Global greenhouse gas emissions accelerated to drastic levels at the start of the century despite an increased number of policies directed at mitigating global warming, the United Nations' top panel on climate change says.
In a report released Sunday, the Intergovernmental Panel on Climate Change (IPCC) warned world leaders that the use of low- or zero-carbon energy sources must be tripled by 2050 to prevent catastrophic damage.
“Climate policies in line with the two degrees Celsius goal need to aim for substantial emission reductions,” said Germany's Ottmar Edenhofer, one of three co-chairs who sits on the panel's working group.
“There is a clear message from science: To avoid dangerous interference with the climate system, we need to move away from business as usual.”
The 37-page report to policymakers analyzed 1,200 scenarios from scientific literature, which were formed by 31 modeling teams across the globe.
"The newest IPCC report shows a wide range of options to cut carbon pollution, including the use cost-effective clean energy. The longer we wait to act, the harder and more expensive it will be," Sen. Barbara BoxerBarbara BoxerCarly Fiorina 'certainly looking at' Virginia Senate run Top Obama adviser signs with Hollywood talent agency: report Democrats vie for chance to take on Trump as California governor MORE (D-Calif.), a vociferous advocate for policies aimed at curbing emissions, said in a statement on Sunday.
While the report offers no hard estimate of the costs countries may incur to limit emissions, it states consumption growth in a vigorous mitigation scenario would fall by roughly 6 percentage points in one year.
"Many different pathways lead to a future within the boundaries set by the two degrees Celsius goal,” Edenhofer of the climate panel said. "All of these require substantial investments. Avoiding further delays in mitigation and making use of a broad variety of technologies can limit the associated costs.”
Those pathways include cutting emissions from energy production and use, transpiration, buildings, and industry.
Carbon emissions from fossil fuel industrial uses contributed roughly 78 percent to the total greenhouse gas emissions increase form 1970-2010.
The greatest drivers of the carbon emissions from fossil fuel combustion, which comes from oil and gas, natural gas, coal, and nuclear sources, were population and economic growth, the U.N. climate panel concludes.
"Increased use of coal relative to other energy sources has reversed the long‐standing trend of gradual decarbonization of the world’s energy supply," the report states.
Cutting emission from coal-fired power plants has become a point of contention in the United States as President Obama's climate change agenda seeks to reign in pollution from the energy source.
Republicans and a number of pro-energy Democrats continue to push back against Obama's carbon emissions regulations for new and existing power plants. The climate panel's finding are not expected to go over well with pro-coal lawmakers who argue that if developing countries are increasing their intake of the source, the U.S. should not hurt certain states' economies to reduce its emissions.
So far, green groups have cheered the report, calling it another wake-up call.
“The IPCC is telling us in no uncertain terms that we are running out of time -- but not out of solutions -- if we are to avoid the worst effects of climate change. That requires decisive actions to curb carbon pollution -- and an all-out race to embrace renewable sources of energy. History is calling," Frances Beinecke, president of the Natural Resources Defense Council, said in a statement.
And international companies like Coca-Cola, Shell, Tesco and Unilever also welcomed the report.
The move by oil giant Shell to join a group of companies in the battle against climate change drew attention last week.
The coalition of leading businesses were brought together by the Prince of Wales's Corporate Leaders Group.
“Many leading businesses are well aware of the need for a collective wake-up call," said Eliot Whittington, deputy director of the leaders group, citing a document more than 90 companies have signed, committing to prevention measures.
"Specifically, the signatories urge policy makers to take a number of significant actions in line with the science of the IPCC, including setting a timeline for phasing out greenhouse gas emissions before the end of the century, designing a credible strategy to transform the energy system, and creating a plan to manage reliance on fossil fuels, especially coal.”
--This report was updated at 1:24 p.m.