Trucks here burn diesel fuel contaminated with more than 130 times the pollution-causing sulfur that the United States allows in most diesel. While car sales in China are now growing even faster than truck sales, trucks are by far the largest source of street-level pollution.

Tiny particles of sulfur-laden soot penetrate deep into residents’ lungs, interfering with the absorption of oxygen. Nitrogen oxides from truck exhaust, which build all night because cities limit truck traffic by day, bind each morning with gasoline fumes from China’s growing car fleet to form dense smog that inflames lungs and can cause severe coughing and asthma.

Instead of tilting at the windmills of CO2 and cow farts, they should be going after real dangers like SO2, NO2, heavy metals, and other real pollution. Most of those probliems are in the 3rd World though.

Guess the environmentalists in 1st World countries are a lot like lawyers. Their numbers have increased beyond their need and they don't have enough real causes to supply them with honest work, so they create issues like class action lawsuits and green house gas emissions to keep them employed.