The world risks blowing through its carbon budget in 21 years, threatening to cause global warming of more than double the threshold deemed safe by the United Nations, the global accounting firm PwC said today in a study.
The budget is the amount of greenhouse gases the world can emit by 2100 to cap the temperature rise at 2 degrees Celsius (3.6 degrees Fahrenheit). CO2 emitted per unit of economic output fell at 0.7 percent per year from 2007 through 2012, less than an eighth of the required rate now needed, PwC said.
“G20 countries are still consuming fossil fuels like there’s no tomorrow,” PwC Sustainability & Climate Change Director Jonathan Grant said in an e-mailed statement. “The results raise real questions about the viability of our vast fossil fuel reserves, and the way we power our economy. The 2-degrees carbon budget is simply not big enough to cope with the unmitigated exploitation of these reserves.”
World leaders endorsed the 2-degree target as the scale of temperature increase from the start of the industrial era that’s acceptable before more dangerous impacts occur. Those include rising seas, more intense storms and shifting rainfall patterns.
Envoys from 190 nations are aiming to craft a treaty by 2015 that will put the planet on a path to limit warming to 2 degrees. The pact would replace the Kyoto Protocol, which was negotiated in 1997 and regulates the greenhouse gases in a group of industrial nations that now are responsible for less than 15 percent of global emissions.
A number of “silver bullets” identified for large-scale decarbonization, including nuclear power and carbon capture and storage, appear to be failing, PwC said. Cheap shale gas, which has helped lower U.S. emissions by replacing coal, displaced dirtier coal to other markets, including Europe, according to the consultant.
Among G20 nations, Argentina, the U.S. and Australia achieved the biggest average annual reductions in the carbon intensity over the 5 years through 2012, PwC found. Intensity rose in Saudi Arabia, Brazil, South Korea, Mexico and Japan.
PwC used carbon figures outlined in a report in September by the UN’s Intergovernmental Panel on Climate Change. Under a scenario outlined there that would keep temperature gains below 2 degrees, countries can emit about 270 billion tons of carbon through 2100.
To achieve that, they would need to decarbonize at 6 percent a year, PwC said. Even doubling the current rate to 1.4 percent a year would lead to warming of more than 4 degrees.
“On current trends we will use up this century’s carbon budget by 2034 -- sixty six years early,” Leo Johnson, a partner at PwC, said in the report’s foreword. “Put simply, we are busting the carbon budget.”