Avoiding Dangerous Climate Change: A Scientific Symposium on Stabilization of Greenhouse Gases was a 2005 international conference that examined the relationship 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 has 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 Center for Climate Prediction and Research in Exeter , from 1 February to 3 February. 
The conference was called to bring together the latest research on what would be needed to achieve the objective of the 1992 United Nations Framework Convention on Climate Change :
- to achieve, in accordance with the provisions of the Convention, the stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system .
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:
- For different levels of climate change what are the key impacts, for different regions and sectors for the world as a whole?
- What would these levels of climate change imply in terms of greenhouse gas stabilization and emission levels?
- What are the options for achieving stabilization of greenhouse gases at different concentrations in the atmosphere, taking into account costs and uncertainties?
Among the conclusions reached, the most important was a new assessment of the relationship between the concentration of greenhouse gases in the atmosphere and the increase in global temperature levels. Some researchers have argued that global warming might be better than 2 ° C (3.6 ° F) above pre-industrial levels (1.4 ° C above present levels). It was generally assumed that this gas concentration rose above 550 ppm carbon dioxide equivalent by volume. This concentration was, for example, informing government in certain countries, including the European Union . 
The conference concluded that, at the level of 550 ppm, it was likely that 2 ° C would be exceeded, according to the projections of more recent climate models . Stabilizing greenhouse gasconcentrations at 450 ppm would have resulted in a 50% likelihood of global warming at 2 ° C, and it would be necessary to achieve stabilization below 400 ppm to give a relatively high certainty of not exceeding 2 ° C. 
The conference also claims that, if action to reduce emissions is delayed by 20 years, the rate of emissions may be higher to meet the same temperature target. 
As a result of changing opinion on the ‘safe’ atmospheric concentration of greenhouse gases, to which this conference contributed, the UK government changed the target in the Climate Change Act from 60% to 80% by 2050. 
- 4 Degrees and Beyond International Climate Conference
- Action on climate change
- Climate change mitigation scenarios
- Environmental impact of aviation
- Hypermobility (travel)
- Index of climate change articles
- Jump up^ “Climate Stabilization Conference – Exeter 2005” . Government News Network . 4 November 2004. Archived from the original on 30 September 2007 . Retrieved 15 March 2007 .
- Jump up^ “Dangerous Avoiding Climate Change – Background” . Met Office . 2005. Retrieved 16 March 2007 .
- Jump up^ “Community Strategy on Climate Change – Council Conclusions” . Council of the European Union . 22 June 1996. Archived from the originalon 28 January 2008 . Retrieved 15 March 2007 .
- ^ Jump up to:a b “International Symposium on the Stabilization of greenhouse gas concentrations – Report of the International Scientific Steering Committee”. Met Office . 10 May 2005. Archived from the original on 18 March 2006 . Retrieved 15 March 2007 .
- Jump up^ “UK leads with commitment to cut emissions by 80% by 2050” . Department of Energy and Climate Change . October 16, 2008. Archived from the original on October 20, 2008 . Retrieved 28 October 2008 .