Climate Criminals to push us over a Cliff: PWC report

A 4^o C global warming is double the threshold climate scientists will say must not be crossed to avoid disastrous impacts of climate change within this century and beyond.  It will take a massive, concertized international effort by both developed and developing nations to stop short of this ‘climate cliff.’

From Joe Romm at Climate Progress (Study: We’re Headed To 11°F Warming And Even 7°F Requires ‘Nearly Quadrupling The Current Rate Of Decarbonisation’):

A new report by PricewaterhouseCoopers finds humanity has its foot on the accelerator as we head toward a cliff. The only hope is very rapid deployment of carbon-free technology starting ASAP.

The title of the PWC report is sobering, “Too late for two degrees?” So is its main conclusion:

Our Low Carbon Economy Index evaluates the rate of decarbonisation of the global economy that is needed to limit warming to 2^o C. This report shows that global carbon intensity decreased between 2000 and 2011 by around 0.8% a year. In 2011, carbon intensity decreased by 0.7%. The global economy now needs to cut carbon intensity by 5.1% every year from now to 2050. Keeping to the 2^o C carbon budget will require sustained and unprecedented reductions over four decades.

Governments’ ambitions to limit warming to 2^o C appear highly unrealistic.

Included in this sobering study is this handy chart, which conceptualizes the carbon emissions path necessary to avert disaster, according to many scientists, by holding global warming to below 2^o C.  The red line represents our current emissions pathway into oblivion.  Although in the last decade many nations have made significant strides to reduce their energy related emissions, it is still not enough.  The gray line then represents the optimal “low carbon pathway for the 21^st century.”  This option would have required the world to reduce carbon emissions by 3.7% each year from 2000-2050.  As you can see, the world has clearly not met this level of reduction, but exceeded it a great deal.

Romm also goes into detail about what this level of warming might mean for future generations in the US, tantamount to planning for the end of civilization as we know it by 2050 and beyond:

Such a world would likely mean:

• Permanent Dust Bowl conditions over the U.S. Southwest, parts of the Great Plains and many other regions around the globe that are heavily populated and/or heavily farmed.
• Sea level rise of some 1 foot by 2050, then 4 to 6 feet (or more) by 2100, rising some 6 to 12 inches (or more) each decade thereafter
• Massive species loss on land and sea — perhaps 50% or more of all biodiversity.
• Much more extreme weather

These will all be happening simultaneously and getting worse decade after decade.

A 2009 NOAA-led study found the worst impacts would be “largely irreversible for 1000 years.”