Study: Minnesota, Wisconsin could plant millions of acres of trees to soak up carbon dioxide A Nature Conservancy report finds pasture land and open urban areas offer huge potential to capture carbon dioxide and slow climate change, and UMD efforts are helping provide more trees to plant. 7:57 am, Feb. 10, 2021 × A volunteer plants a tree along Duluth's Park Point. A Nature Conservancy study finds that millions of acres of trees could be planted across the U.S. to soak up millions of tons of the carbon dioxide that causes climate change. (Clint Austin / 2008 file / News Tribune) An all-out effort to reforest land across the United States could plant trees on another 133 million acres to help soak up carbon dioxide and limit global climate change.