“A mature leafy tree produces as much oxygen in a season as 10 people inhale in a year.” “A 100-foot tree, 18 inches diameter at its base, produces 6,000 pounds of oxygen.” “On average, one tree produces nearly 260 pounds of oxygen each year. Two mature trees can provide enough oxygen for a family of four.” Nov 19, 2019 Thoughtco.com
A tree uses carbon dioxide to grow. A living tree draws in and stores twice as much carbon dioxide than a fallen tree releases. But when the tree is cut down, it releases its stored carbon dioxide. For example, dead Amazonian trees emit an estimated 1.9 billion tons (1.7 billion metric tons) of carbon dioxide into the atmosphere each year, according to a study published in the journal Nature Communications in 2014. The same trees typically absorb about 2.2 billion tons (2 billion metric tons) of carbon dioxide. Carbon dioxide makes up around 82.2 percent of all U.S. greenhouse gas, according to the Environmental Protection Agency
Out of the 6 million square miles (15 million square kilometers) of tropical rainforest that once existed worldwide, only 2.4 million square miles (6 million square km) remain, and only 50 percent, or 75 million square acres (30 million hectares), of temperate rainforests still exists, according to The Nature Conservancy. Ranching, mining, logging and agriculture are the main reasons for forest loss. Between 2000 and 2012, more than 720,000 square miles (2 million square km) of forests around the world were cut down — an area about the size of all the states east of the Mississippi River. Life Science March 20. 2014