Historical analysis finds no precedent for the rate of coal and gas power decline needed to limit climate change to 1.5°C
From: Cell Press
October 22, 2021 – Limiting climate
change to the 1.5°C target set by the Paris Climate Agreement will likely
require coal and gas power use to decline at rates that are unprecedented for
any large country, an analysis of decadal episodes of fossil fuel decline in
105 countries between 1960 and 2018 shows. Furthermore, the findings, published
October 22 in the journal One Earth, suggest that the most rapid
historical cases of fossil fuel decline occurred when oil was replaced by coal,
gas, or nuclear power in response to energy security threats of the 1970s and
the 1980s.
Decarbonizing the energy sector is a
particularly important strategy for reaching the goal of net-zero greenhouse
gas emissions by 2050, which is necessary in order to prevent global average
temperatures from climbing beyond 1.5°C this century. However, few studies have
investigated the historical precedent for such a sudden and sweeping transition
-- especially the decline of carbon-intensive technologies that must accompany
the widespread adoption of greener ones.
"This is the first study that
systematically analyzed historical cases of decline in fossil fuel use in
individual countries over the last 60 years and around the world," says
Jessica Jewell (@jessicadjewell), an associate professor in energy transitions
at Chalmers University in Sweden, a professor at the University of Bergen in
Norway, and the corresponding author of the study. "Prior studies
sometimes looked at the world as a whole but failed to find such cases, because
on the global level the use of fossil fuels has always grown over time."
"We also studied recent political
pledges to completely phase out coal power, which some 30 countries made as
part of the Powering Past Coal Alliance. We found that these pledges do not aim
for faster coal decline than what has occurred historically," adds Jewell.
"In other words, they plan for largely business as usual."
To explore whether any periods of
historical fossil fuel decline are similar to scenarios needed to achieve the
Paris target, Jewell and her colleagues, Vadim Vinichenko, a post-doctoral
researcher at Chalmers and Aleh Cherp, a professor at Central European
University in Austria and Lund University in Sweden, identified 147 episodes
within a sample of 105 countries between 1960 and 2018 in which coal, oil, or
natural gas use declined faster than 5% over a decade. Rapid decline in fossil
fuel use has been historically limited to small countries, such as Denmark, but
such cases are less relevant to climate scenarios, where decline should take
place in continental-size regions.
Jewell and colleagues focused the
investigation on cases with fast rates of fossil fuel decline in larger
countries, which indicate significant technological shifts or policy efforts,
and controlled for the size of the energy sector, the growth in electricity
demand, and the type of energy with which the declining fossil fuel was
substituted. They compared these cases of historical fossil fuel decline to
climate mitigation scenarios using a tool called "feasibility space,"
which identifies combinations of conditions that make a climate action feasible
in particular contexts.
"We were surprised to find that the
use of some fossil fuels, particularly oil, actually declined quite rapidly in
the 1970s and the 1980s in Western Europe and other industrialized countries
like Japan," says Jewell. "This is not the time period that is
typically associated with energy transitions, but we came to believe that some
important lessons can be drawn from there." Rapid decline of fossils
historically required advances in competing technologies, strong motivation to
change energy systems (such as to avoid energy security threats), and effective
government institutions to implement the required changes.
"We were less surprised, but still
somewhat impressed, by how fast the use of coal must decline in the future to
reach climate targets," she adds, noting that, of all the fossil fuels,
coal would need to decline the most rapidly to meet climate targets,
particularly in Asia and the OECD regions where coal use is concentrated.
About one-half of the IPCC
1.5°C-compatible scenarios envision coal decline in Asia faster than in any of
these cases. The remaining scenarios, as well as many scenarios for coal and
gas decline in other regions, only have precedents where oil was replaced by
coal, gas or nuclear power in response to energy security threats in smaller
electricity markets. Achieving the 1.5°C target requires finding mechanisms of
fossil fuel decline that extend far beyond historical experience or current
pledges.
The authors found that nearly all
scenarios for the decline of coal in Asia in line with Paris Agreement's goals
would be historically unprecedented or have rare precedents. Over half of
scenarios envisioned for coal decline in OECD countries and over half of
scenarios for cutting gas use in reforming economies, the Middle East, or
Africa would also be unprecedented or have rare precedents as well.
"This signals both an enormous
challenge of seeing through such rapid decline of fossil fuels and the need to
learn from historical lessons when rapid declines were achieved on the national
scale," says Jewell.
https://www.sciencedaily.com/releases/2021/10/211022123755.htm
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