Limiting global warming to 1.5°C impossible without retiring or replacing all fossil fuel-burning infrastructure
To limit warming to no more than 2°C, it will be necessary to reach net-zero emissions by mid-century, says an international research team
Unless existing or planned fossil fuel-burning infrastructure such as power plants and vehicles are not retired early or replaced, countries will fail to meet the 1.5 degree Celsius climate-stabilizing goal set out by the Paris Agreement, says an international team of researchers. The implications of the study are striking and state that to achieve the objective of limiting warming to no higher than 2 degrees Celsius, it would be necessary to reach net-zero emissions by mid-century. This, according to the research team, cannot be achieved unless countries get rid of the long-lasting power plants, boilers, furnaces and vehicles before the end of their useful life and replace them with non-emitting energy technologies.
The Paris Agreement aims at keeping the global average temperature to well below 2°C above pre-industrial levels, with an ambition of limiting warming to 1.5°C.
“Countries can implement policies to both prevent commissioning of new assets and encourage early retirement of existing assets. Such policies might come in a range of different shapes and sizes, from strict prohibitions, removal of subsidies for fossil fuels, carbon taxes or prices, and subsidies for non-emitting energy technologies, among others,” Dr. Steven J. Davis, study’s co-author and associate professor of Earth system science at the University of California, Irvine, told MEA Worldwide (MEAWW).
The latest study is part of an ongoing collaboration between Dr. Davis and Dr. Ken Caldeira from Carnegie Institution for Science, Stanford.
“Non-emitting technologies are increasingly affordable, and may not be deployed as often as they could, not because they cost more, but because they are less familiar to customers. For example, some studies in the US have shown that the cost of building new solar power is, in some cases, less than continuing to operate existing coal power plants. This suggests that economic development need not be undermined by immediately moving away from fossil fuels,” Dr. Davis told MEAWW.
The research team found that if existing infrastructure operates as usual, it would emit about 658 gigatonnes of carbon dioxide during its operational lifetime. More than half of these emissions are projected to come from the electricity sector and infrastructure, with China producing the largest share (41%), followed by the US (9%) and Europe (7%). The ‘committed’ carbon dioxide emissions would jeopardize climate goals, says the study, adding that if built, power plants that are being planned, permitted or under construction, would emit an additional 188 gigatons of carbon dioxide, approximately.
“Net anthropogenic carbon dioxide (CO2) emissions must approach zero by mid-century (2050) to stabilize global mean temperature at the levels targeted by international efforts. Yet the continued expansion of fossil-fuel energy infrastructure implies already ‘committed’ future carbon dioxide emissions. We estimate that, if operated as historically, existing infrastructure would emit about 658 gigatonnes (Gt) of carbon dioxide (ranging from 226 to 1,479 Gt carbon dioxide depending on assumed lifetimes and utilization rates). If built, proposed power plants (planned, permitted or under construction) would emit approximately an additional 188 (range 37–427) Gt carbon dioxide,” the paper says.
The number of fossil fuel-burning power plants and vehicles in the world has increased dramatically in the past decade, spurred by rapid economic and industrial development in places such as China and India, say the researchers. Meanwhile, they add, the average age of infrastructure in developed countries has decreased.
According to the study, future emissions from existing energy infrastructure would take up the entire carbon budget needed to limit mean warming to 1.5°C and close to two-thirds of the budget to keep warming to under 2°C over the next three decades. Although the pace of growth of fossil fuel-burning infrastructure has slowed in recent years, a significant amount of new electricity-generating capacity has been proposed globally, and some of it is already under construction. “If this prospective infrastructure is built, the total future emissions take up three-quarters of the budget to constrain warming to below 2°C,” the paper says. The results conclude that there is no room for new carbon-dioxide emitting infrastructure under international climate goals.
The researchers used detailed data sets of existing fossil fuel-burning infrastructure in 2018 to estimate ‘committed’ carbon dioxide emissions. They assumed that power plants and industrial boilers would operate for about 40 years and that light-duty vehicles would be on the road for 15 years, with some regional variation in fuel economy and annual miles traveled.
The researchers also tested different lifetime assumptions to assess how early carbon dioxide-emitting infrastructure might need to be retired to meet international climate goals. For example, a 1.5°C boost in mean temperature might still be avoided if current power plants were shuttered after 25, rather than 40 years of operation, says the findings. The researchers say if countries are not able to retire existing fossil fuel-burning power plants and industrial equipment early, they can look at feasibly retrofitting them with carbon capture and storage technologies.
The study was published on July 1 in the journal Nature.