LONDON — Prime Minister Theresa May on Wednesday proposed legislation under which Britain would lower its net production of greenhouse gases to zero by 2050.
Such a move would make the U.K. the first of the world’s major economic powers to commit to ending its contribution to global warming.
The plan does not say how the nation would reach the emissions goal or what it would cost, and future governments could change course — in fact, the proposal appears to leave the door open for Britain to back away from the commitment if other countries do not follow its lead.
But May’s bill sets a new bar for measuring environmental progress by the world’s major industrial powers.
“It is imperative that other major economies follow suit,” the prime minister’s office said in a statement. “For that reason, the U.K. will conduct a further assessment within five years to confirm that other countries are taking similarly ambitious action, multiplying the effect of the U.K.’s lead and ensuring that our industries do not face unfair competition.”
The finance chief in her government, Philip Hammond, has privately warned the prime minister that her proposal could cost Britain about $1.2 trillion, according to British news reports, and climate change skeptics have said that even that estimate could be low. But the prime minister’s office said such dire predictions were wrong.