The world four degrees warmer: flooded, starving, and broke

Scientists have warned that increases in global average temperatures of four degrees Celsius, resulting in drought, desertification and rapid sea level rise, could be terrifyingly real by 2060.

A lack of progress towards a global deal to curb greenhouse emissions means the target agreed at last year’s Copenhagen Summit of limiting average temperature rise to two degrees is now almost impossible to achieve, according to a special series of journal papers published by the Royal Society.

The international study team behind the research wrote that increasing greenhouse gas emissions over the coming decade rendered the two-degree target “extremely difficult, arguably impossible, raising the likelihood of global temperature rises of three or four degrees Celsius within this century”.

The research comes just days after the Met Office released a report warning that the world has warmed more quickly than was previously thought over the past decade. A series of further studies have predicted over the last week that 2010 is likely to be the joint hottest year on record.

The latest research published by the Royal Society analysed the non-binding emission pledges made at the Copenhagen summit a year ago based on actual tonnes of emissions, rather than percentage reductions. It concluded that the cuts are not deep or rapid enough, and projects a nightmarish scenario where food supplies collapse, leaving millions of migrants seeking refuge across the globe.

Scientists at Oxford University warned that the sheer speed of temperature increases could outstrip nature and civilisation’s adaptation efforts. “Dangerous climate change depends on how fast the planet is warming up, not just how hot it gets,” Myles Allen, of the university’s department of Physics, told the Guardian. “It’s not just how much we emit, but how fast we do so.”

Another paper estimated that sea levels might rise by between 0.5 and 2 meters by 2100 if temperatures rose four degrees Celsius. It warned that such a scenario would require annual investments of up to $270bn a year to help economies adapt.

“Drought and desertification would be widespread … There would be a need to shift agricultural cropping to new areas, impinging on [wild] ecosystems,” said Rachel Warren from the University of East Anglia, in a paper contributed to the series. “Large-scale adaptation to sea-level rise would be necessary. Human and natural systems would be subject to increasing levels of agricultural pests and diseases, and increases in the frequency and intensity of extreme weather events.”

While the prospect of a four-degree rise is seen as extreme, researchers argue that it is becoming more plausible with the current trend of ever-rising emission with no global deal to limit them.

Negotiations begin today in Cancun, and the papers’ authors called on governments to take stock of the progress made so far, and move quickly to cut emissions and increase investment geo-engineering projects, such as artificial trees that suck carbon from the atmosphere.

“This paper is not intended as a message of futility, but rather a bare and perhaps brutal assessment of where our ‘rose-tinted’ and well-intentioned approach to climate change has brought us,” Anderson wrote in the report. “Real hope and opportunity, if it is to arise at all, will do so from a raw and dispassionate assessment of the scale of the challenge faced by the global community.”

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