History Matters: Carbon Emissions in Context
Posted on 6 July 2011 by Stephan Lewandowsky
A short piece for the general audience of RTR radio, Perth, Australia.
(listen to the original audio podcast)
We often hear that our CO2 emissions are such a tiny fraction of the world’s total, around 1.5%, that there is no need for us to take action. If we are only responsible for such a small proportion, why should we bother with a carbon tax?
Is there any validity to this argument?
Not really. In fact, not at all.
And to understand why, we need to understand the basics of carbon emissions. The key to understanding what is happening with carbon in the atmosphere is your bathtub at home—because the atmosphere is just a bathtub that are currently filling with extra CO2, in the same way that you fill your bathtub by turning on the tap.
Suppose you’ve been drawing water into your bathtub for 5 minutes and it’s close to full. All of a sudden your neighbour shows up and empties a bucket of water into the tub.
Who bears the greatest responsibility for the water in your tub? Your tap that ran for 5 minutes or your neighbour’s one bucket?
Obviously, it’s you, and not your neighbour, despite the fact that for the last few seconds, his bucket made a much bigger splash than your tap.
The same applies to carbon emissions: If we want to assign responsibility for global warming, we must look at the sum total of emissions across the last few hundred years. What matters isn’t just what we emit today, but what we have emitted for hundreds of years.
Because the atmosphere is a bathtub for CO2.
And guess what, if we compare emissions among the roughly 200 countries in the world, then we find that all but 14 of them have pumped less carbon into the atmosphere than Australia. Yes, we are the 14th-largest historical emitter in the world. We therefore shoulder greater responsibility for global warming than more than 90% of the countries in the world.
The 21 million of us shoulder a greater responsibility for global warming than any one of the lesser emitters whose combined population exceeds 3 billion people.
So of course we need to live up to that global responsibility by cutting emissions. We wouldn’t want to be a free-riding global dole bludger, after all.
This is the text of a 3-minute climatecast that initially aired on Perth’s RTR-FM 92.1. All our climatecasts are now available also as a regular podcast in the iTunes store — just search for “Climate Podcasts from the University of Western Australia” in the iTunes store. Alternatively, you can subscribe to the stream via feedburner.
A more extended version of this particular climatecast, with the data analysis on which this post is based can be found at Shaping Tomorrows World. Note: this post was initially (accidentally) posted on SkS on June 8 but only aired on RTR today on July 6.