Race is on to curb climate consequences
15 January 2013, by Alex Peel
Policies that reduce global carbon emissions now can make a real difference to the impacts of climate change by 2100, new research shows. But we are unlikely to see many benefits before 2050.
Carbon emissions from an industrial landscape.
The study, published in Nature Climate Change, suggests that if annual carbon emissions peak by 2016, the consequences of climate change by 2100 would be 20-65 per cent lower than if we'd done nothing to control emissions.
'The sooner you start, the greater the benefits you get at the end of the century,' says lead author Professor Nigel Arnell. 'It's going to take a long time to see the effects of policy in the climate system.'
The effects of limiting temperature rises would not be felt in the same way everywhere. 'If we hit a policy that limits temperature rise to two degrees, which is the target set by the international community, the benefits will be very varied depending on where you are,' says Arnell.
Indeed, in some areas that could benefit from climate change, from fewer floods or greater availability of fresh water, for example, stringent emissions targets might even be harmful.
But this must be weighed against major reductions in adverse impacts elsewhere. If emissions were to peak by 2016 and decline by five per cent a year thereafter, up to 200 million people could be saved from increased risk of river flooding by 2100.
'The sooner you start,
the greater the benefits
you get at the end of
the century'
Professor Nigel Arnell,
Walker Institute,
University of Reading
Building on work commissioned by the NERC-funded QUEST project, which looked to improve understanding of how the Earth system works, the UK Department of Energy and Climate Change commissioned the research in order to assess the consequences of various emissions policies.
Several studies had already used climate models to show how different emission policies could affect global temperatures.
But this new research, carried out by Professor Arnell of the University of Reading's Walker Institute and his team of UK researchers, is the first to translate this into predictions for water stress, flooding, drought, agriculture and energy demands.
The research comes after the latest figures from the Global Carbon Project revealed continuing growth in annual CO2 emissions from fossil-fuel burning, largely due to economic growth in developing countries.
In fact, current trends in global carbon emissions are in line with some of the more extreme projections from the latest Intergovernmental Panel on Climate Change report, giving a global temperature rise of 4°C to 6.1°C above pre-industrial levels by 2100.
Professor Arnell and his team will now expand their analyses to include a wider range of climate change impacts – such as losses from extreme weather events – to build a more comprehensive picture of the effects of emissions policy.
Arnell NW, Lowe JA, Brown S, Gosling SN, Gottschalk P, Hinkel J, Lloyd-Hughes B, Nicholls RJ, Osborn TJ, Osborne TM, Rose GA, Smith P, Warren RF (2013) A global assessment of the effects of climate policy on the impacts of climate change. Nature Climate Change.
Keywords:
Adaptation & mitigation,
Climate system,
Earth system,
Environmental change,
Flooding,
Hazards,
Human health,
Humans,
Natural resources,
Pollution,
Sea level change,
UK,
Weather,
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