No one at last week’s UN climate conference thought the summit would deliver a deal to stop global temperatures rising more than 2 °C – generally considered to be the threshold above which catastrophic consequences are inevitable.
Instead, some called for Plan B: a global pricing system for carbon that is high enough to kill coal once and for all.
Some have claimed the opposite recently, heralding a report by the International Energy Agency finding that global energy-related emissions had not risen for the first time in 2014, even as the economy grew.
But Edenhofer thinks the 2014 figures could well be revised upwards. And even if they’re right, it was probably a blip rather than a turning point, he told New Scientist: “One year is not a good indicator.”
Even if carbon prices were introduced tomorrow, it is unlikely to be enough. Some politicians are still talking about limiting warming to 1.5 °C, but scientists now regard this as fantasy. “I’m struggling for words to characterise the 1.5-degree target,” said Thomas Stocker of the University of Bern, Switzerland. Even the 2 °C target has become “extremely ambitious”, he says.
Just about every scenario leading to 2 °C either assumes global emissions peaked around 2010 – they didn’t – or requires “negative emissions” (see “The dirty secret of 2 °C scenarios“). So achieving it requires either time travel or geoengineering, Kevin Anderson of the University of Manchester told the conference.
Nextbigfuture has indicated that it is ten to twenty times cheaper to reduce soot (soot darkens ice which increases melting and increases temperature by absorbing more heat instead of reflecting it into space).
Warming from soot is nearly equal to current warming from CO2.
There also needs be a massive scaling of nuclear energy.
City scale geoengineering can also be started and other geoengineering tests.
SOURCE – New Scientist