I was researching one of the graphs in the IPCC report for policy makers when I came across two terrifying graphs with a terrifying relationship.
The first graph shows the estimated annual emissions of carbon dioxide as a result of human activity versus the year of emission. The data runs from 1750 until 2010.
The terrifying feature of this graph is that the only events to interrupt the rise are catastrophic events such as world wars, depressions, and the oil crisis of the mid-1970s.
The second graph shows the cumulative total of annual emissions of carbon dioxide as a result of human activity versus the year to date.
The terrifying feature of this graph is its inexorable rise. Even the wars and depressions which are visible in the annual emissions graph are barely detectable.
And the terrifying relationship between the two graphs can be seen if they both plotted together.
This third graph merely confirms that the rate of emission of carbon dioxide is not just increasing, but the rate at which it is increasing is increasing. A curve of this form in which the rate of rise of a quantity increases as the quantity itself rises is called exponential.
It is of course physically impossible for these graphs to continue rising indefinitely: eventually we run out carbon! But we are still hundreds of years away from the limit. What strikes me is that for all our concern about carbon emissions, there is not even a detectable blip on either curve resulting from our goodwill.
And given the scale of events which have affected global emissions in the last 100 years, I really don’t know which terrifies me more: the prospect that we will fail to agree to cut emissions; or the prospect that we will succeed.
- CO2 data is from the Carbon Dioxide Informationa Analysis Center
- My spreadsheet with data and the above figures can be downloaded here :CO2 Emissions spreadsheet