We need to reduce greenhouse gases in the atmosphere, and we need to do it quickly. The main ones increased by humans are carbon dioxide (CO2), methane (CH4, the main component of natural gas), and nitrous oxide (N2O).
How are we doing?
Let’s start with CO2. Here’s the atmospheric concentration (in ppm, or “part-per-million”) according the the atmospheric observatory at Mauna Loa:
The black line shows the concentration, and reveals a regular up-and-down pattern each year; a seasonal cycle of CO2 at Mauna Loa. The red line show what we get when the seasonal cycle is removed.
Of course we’re most interested in what has happened lately. Here’s the data since the year 2000:
The black line shows the CO2 with the seasonal cycle removed. The red line is a straight-line fit (by least squares regression), which rises at a rate of 2.15 ppm/year. But the data don’t follow that straight line perfectly, especially recently. Here are the residuals, what’s left over if we subtract the straight-line values from the oberved values:
There was a sharp increase of about 2 ppm on top of the already existing trend right around 2016. Part of that is temporary, due to the strong el Niño, but it hasn’t subsided so much of the increase remains.
Bottom line: we haven’t stopped CO2 growth, we haven’t even slowed it.
What about methane? Here’s the atmospheric concentration measured at Cape Grim in Tasmania, Australia:
Here’s what’s happened since 2000:
It had levelled off during the early 2000s, but started rising again about 2007. Lately, there’s no sign of stopping or even slowing.
What about nitrous oxide? Here’s the data from Cape Grim:
Since the year 2000:
Again, no sign that we’ve stopped increasing or even slowed down.
There is, as yet, no sign of any slowdown in the growth of greenhouse gases. That emphasizes how hard this is going to be. But it’s worth it to stave off destruction, destitution, injury and death. That’s what’s at stake.
This blog is made possible by readers like you; join others by donating at My Wee Dragon.