Carbon dioxide in atmosphere reaches alarming milestone

South Tipperary Green Party chairman Con Trass writes about a dangerous milestone for our planet that’s being reached in the coming days.

South Tipperary Green Party chairman Con Trass writes about a dangerous milestone for our planet that’s being reached in the coming days.

When I was twelve or thirteen in the early 1980s I took part in a charity cycle from Cahir to Clonmel. Back then the cycle seemed quite long, though it probably only took about an hour on my Raleigh Chopper. Nowadays, that ten mile journey does not seem so far.

But what about if you were to take that journey straight up, instead of across the surface of the planet? Just stand outside, and look straight up. At about ten miles up, there is not much air left; in fact, if you cycled ten miles upwards all the clouds, and 80% of the air would be below you at that stage. It gives you an idea how thin the blanket of air surrounding our planet really is.

To put it another way, if you consider a standard classroom globe, the thickness of the atmospheric layer would be equivalent to only about 1 or 2 mm on top of that.

Back when I was cycling in the early 1980s, the atmospheric carbon dioxide (CO2) level was at 340ppm. If I was cycling in the 1780s it would have been about 280 ppm, and not much different in the thousands of years before that since the last ice age.

The rise in atmospheric CO2 between 1780 and 1980 is entirely due to man’s activity, and specifically the burning of fossil fuels such as coal, oil, gas and peat. It is not hard to see that burning all those fossil fuels would have an impact, given how thin our atmosphere is.

In the two hundred years up to 1980, atmospheric CO2 increased by 60 ppm.

In the next few days, atmospheric CO2 will pass the 400ppm mark, representing another 60ppm increase. This time, it took not two centuries, but a little over 30 years. It is clear that mankind is burning more fossil fuel than ever.

The 400ppm CO2 mark is a milestone worth marking. Scientists can tell with certainty that this is a higher level than at any time in the last eight hundred thousand years, and probably higher than at any time in twenty million years. If you consider that modern humans moved from Africa into Europe two hundred thousand years ago, and that Neanderthal man died out only thirty thousand years ago, it gives a context to how quickly our atmospheric CO2 is now changing, after being stable through these hundreds of thousands of years.

Are there consequences to passing the 400ppm mark, and just when will CO2 levels in the atmosphere stop rising?

The answer to the first question is yes, and the consequence is a warming of the planet, broadly called climate change, because not all parts of the planet will be warmed equally. Our current hope is that we may be able to limit the warming to an average of two degrees celcius, though that will require significant reductions in CO2 emissions and fossil fuel use.

The latter question is in our hands, as it is our activities that generate the carbon dioxide. The more energy we use, the more CO2 is added to the atmosphere. Everything we may do, from turning off the lights, to insulating buildings to building windmills to buying less processed (and more locally produced) foods can reduce our CO2 output. So too can leaving the car at home. While my Raleigh Chopper is long since gone, it is perhaps time I went back to the 80s and got on my bike.

By Con Traas, Chairman, South Tipp Green Party.