March 28th, 2020 by Carolyn Fortuna

The levels of the heat-trapping gas called carbon dioxide have gradually risen and fallen during the past 800,000 years — that is, until recent decades, when carbon dioxide levels shot up far higher than in the past.

Why have the carbon dioxide levels jumped so much in our own lifetimes? Here’s a quick explanation and one that’s handy when we’re chatting with people who insist that the climate crisis is just one more in a series of atmospheric shifts — nothing to look at here, move along.

Small Changes to the Earth’s Orbit & the Tilt of its Axis

Tiny wobbles caused by the gravitational tugs of the sun, moon, Saturn, and Jupiter can slightly alter the amount of sunlight reaching our planet. Even minimal shifts in the amount of energy reaching the planet can cause climate transformations that reveal themselves over millennia.

These…