Rainforest (IMAGE) Princeton University Caption A study led by Princeton University researchers suggests that hotter nights may wield more influence than previously thought over the planet's atmosphere as global temperatures rise -- and could eventually lead to more carbon flooding the atmosphere. The researchers determined that warm nighttime temperatures, specifically in the tropics, lead plants to release more carbon through a process known as respiration. Average nighttime temperatures in tropical regions such as Manaus, Brazil, (above) have risen by 0.6 degrees Celsius since 1959. Further temperature increases risk turning Earth's land-based carbon-storage capacity, or sink, into a carbon source. Credit William Anderegg, Princeton Environmental Institute. Usage Restrictions None License Licensed content 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.