If a Tree Falls in the Forest, and No One Is Around to Hear It, Does Climate Change? (2 of 2) (image) National Science Foundation Share Print E-Mail Caption There are roughly 42 million square kilometers of forest on Earth, a swath that covers almost a third of the land surface, and those wooded environments play a key role in both mitigating and enhancing global warming. Credit Nicolle Rager Fuller, National Science Foundation Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.