Trees have difficulty sequestering carbon dioxide (CO2), a greenhouse gas, in warmer, drier climates, meaning they may no longer be the answer to offsetting humanity's carbon footprint as the planet continues to warm, according to a new study. by Penn State researchers. "We found that trees in warmer, drier climates are essentially coughing instead of breathing," said Max Lloyd, assistant professor of geoscience research at Penn State and lead author of the study, which was recently published in the journal Proceedings of the National Academy of Sciences. “They send CO2 directly back into the atmosphere much more than trees in cooler, wetter conditions.” (LUIGI BARBIERI, more at meteogiornale.it)