Killing Gaia
Carbon dioxide in the Earth’s atmosphere has just reached 415 parts per million, the highest in human recorded history.
Individual measurements of carbon dioxide in the Earth’s atmosphere, at Mauna Loa in Hawaii, started to pass the 410 parts per million (ppm) line back in 2017. By May 2019 we have had a full five months where the monthly average has been well above 410 ppm. This week we started to see reports that the 415 ppm mark had already been breached. Before we started to burn fossil fuels, CO2 in the atmosphere was about 280 ppm. We passed the 400 ppm mark in 2013, and the graph is rising as steeply now as it ever has.
The last time atmospheric carbon dioxide levels were this high, sea levels were 20 metres (65 feet) higher than they are now, and trees were growing in Antarctica. That was three million years ago.
I used to work as a control system design engineer, and temperature control was our biggest market area. With any oven or kiln, when you switch on full heat and look at the temperature graph, the first thing you see is… absolutely nothing happening. This is what makes controlling a kiln interesting. With a car on the road, you put down the accelerator or the brake, and immediately see a change in speed. Temperature time delays are due to heat ‘hiding’ in places like the heating elements and the oven walls.
The other interesting feature is that, after you have been heating an oven at full power for a while and you switch off the heater, the next thing you see on the graph, again, is that absolutely nothing changes: the temperature continues to rise just as steeply as before. In a large, powerful oven, this can continue for quite a while before eventually levelling off and beginning to fall. These large overshoots are normal for any complex system.
The Earth is far bigger and more complex than any industrial furnace. There are many more places for heat to ‘hide,’ such as the oceans, the poles and so on. There are also complex feedback mechanisms including changes in surface colour as ice melts, and gases being released by seawater, soil and permafrost.
Due to subtle interactions between forests, sea-life, ocean currents and weather patterns, there are also tipping points beyond which temperatures may never recover.
Our global carbon dioxide ‘blanket’ is certainly trapping heat in, warming the Earth, but as yet we have seen only a fraction of the full effects that our disturbances have caused. The only way to ensure that future generations inherit a liveable landscape is to reduce those emissions to zero in just a few years, then plant trees, trees and more trees, while leaving the oceans to recover too. We need to get the CO2 levels back down into the low 300s ppm in just a few decades, before the full global warming effects really take hold.
This article first appeared in the Jersey Evning Post during week ending 17 May 2019
