It can be challenging for modeling to distinguish significant changes from what may be normal variations in climate over time. A recent paper published in Scientific Reports shares observational evidence that we have already seen changes to temperature extremes over large parts of the Earth, and that human impacts have been underestimated by climate models. The authors also argue that changes happened earlier (as early as the 1960s by some estimates) than previously predicted. They go on to say that future changes may also happen sooner than current climate models predict.
Observed changes have supported what would be expected from an overall warming trend—more hot and fewer cold days and nights. There are some exceptions to this trend, such as areas in the southeast/central U.S.; however, these regions are expected to show similar warming trends with continued greenhouse gas emissions. Read “Widespread persistent changes to temperature extremes occurred earlier than predicted” in full to learn more.