per person in 2002-2004 than in 1992-1994. (Rice and wheat are the two most important crops consumed by people.)

9. In developing nations there will be less firewood available per person in 2004 than in 1994. (More than a billion people today depend on fuelwood to meet their energy needs.)

10. The remaining area of virgin tropical moist forests will be significantly smaller in 2004 than in 1994. (Those forests are the repositories of some of humanity’s most precious living resources, including the basis for many modern pharmaceuticals worldwide.)

11. The oceanic fisheries harvest per person will continue its downward trend and thus in 2004 will be smaller than in 1994. (Overfishing, ocean pollution, and coastal wetlands destruction will continue to take their toll.)

12. There will be fewer plant and animal species still extant in 2004 than in 1994. (Other organisms are the working parts of humanity’s life support systems.)

13. More people will die of AIDS in 2004 than did in 1994 (as the disease takes its toll of already infected individuals, continues to spread in Africa, and takes off in Asia.)

14. Between 1994 and 2004, sperm counts of human males will continue to decline and reproductive disorders will continue to increase. (Over the past fifty years, sperm counts worldwide may have declined as much as 40 percent. Paul and Steve bet this trend will continue due to the widespread use and environmental persistence of hormone-disrupting synthetic organic chemical compounds.)

15. The gap in wealth between the richest 10 percent of humanity and the poorest 10 percent will be greater in 2004 than in 1994.

Simon objected, quite properly in my view, that many of these bets have little or nothing to do with human welfare. (E.g., why is #15 about inequality instead of the per-capita income of the poorest 10%?! Why is #6 about cropland instead of food production? Why is #8 about rice and wheat instead of calories?)

The parentheticals try to make this connection, of course, but by my lights, few of them succeed. Still, some of these 15 bets seem a lot closer to human welfare than others. So: Which of these 15 bets should Simon have been willing to take?