Planet Earth has reached a new record thanks to two centuries of burning coal and other fossil fuels.
For the first time in history, well human history anyway, the daily mean concentrations of carbon dioxide in the atmosphere reached 400 parts per million. The reading came at the National Oceanic and Atmospheric Administration’s Observatory, near the top of Mauna Loa on the big island of Hawaii.
Scientists there have been measuring carbon dioxide since 1958 and the 400 reading is the highest yet. You should care because carbon dioxide is the major greenhouse gas that has been warming the planet for more than a century, leading to all kinds of climate changes.
I said it was the first time in human history CO2 levels have been so high but Plant Earth has seen it before, two to three million years ago. It was a lot warmer then.
Scientists have been warning us for more than a decade that we face the potential of dramatic climatic changes after we passed 350 ppm. No one really knows since we’ve never been here before. But the fear is that eventually temperatures warm to the point they change the carbon cycle so the Earth releases more carbon than it captures.
We already have warmer rivers, earlier runoff, lower flows in late summer and fall, more and larger wildfires, warmer winters and in Idaho at least, good red wines.