Planting trees in urban areas can help mitigate carbon dioxide levels because trees can sequester carbon and offset some energy use for cooling, as some studies have illustrated in California.
The California Global Warming Solutions Act of 2006 (AB32) requires a reduction in greenhouse gas emissions to 1990 levels by 2020. This amounts to a reduction of 173 million metric tons from the level projected for 2020.
Aerial photography revealed 242 million potential sites for planting individual trees …