Photo by NASA Goddard Space | CC BY 2.0
Politicians recently visiting western Montana’s Lolo Peak fire tried to put the blame for the fire on lawsuits filed by environmentalists. Montana’s US Senator Steve Daines did mention the role of climate change, but quickly went on to say that the climate has always changed.
Well, yes, for sure. Changes in Earth’s temperatures and resulting climate have often been driven by forces beyond human control, and many such changes occurred well before humans existed. These familiar natural forces have changed the climate from hot to cold and from cold to hot, all without a lick of help from man, woman or child.
For example, it’s become plain that large volcanic eruptions can cast killing chills across the planet, crushing crops and making people miserable. For another example, El Niño—perhaps the most widely known expression of natural variability—periodically releases ocean heat that has a rippling effect across much of the planet.
So, yes, Daines’ remark wasn’t entirely hot air. Natural forces are clearly capable of changing the climate.
A recent attention-getting study turned up evidence that an earlier planetary hot spell was driven by volcanic magma under an extensive Siberian coalfield. Geologists put that initial study to the test and have twice confirmed that the hot magma scorched the coal above, thereby releasing lots of carbon into the atmosphere, which then increased atmospheric and oceanic temperatures. The resulting heat created extinctions long before there were humans to blame.
It’s the real world out there, with more than one thing going on at a time, so it’s no shocker that the forms of natural variability don’t always act alone.
One recent study cites evidence that natural variability in the form of a sulfur-loaded volcanic eruption may have had its cooling influence on North America complicated by the warming influence of another natural variation, El Niño.
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