Carbon-dioxide levels haven’t been this high in at least 800,000 years


Koch Bros coke alongside the Detroit River

Since 1958, the Mauna Loa Observatory in Hawaii has tracked the rise of carbon dioxide in the atmosphere — the simplest measure of how humans are altering the Earth and warming the planet.

This “Keeling Curve” reached a new milestone in April: the amount of carbon dioxide in the atmosphere remained above 400 parts per million for the entire month (an average of 401.25 ppm). That’s the first time that’s happened in recorded history…

Last year, carbon-dioxide levels rose briefly above 400 parts per million for a single day in May before falling again. This year, they spent an entire month above 400 ppm — and will likely drop again this summer. In a few years, so long as humans keep burning fossil fuels, we should get above 400 ppm permanently.

Is 400 ppm an important milestone?

By itself, probably not — it’s more notable as an indication that carbon-dioxide levels are going up and up, which will set the stage for future global warming.

The broader historical picture is a bit more relevant here: In recent decades, carbon-dioxide levels have remained higher than at any point in 800,000 years. Scientists figured this out by analyzing prehistoric air bubbles that had been trapped in ice cores…

Indeed, some studies go further and estimate that carbon-dioxide levels may be at their highest point in 4.5 million years. During the Pliocene era, scientists have found, carbon-dioxide levels appeared to be around 415 ppm…

We have to go back 4.5 million years to find an analogue to the present day…

What’s also relevant, climatologists note, is the speed of change — the Earth is blowing past 400 parts per million today much faster than it did in the past. That makes it more difficult for species to adapt to the accompanying temperature increases (including, for that matter, humans).

So how high will carbon-dioxide levels rise?

That’s the big unknown. The Intergovernmental Panel on Climate Change says that we should stabilize levels at somewhere between 430 and 480 ppm if we want a good shot at keeping total global warming below 2°C — which is ostensibly the international goal. For reasons I laid out here, that scenario looks increasingly unlikely…

RTFA and examine a practical, achievable list of means and methods to remedy the situation. Then, reflect upon the knuckle-dragging populists who react to Pavlovian commands from pigs like the Koch Bros to oppose not only positive and forward-looking change; but, do their worst to push every industrial nation into exacerbating our climate questions.

For questions they are – not problems. Answers are ready and at hand. Only the politics of stupid prevent implementation.