Governments have just five years to cut enough emissions to limit global temperature rise to 1.5°C, and regulation is needed to push key sectors towards positive decarbonization tipping points where “the new technology becomes more attractive than the old,” says a new report from the University of Exeter.
The study [pdf] modelled the impact of three key types of decarbonization policies—regulatory mandates, subsidies, and carbon taxes—across four high-emitting sectors (power, automotive, heavy transport, and heating) in 71 different world regions. The models showed which policies would most effectively bring forward a sector’s positive tipping point, the point beyond which the changeover to low-carbon solutions starts to speed up significantly.
The study also considered the impact of sector coupling, “how change in one sector can have causal effects that encourage change in another.”
Understanding and facilitating those connections will be critical to speed up the still-too-slow energy transition, study co-author Tim Lenton, director of the Global Systems Institute and chair of Climate Change and Earth System Science at the University of Exeter, told attendees at a Sept. 23 launch webinar.
Positive Tipping Points
Unlike negative tipping points like melting polar ice sheets, positive climate tipping points are a very good thing, describing the moment when an event critical to decarbonization becomes “self-propelling,” the report explains. Once a sector hits that point through known processes like learning by doing and achieving economies of scale, the change is well under way and likely to keep going.
The relative cost of clean technologies and fossil fuels is “a critical factor in the pace of the low-carbon transition, affecting affordability for consumers, profitability for businesses, and political feasibility for governments,” the report says. So the point at which clean energy costs the same or less than dirty fuels is an urgent positive tipping point to meet as rapidly as possible.
Bring On the Mandates
Across the four sectors modelled in the study, mandates worked better than taxes or subsidies to bring forward these positive tipping points at the required speed.
“This reflects their (mandates’) ability to force a rapid and large-scale reallocation of investment towards the clean technology,” especially in road transportation and heating, the report says.
Because “subsidies incentivize, rather than force” action, they have a “weaker” impact, but they’re most effective in the heating sector.
“in sectors that are still in the early stages of transition, targeted subsidies might be required initially, to support the first deployment of clean technologies,” the report says. But mandates will probably be needed to achieve widespread adoption.
“Outside of the power sector, the effect of the carbon tax is weaker still (than subsidies), as the cost of carbon relative to other capital and operating costs is modest in these sectors.”
But carbon taxes still have an impact in the power sector, making “onshore and offshore wind more competitive with coal, and having a large effect on emissions.”
Policymakers should also be aware of the “super-leveraging” power of a zero-emission vehicle mandate in light road transport. It’s the policy that has “not only the highest leverage action within its own sector, but also has a significant positive influence on the transition in other sectors.”
A coal phaseout policy “also strongly influences other sectors and could be another super-leverage point,” the analysis finds.
“Mandates in the four sectors together can bring forward tipping points in heating, light and heavy road transport by two, three or four years, and in a few cases, by over eight years,” the report authors write.
‘Mature Governance’
During the launch webinar, Lenten was asked how the public should respond when leaders assert the merit of “technology-open or -neutral” policies. “Of course, neoliberals are arguing to not intervene with an industrial strategy, but they’re the same people that have got us into this mess,” he responded. “So frankly, I’m going to be blunt and say, ‘Why would I listen to them? I need to listen to the data and follow the evidence’.”
That conclusion calls for “a maturity of governance to ensure that the law is deployed in favour of the public good, and not against it,” he added.
Co-panelist Christiana Figueres, a former UN climate secretary and architect of the 2015 Paris agreement, agreed that “it is time for governments to take the training wheels off and mandate decarbonization, which means very clear targets and timelines for the decarbonization of the economy, sector by sector.” If governments don’t take that step, “they are not only underestimating what the innovation capacity of the global economy is, but they’re actually holding it back.”
