Professor John Shepherd FRS, Ocean & Earth Science at University of Southampton, said:
"Cutting CO2 emissions enough to reduce climate change and ocean acidification significantly is going to be difficult, but the alternatives are not easy either. Adapting to climate change is also going to be expensive, and will not always be possible. None of the proposals for geo-engineering the climate looks like being sufficiently safe or effective either. If we just carry on burning fossil fuels, and suffer the consequences, the impacts will be very serious, especially for people who are poor and vulnerable, and least able to adapt. In practice we shall most likely need to use some mixture of these four possible responses. It is not for scientists to determine policy, but in my opinion cutting CO2 emissions is the safest and most predictable way to respond to man-made climate change. There is no magic bullet for achieving a sustainable and low-carbon economy, and we are likely to need to use many of the available and possible new technologies, as well as new fiscal measures and regulations, and changes of behaviour and lifestyles."
Professor Andrew Watson FRS, Royal Society Research Professor at the University of Exeter, said:
"This is a very responsible report. It has a clear message that there is no painless or risk-free approach to the problem we face. For sure, there are economic and societal risks involved with mitigation approaches, whether these involve reducing fossil fuel burning, or the use of carbon dioxide sequestration and removal techniques. However, there are even bigger risks if we do nothing and rely exclusively on being able to ride out climate change and adapt to it – which is what will happen unless governments take stronger steps to slow the increase of greenhouse gases. We have to encourage both the switch to renewables and pilot projects for carbon sequestration technologies."
More information about the report can be found on the IPCC website.