To the editor:

It’s difficult to be precise within the 250-word limit in a letter to the editor. The point of my previous letter (Public Forum, Jan. 26) was about human impact on climate, but my reference to the ancient Roman and Mayan civilizations appears to have confused the issue.

I simply meant to point out one of many accepted reasons that led to their mutual cultural decline; that being a burgeoning population, not to imply the only reason.

So I’ll keep it closer to this century and keep it simple. We breed like rabbits. Our cities get bigger. We use and waste more water. We cut down more trees, build more cars and generally treat our local and global environment like a landfill.

There is a natural cycle of global warming and cooling; that is not in doubt. But to say that humans can’t affect climate change is arrogant. The Dust Bowl in the ’30s is a perfect example. Years of sustained drought (natural cycle) was exacerbated by the misuse of land through decades of extensive farming (human impact).

Poor plowing techniques killed most of the natural prairie grasses that kept the topsoil in place and retained moisture during drought. So without the grasses’ natural anchors to keep the soil in place, it dried out, turned to dust and blew away. This rendered around 100 million acres of land useless and affected weather patterns for years.

Natural climate shifts are, well, natural, but humans have had and continue to have a hand in making things worse.