The world will need to quickly slash carbon dioxide emissions and drastically scale up low-carbon infrastructure investments over the next decade to limit and mitigate the impacts of climate change, according to a new report by the Intergovernmental Panel on Climate Change, or IPCC.
"The report shows that we are at the crossroads and what is going to happen from now until 2030 is critical, especially for CO2 emissions," Valérie Masson-Delmotte, a scientist and one of the authors of the "IPCC Special Report on Global Warming of 1.5 degrees C," said in an Oct. 7 news conference. The report was released Oct. 8.
Making the necessary investments and other changes will require require nations, local governments and the private sector to step up on an unprecedented scale and curb emissions beyond the levels nations pledged to make under the Paris Agreement on climate change, the report said. Although the IPCC does not do its own research, the group perform a rigorous peer review of all of the latest scientific papers and research available, about 6,000 scientific papers in this case. More than 90 authors and review editors from more than 40 countries prepared the report.
The IPCC reports are highly respected among the scientific community, and the group's findings have influenced climate change conversations with governments and others over the years, said Alden Meyer, director of strategy and policy at the U.S. advocacy group Union of Concerned Scientists.
President Donald Trump has pledged to withdraw the U.S. from the Paris accord, which aims to limit global warming to no more than 2 degrees C from pre-industrial levels. But a number of U.S. states and businesses have vowed to continue to pursue the goals of the agreement.
The report finds it is possible to limit global warming of 1.5 degrees C from pre-industrial levels, which is an aspirational goal of the Paris Agreement, and that doing so would make the world a much easier place to live in than under a 2 degrees C scenario. Under a 1.5 degree C scenario compared to half a degree warmer, coral reefs could be saved; about 10 million fewer people would be exposed to sea-level rise related risks; and water-supply challenges and the number of species projected to lose over half of their geographic range would both be reduced by 50%, the report said.
"Limiting warming to 1.5 degrees C is possible within the laws of chemistry and physics but doing so would require unprecedented changes," said Jim Skea, co-chair of one of the IPCC's working groups.
However, "the report has sent a very clear message that if we don't act now and have substantial reductions in carbon dioxide emissions over the next decade, we are really making it very challenging to impossible to keep warming below 1.5 degrees," Skea said. Not only could delaying action mean there will be fewer options to choose from but the world also risks locking in carbon-emitting infrastructure or creating stranded assets, the report said.
The report finds that limiting global warming to 1.5 degrees C would require "rapid and far-reaching" transitions in land, energy, industry, buildings, transport and cities. Global net human-caused emissions of carbon emissions would need to fall by about 45% from 2010 levels by 2030, reaching net zero levels around 2050. "This means that any remaining emissions would need to be balanced by removing CO2 from the air," said a press release on the report. The report comes even as global emissions climbed in 2017.
Limiting global warming to 1.5 degrees C would require a "rapid and profound" near-term decarbonization of energy supplies, specifically scaling up renewables and sustainable biomass, the quick deployment of carbon capture and sequestration leading to a zero-emissions energy supply system by midcentury, the report said. By 2050, renewables would need to supply 70% to 85% of electricity globally, there would be no coal-fired generation without carbon capture and sequestration, and natural gas combined with carbon capture and sequestration could make up about 8% of electricity supplies. The transportation sector and residential energy usage for heating would need to switch from fossil fuels to electricity.
The average annual investment in low-carbon technologies and energy efficiency would need to double in the next 20 years and by 2050 would need to be scaled up by roughly a factor of five compared to 2015 levels, according to the report. In other words, the world would need be making about $900 billion a year in low-carbon energy and efficiency-related investments by 2050, the report said. The report and scientists acknowledged that there is limited literature on how much would need to be spent on mitigation.