Limiting global warming to 1.5°C will require extreme changes, including markedly increasing the percentage of electricity from renewables by mid-century, according to a Sunday report from the United Nations’ Intergovernmental Panel on Climate Change (IPCC).
The report, commissioned as part of the 2015 Paris climate agreement, presents a stark portrait of the future unless the world undertakes “rapid, fair-reaching and unprecedented changes in all aspects of society” in the next decade or so — changes that thus far have been difficult for decision-makers to agree on.
“The report shows that we only have the slimmest of opportunities remaining to avoid unthinkable damage to the climate system that supports life as we know it,” said Amjad Abdulla, an IPCC board member and chief negotiator for the Alliance of Small Island States.
Citing over 6,000 scientific reports and using contributions of 91 authors, the report’s pathways to limit warming vary. But all include increased levels of clean energy. Most show drastic reductions in coal and oil.
The report includes a wide array of possible scenarios that would draw down emissions and keep warming below 1.5°C, including bumping the share of renewables in electricity to 97 percent in the most aggressive forecast. In a sampling of three scenarios the IPCC selected to show a wide range of possible climate mitigation approaches, renewables range from a 63 to 77 percent share of electricity by mid-century. The IPCC also included one scenario that would overshoot the 1.5°C target.
The middle range of the IPCC’s scenarios, where there is little to no overshoot, require that renewables make up 70 to 85 percent of electricity by 2050.
Within the same middle range of scenarios, primary energy from coal drops to 1 to 7 percent, and oil declines to 32 to 74 percent between 2020 and 2050. Use of natural gas would have to drop to between 13 and 60 percent over the same time period, but some scenarios increase gas in combination with carbon capture and sequestration (CCS). Authors pair coal with CCS as well, but note that its use hinges on technological advancements and incentives for deployment at a large scale.
Most 1.5°C pathways include an increased role for nuclear power, in one case up to 501 percent above 2010 levels by 2050. But in certain circumstances, nuclear power decreases.
The report also touches on the potential of clean energy technologies such as energy storage to ease the transition, though the authors note that “the feasibility of battery storage is challenged by concerns over the availability of resources and the environmental impacts of its production.”
Ravi Manghani, director of energy storage at Wood Mackenzie Power & Renewables, said the significant transition presented in the report will stretch the current bounds of storage technology.
“The level of carbon-free generation needed to meet the 1.5°C pathway will need more than lithium-ion batteries, even if resource constraints can be resolved,” said Manghani. “The electricity system would require awfully large amounts of long-duration storage, and a shift toward pumped hydro, or chemical storage solutions like natural gas, synthetic from renewables with CCS, hydrogen and others.”
The report elicited dramatic response, with leaders such as Andrew Steer, president and CEO at World Resources Institute, calling it “a wakeup call for slumbering world leaders.” Former Chilean president Ricardo Lagos said it details a threat that "cannot be understated."
And though the comprehensive report presents a jarring portrait of the future, many of its general takeaways — including the disproportionate impact of climate change on marginalized groups and the need to drastically reduce emissions — have been accepted for years
Global leaders and climate activists have held up the dire consequences of climate change for decades, with many businesses more recently joining the refrain. Still, action so far has been haltingly slow.
“This report is not a wakeup call,” said former Norwegian Prime Minister Gro Harlem Brundtland. “It is a ticking time bomb. Climate activists have been calling for decades for leaders to show responsibility and take urgent action, but we have barely scratched the surface of what needs to be done.”
According to the International Energy Agency, renewables accounted for just 23 percent of electricity in 2015. Increasing clean energy adoption at the rate the report calls for will require $2.4 trillion in investment every year. Bloomberg New Energy Finance logged clean energy investments at just $138.2 billion for the first half of 2018.
While businesses, sub-national governments and many countries have committed to climate action, and achieved some progress — see the $9 trillion We’re Still In Campaign — slow movement from those that profit off fossil fuels and staunch resistance from parties like the Trump administration have made collective action difficult.
Days ahead of the IPCC release, for instance, the conservative, climate-change-denying Heartland Institute circulated a pro-fossil-fuel report from the Nongovernmental International Panel on Climate Change (a group whose scientific rigor has long been questioned) that contends that “the global war on fossil fuels...was never founded on sound science or economics.”
It’s unclear whether the dramatic conclusions of the IPCC’s fact-based report can overcome climate denial and galvanize the type of change it calls for. Global leaders will gather in Poland in December for the next round of climate talks. According to the IPCC, “the next few years are probably the most important in our history.”