Enlarge / We have pretty clear evidence that declining ozone levels were something more than liberal scare tactics. (credit: NASA )

Conservative political commentator Matt Walsh took to Twitter last Wednesday to say that the widely held belief that humans are causing climate change is, in fact, a crock. The podcaster and Daily Wire columnist apparently knows this because previous environmental issues we were concerned about in the past—namely acid rain and holes in the ozone layer—disappeared, never to be heard about again.

“Remember when they spent years telling us to panic over the hole in the ozone layer and then suddenly just stopped talking about it and nobody ever mentioned the ozone layer again?” Walsh tweeted . “This was also back during the time when they scared school children into believing that "acid rain" was a real and urgent threat,” Walsh tweeted again .

It’s true that you don’t hear much about acid rain anymore, and discussions about humanity’s long-standing propensity to metaphorically kick the planet in the groin have largely moved away from the ozone layer to newer, flashier issues like sea level rise, rising global temperatures, and mass species die-offs served with a side of ecosystem collapse . (Although, if you know where to look , you can still find mention of the ozone hole.)