In a new Wall Street Journal piece (Climate Science Is Not Settled, September 19) former BP scientist and DOE Undersecretary of Science Steven Koonin delivers a paradoxical case for climate change inaction. Thus, contrary to Koonin’s assertion that past climate change suggests a policy of caution, a more appropriate conclusion would be that insights gained from past climate change should be leading to much more aggressive policy action than is now underway. That climate change can cause sea level to change is a key lesson from past changes in the climate that Koonin fails to mention.