There will be more carbon dioxide in the atmosphere in 2004 than in 1994. Carbon dioxide is the most important gas driving global warming. There will be more nitrous oxide in the atmosphere in 2004 than in 1994. Nitrous oxide is another greenhouse gas that is increasing because of human disruption of the nitrogen cycle. The concentration of tropospheric ozone globally will be greater in 2004 than in 1994.
Tropospheric ozone has important deleterious effects on human health and crop production.
Emissions of sulfur dioxide in Asia will be significantly greater in 2004 than in 1994. Sulfur dioxide becomes sulphuric acid in the atmosphere, the principal component of acid rain, and it is associated with direct damage to human health. There will be less fetile cropland per person in 2004 than in 1994. As the population grows, some of Earth's best farmland is being paved over. There will be less agricultural soil per person in 2004 than there was in 1994.