Not so true – think about it. If 1 trillion palm oil trees were planted, new diseases would develop to deal with the imbalance. If current industrialized areas were simply allowed to return to nature that would enable 1 trillion trees to plant themselves, it would help. Man deciding to plant trees liked by humans will more than likely make things worse. Forests depend on natural diversity, not man-made interventions. Planting a massive number of trees is the most effective way to combat global warming, scientists have said. Reforesting an area the size of the United States could capture two-thirds of manmade carbon emissions.