A geoscientist recently wrote in about the current warming trend. He rejects the near-unanimous consensus of climate scientists that global warming is manmade, even though climate science is not his specialty.

He says the earth warms and cools in “statistical up and down swings” and glowingly describes Arizona in the Triassic age as a warm, lush, inviting place. He fails to mention that 250 million years ago humans weren’t around to see if they could have survived the Triassic or the preceding Permian age. Both had excessive C02 levels resulting in heat levels that killed 76 percent and 96 percent of all life, respectively.

He also breezily highlights a 100-year drought that drove the Salado people from the Tonto Basin in the 1400s. He seems to be saying “Calm down, folks. It’s just a statistically routine climate-caused exodus; happens all the time!”

It is not a reassuring or soothing example because today’s serially record-breaking heat and receding water levels (Lake Mead at 36 percent capacity) may over the next 50-100 years cause a similar exodus. However, today’s “tribe” (read: multiple states) will have tens of millions fleeing. These conditions will not be nicely contained in the Tonto Basin, either. Will Lake Mead empty out before “statistically” filling back up? Will Phoenix have 140-degree highs before this current “statistical swing” reverses course? I’d like his guess on that.

This new forced exodus will be eastward. But don’t worry, folks! China neatly packs nearly all its billion inhabitants roughly east of the Yellow River, as their western deserts are uninhabitable.

So, the real question is, if you deny humans are causing warming, when do you think the reversal will start? What if nature decides to go with a familiar, geologic clock and drag this out for another 200 million years?