The British Isles are seen on a cloud-free day in a satellite image distributed by Dundee University. (Reuters)

LONDON — With only a few months before a major election, it can be tough to get politicians from opposing parties to agree on the color of the sky, much less the future of the planet.

That would seem especially true in the rough-and-tumble world of British politics, where the two main candidates for prime minister in the upcoming May election — incumbent David Cameron and challenger Ed Miliband — often prefer insulting each other to finding common ground. Cameron has called Miliband “a muppet” and “a waste of space.” Miliband has replied that Cameron is “dodgy” and “a dunce.”

But there’s at least one major issue on which the bitter competitors can agree: climate change.

Republicans and Democrats may still be jousting over whether human behavior is causing the planet to warm and, if so, whether anything should be done about it. But in Britain there’s no debate.

The consensus is so strong that Cameron and Miliband, along with Liberal Democrat leader Nick Clegg, have taken the extraordinary step during a heated campaign of signing a joint statement committing to fight “one of the most serious threats facing the world today.”

The statement, released early Saturday and brokered by the environmental think tank Green Alliance, binds the rivals to three specific pledges that would be inconceivable areas of agreement in American politics:

  • To seek a fair, strong, legally binding global climate deal which limits temperature rises to below 2°C.
  • To work together, across party lines, to agree on carbon budgets in accordance with the Climate Change Act.
  • To accelerate the transition to a competitive, energy efficient, low carbon economy and to end the use of unabated coal for power generation.

The statement also describes action on climate change as “an opportunity for the UK to grow a stronger economy, which is more efficient and more resilient to the risks ahead.”

Such rhetoric would be anathema to most congressional Republicans, who have blocked President Obama’s repeated efforts to pass climate change legislation on the grounds that it could hurt business.

But for Cameron, a conservative who champions free enterprise and lower taxes, the battle against climate change is one he’s repeatedly embraced. He even dog-sledded across a shrinking Norwegian glacier and attached a wind turbine to his house to showcase his concern.

By signing a joint pledge with Miliband, Cameron may be trying to neutralize what could otherwise be a line of attack for the Labor leader in what remains a too-close-to-call campaign. Despite Cameron’s rhetorical support for the climate change cause, he’s been criticized by environmentalists for falling short of what he had once promised would be the “greenest” government in British history.

In an op-ed published by the Independent in December, Miliband accused Cameron of “dither and denial” on environmental issues, saying the prime minister deprioritized them when they became less “fashionable.”

In the face of voter anger over rising energy bills, Cameron was even quoted telling aides to “get rid of all the green crap.” Downing Street disputed the language, though not the sentiment.

Climate change does not rank high on the list of British voter concerns, with the economy, health care and immigration all taking featured billing. But action on climate change is broadly backed among the British public, and unlike in the United States, few dispute the science.

By signing on to the same pledge as Miliband, Cameron may be trying to get back into voters’ green graces, with a laurel from perhaps the world’s best-known environmentalist to show for it.

“The agreement represents inspiring leadership and true statesmanship by all three men,” said Nobel Peace Prize winner and former U.S. vice president Al Gore in a statement. “The political courage it represents on all sides is exactly what our world most needs in order to solve the climate crisis.”