Changing Lightbulbs Didn't Work

Almost a year ago, in May of 2015, I wrote a piece I called '404 Why it's a Bad Number'. At the time the Keeling Curve observations of atmospheric CO2 concentration at Mauna Loa showed weekly averages in April of 403.5ppm with some daily recordings over 404.

Over the last couple of decades the CO2 concentration has been rising at a rate of about 2ppm per year but the increase from 2014 to 2015 was almost 3ppm. We need to wait till mid May to be sure of this year's increase but it looks like another 3ppm increase.  The last few days, however, have been something else. For four days the average has been about 409ppm with the recordings showing over 410 at times. This is a real outlier from the trend, more than 5ppm above the highest measurement from last year.

Human emissions from fossil fuel burning have levelled off, albeit at record highs, so the simplistic expectation would be for concentrations to keep rising at about 2ppm/year. However, increased forest and peatland fires and melting permafrost are increasing CO2 sources. Warmer sea surface temperatures reduce the CO2 absorption rate.  This year's El Niño won't have helped with warmer Pacific surface temperatures and the likely slow down in plant growth through the year.

Even with flat anthropogenic emissions we should expect atmospheric CO2 concentration to continue increasing at an increasing rate.  Since the CO2 concentration is the primary driver of global warming it should be clear that we are losing the battle. Talk of limiting warming to 1.5° or even 2° is just so much whistling in the wind. We have failed. 

We have failed but if we give up on climate change mitigation now the failure will be a whole lot worse and hit us a whole lot faster.