The Great Global Warming Swindle - Stepham Harrison responds

Stephan Harrison

15th March, 2004

The Channel 4 documentary, ‘The Great Global Warming Swindle’, put forward the idea that carbon dioxide did not in fact cause global warming, but instead was a product of global warming. It also suggested that the Earth frequently enters cold and warm periods of climate, and that the current warming was simply a natural phenomenon. We put these arguments to Stephan Harrison, an Associate Professor in Quarternary Science at Exeter University and a Senior Research Associate at Oxford University…

The basis for our understanding and attribution of contemporary global warming is that carbon dioxide is a major greenhouse gas whose addition to the atmosphere would, in the absence of cooling drivers, be expected to lead to planetary energy imbalances and therefore warming.

With atmospheric carbon dioxide at levels not seen for at least 600,000 and possibly 25 million years, the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4) argued that the observed warming was very likely (greater than a 90 per cent probability) the result of human emissions of carbon dioxide and other greenhouse gases.

However, an important claim in the Channel 4 Great Global Warming Swindle was that at the termination of glaciations in the past, atmospheric levels of carbon dioxide lag rather than lead temperature change, and that this invalidates the idea that carbon dioxide is a major driver of climate change. Rather, the programme’s argument was that atmospheric carbon dioxide responds to temperature change and it used the geological record of changes in carbon dioxide and global temperature in support of this. It is therefore worth assessing the nature of the change in these...

To view the rest of this article - you must be a paying subscriber and Login