In a biological shocker, scientists have discovered that all sorts of trees, from a Texas red oak to a birch in Michigan, all keep their leaves
at the same temperature — about 71F/21C. No matter the ambient temperature around the leaves.
Beyond the wow factor, scientists say this may have implication for how tree rings have been used, and are used, to analyze weather and climate from the past. Here’s why:
For decades, scientists studying the impact of global warming have measured the oxygen isotope ratio in tree-rings to determine the air temperature and relative humidity of historical climates.
Oxygen atoms within water molecules evaporate more or less quickly depending on the number of neutrons they carry, and the ratio between these differently weighted atoms in tree trunk rings has been used as a measure of year-to-year fluctuations in temperatures and rainfall.
“The assumption in all of these studies was that tree leaf temperatures were equal to ambient temperatures,” lead researcher Brent Helliker told AFP. “It turns out that they are not.”
Read the full story for more details; especially to prepare yourself for the James Imhofes of the world who will likely use this to argue against the reality of anthropogenic glocal warming.
On the more serious side, researchers did not indicate how much this might force past paleoclimate measurements to be recalibrated or in what ways.
