Avoiding dangerous climate change

Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilisation of Greenhouse Gases was a 2005 international conference that examined the link between atmospheric greenhouse gas concentration, and the 2 °C (3.6 °F) ceiling on global warming thought necessary to avoid the most serious effects of global warming. Previously this had generally been accepted as being 550 ppm.

The conference took place under the United Kingdom's presidency of the G8, with the participation of around 200 'internationally renowned' scientists from 30 countries. It was chaired by Dennis Tirpak and hosted by the Hadley Centre for Climate Prediction and Research in Exeter, from 1 February to 3 February.

The conference was called to bring together the latest research into what would be necessary to achieve the objective of the 1992 United Nations Framework Convention on Climate Change:

It was also intended to encourage further research in the area. An initial assessment of the subject had been included in the 2001 IPCC Third Assessment Report; however, the topic had received relatively little international discussion.

Specifically, the conference explored three issues:

Among the conclusions reached, the most significant was a new assessment of the link between the concentration of greenhouse gases in the atmosphere and the increase in global temperature levels. Some researchers have argued that the most serious consequences of global warming might be avoided if global average temperatures rose by no more than 2 °C (3.6 °F) above pre-industrial levels (1.4 °C above present levels). It had generally been assumed that this would occur if greenhouse gas concentrations rose above 550 ppm carbon dioxide equivalent by volume. This concentration was, for example, informing government in certain countries, including the European Union.

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