The U.K. government may be mired in Brexit-related political chaos, but in at least one area, Westminster can claim some success: It’s proved that the right mix of government policies can dramatically reduce energy-related carbon dioxide or CO2 emissions, according to the International Energy Agency.
The country has had “major transformations” in energy policy since 2012, when the Paris-based agency last published a report on the U.K., it noted. And those transformations have successfully done what they were meant to do; they’ve pushed the country towards lower emissions.
“The United Kingdom has shown real results in terms of boosting investment in renewables, reducing emissions and maintaining energy security,” Dr. Fatih Birol, the IEA’s executive director, said in a release. “It now faces the challenge of continuing its transition while ensuring the resilience of its energy system.”
Mixing it up
That reduction is largely due to renewable energy taking over a greater share of the total energy mix. By 2017, “low-carbon” energy made up more than 50% of the electricity mix in the U.K., the IEA said. That was possible because of two particularly notable shifts, notably a dramatic reduction in the use of coal, and an increase in the use of wind power.
In 2017, the last year for which IEA used data, wind power rose to 15% of the total electricity mix from just 3% in 2010, and the use of coal declined to 7% of the mix, down from 29% in 2010.
In fact, the U.K. has recently hit a landmark: on June 4, the country ended an 18-day run of not using coal power at all—a new record, according to Britain’s Electricity System Operator, which tracks coal use. The country has said it will phase out all continuous use of coal for electricity generation by 2025.
This shifting balance—more renewable or low-carbon energy, less coal—resulted in greenhouse gas emissions falling by 35% from 1990 levels, and total greenhouse gases are down by 40%, “reaching some of the lowest recorded levels since 1888,” the agency said. (Yes, 1888.)
Government intervention
Another result: power and heat used to be the largest energy-related source of CO2 emissions in the U.K., but as those have declined, transport, at 34% of the emissions, has become the largest source.
How was this done? With government intervention—including a wide range of reforms to the country’s electricity market and through nationwide initiatives including the Industrial Strategy and Clean Growth Strategies, which set firmer emissions standards, encouraged investment in renewable energy, and implemented auctions to make renewable energy more competitive and affordable.
However, energy-related emissions make up only one part of total emissions. There, the U.K. has has also made some ambitious pledges: in May, the government Committee on Climate Change said it was possible for the country to reach “net-zero” emissions by 2050, as opposed to the previous target of reducing emissions by 80% by 2050. However, it said a wide range of tools would be necessary to get there, from redirecting significant land away from agriculture, to pushing for electrification of cars, to Britons eating less meat.
Lest we forget, big transitions do come with big price tags. According to the Financial Times, in a letter sent last week, U.K. Chancellor Philip Hammond warned outgoing Prime Minister Theresa May of the potential cost of the net-zero plan: 1 trillion pounds, or some $1.3 trillion.
More must-read stories from Fortune:
—‘Oil’ and ‘gas’ are out: How energy firms are rebranding for the climate change era
—How viable are AOC’s Green New Deal energy proposals? Just ask Europe
—Oil prices are being hit by the perfect storm–and laughing it off
—The Occidental-Anadarko petroleum merger’s crude truth about oil prices
—Listen to our new audio briefing, Fortune 500 Daily
Follow Fortune on Flipboard to stay up-to-date on the latest news and analysis.