Unsettled: What Climate Science Tells Us, What It Doesn’t, and Why It Matters

by Steven E. Koonin

The failure of even the latest models to warm rapidly enough in the early twentieth century suggests that it’s possible, even likely, that internal variability—the natural ebbs and flows of the climate system—has contributed significantly to the warming of recent decades.20 That the models can’t reproduce the past is a big red flag—it erodes confidence in their projections of future climates. In particular, it greatly complicates sorting out the relative roles of natural variability and human influences in the warming that has occurred since 1980.

Science stories are almost always stories of nuance; they require time and research.

Omitting numbers is also a red flag. Hearing that “sea level is rising” sounds alarming, but much less so when you’re told it’s been going up at less than 30 cm (one foot) per century for the past 150 years. When numbers are included, omission of uncertainty estimates is another thing to watch out for in non-expert discussions of climate science,