David Archibald
Thanks to Modtran, an online program maintained by the University of Chicago, we know that the heating effect of carbon dioxide is logarithmic. The first 20 ppm of carbon dioxide heats the atmosphere by 1.5°C. At the current concentration of 412 ppm, each additional 100 ppm is only good for 0.1°C. Carbon dioxide is hidden away as a greenhouse gas.
But what about methane gas as an excuse to destroy livelihoods, towns, industries, and entire economies? Methane, with a half-life of nine years in the atmosphere, is the younger brother of carbon dioxide in the pantheon of satanic gases.
Witness this headline on New Zealand antics:
we return Modtran to see what that prophet will tell us about the heating effect of methane. Here is the model output converted to degrees Celsius:
Although not as pronounced as the decrease in the heating effect of carbon dioxide with concentration, the effect is still there such that at the current concentration of 1.9 ppm, each additional 0.1 ppm will heat the bulb. atmosphere by 0.05°C. With methane concentrations currently increasing by 0.1 ppm every 20 years, the atmosphere will warm by 0.2°C by 2100. Readers can decide if they need to worry by the forecast. this newspaper.
But methane has only increased at that rate for a few years. Atmospheric carbon dioxide concentrations have been measured since 1958. Methane measurements only started in the mid-1980s, and here’s what the data looks like:
There was a sharp increase at first but then from the early 1990s to 2010, the concentration stayed flat for almost 20 years. Cape Grim concentrations are particularly flat. NASA has provided a helpful rate-of-change chart:
There were three years – 2000, 2001 and 2004 – in which methane levels dropped. Let’s ignore the noise and see the bigger picture more clearly. And that’s the rate of growth for 20 years and then for 20 years. A few more decades of observations could show whether this is a cycle.
But farms that have been around for generations could be wiped out due to unnecessary concerns about methane while we wait for that data. So we’re going to take a stab at basic science. Two factors are likely related.
First, the plant’s productivity has increased with an increase in the concentration of carbon dioxide in the atmosphere. Parts of the Western Australian desert are now 30% more vegetated than 30 years ago. The same is true of the vast expanse of forests and tundra across northern Russia. Unless this vegetation is consumed by fire, it is destined to become a source of methane through termites or rotting. So the human hand is not necessarily involved in the increase in methane levels.
Second, the Sun is more active in the second half of 20order century compared with eleven thousand years ago. That stopped in 2006 with the end of the Modern Warm Period. The Sun has become less active as the Sun’s extreme ultraviolet chart created by the University of Bremen:
Our current solar cycle, 25, is tracking lower than any of the previous four. Methane’s natural enemy is ozone, the most reactive gas in nature. Ozone is produced in the upper atmosphere by radiation with wavelengths less than or equal to 242 nanometers acting on oxygen. So less ozone has been created since 2006 and this is when atmospheric methane levels stopped falling and started rising again.
Closed case. Nothing to see here. Move along. Only fools are affected by a very small effect that we can’t change anyway. There are real problems with humanity that will capture all of our attention. Destroying the production facility in the interim will only make our situation worse.
David Archibald is the author of Cancer garden in Australia
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