As climate change and its many impacts unfold, many worse than we had forecasted or feared, many observers have indicated that Earth is entering a “new normal.” This is not wrong. However, with respect to our ability to understand, adapt to, and predict environmental change from here on out, it is probably more accurate to say there is no normal. The climate and environment that we will contend with will be unlike any our species—much less our infrastructures, institutions, and cultures—has ever encountered. I agree with those who say, sometimes circumspectly and sometimes directly, that it is time to panic. Not in the sense of panic as uncontrollable fear or anxiety that can cause wildly unthinking behavior, but in the sense of another definition: a frenzied hurry to do something. Scientists hate to be called alarmist, but when the house is on fire, you sound the alarm.

New York Times, February, 2019

Every day, it seems, there is another news story or reports of yet more evidence that the global climate is changing, either as we have predicted for years—or worse and faster. The climate system is incredibly complex, and climatologists, climate modelers and paleoclimatologists are furiously working to reduce the uncertainty. Despite the uncertainties and complexities, at this point it is clear that:

•Global mean temperatures are rising.

•Ocean heat content is increasing.

•Sea ice cover is, on average, decreasing (both in areal extent and thickness).

Arctic sea ice cover is in serious long-term decline (photo: Huffpost Canada)

•Ice sheets and glaciers are shrinking.

•Permafrost is thawing.

•Sea level is rising. 

•Changes in climate-sensitive biota, ecosystems, and landforms are all consistent with a warming climate. 

•The major driving force is a dramatic increase in heat-trapping greenhouse gases such as carbon dioxide and methane.