Scott Paul’s letter “Think of Carbon Law’s World Impact" (4/1/09) confuses two related but distinct issues: air pollution and climate change. He states that, “Air pollution causes 750,000 premature deaths in China, while 25% of the particulate matter over Los Angeles originates in China, which has become the world's largest carbon emitter.” Some particulate matter (soot and ash from burning coal, for example) contains carbon, but a carbon footprint is a measure of greenhouse gas emissions, specifically carbon dioxide, not of solid particles. CO2 is essential for plant life and non-toxic to humans, and has not caused a single premature death. If breathing carbon dioxide causes cancer, we’re all doomed.
The only danger presented by CO2, which led to the Supreme Court decision—mistaken in my opinion—to classify it as an air pollutant, are future dangers, the potential to harm future generations by its unproven contribution to rising global temperature. Spending money to reduce particulate air pollution makes sense, but obsessing over a harmless ubiquitous form of carbon in CO2 is, in the memorable phrase of the Journal editors, a form of climate neurosis.