A rare, hole-some agreement 

With science in the unfamiliar role of trumping exploitation on the continent, more Antarctic research led to an alarming discovery: Manmade chemicals, notably chlorofluorocarbons (CFC's) used as refrigerants and propellants, were eating holes in the stratospheric ozone layer that protects the Earth from the sun's more harmful rays.

An expanding ozone "hole" over the South Pole, and a smaller one in the Arctic, threatened to impact plant and animal life by allowing ultraviolet solar radiation to reach the earth. Three scientists who were key to connecting the dots – Sherwood Rowland, Mario Molina and Paul Crutzen – began studying the effects of CFC's in 1973, and later shared the 1995 Nobel Prize in Chemistry for their work.

Concern grew throughout the 1980's as more research confirmed that the ozone holes were growing, and the ozone layer over temperate parts of the planet was thinning. Scientists, environmental advocates and industry all played their familiar roles, sounding the alarm, or drawing heavily on the doubt and denial playbooks.

But three world leaders defied assumptions and stereotypes, playing key roles in forging a global agreement to protect the ozone layer: Ronald Reagan, whose government normally fought environmental regulation; his conservative soulmate, UK Prime Minister Margaret Thatcher; and Canadian PM Brian Mulroney, who lobbied to become the host nation for a crucial meeting.

In 1987, the Montreal Protocol was signed, phasing out CFC's and other ozone depleting chemicals. It's now ratified by 197 nations and the EU. By the mid-2000's, scientists confirmed a gradual closing of the ozone holes, with a return to normal levels by 2100.

It's hard to imagine the contemporary conservative heirs of Reagan, Thatcher and Mulroney showing similar leadership. Trump's anti-regulatory rampage included a departure from the Paris climate accord; the UK's Brexit quagmire was partially inspired by disdain for European Union environmental policy; and Stephen Harper, the most recent Canadian conservative PM, directed a thorough purge of government environmental science.

But the urgent need for action on climate change, biodiversity, the nearly-unthinkable collection of plastic in our oceans, and other challenges may someday turn the corner for Tea Partiers and Brexiteers.

The Antarctic Treaty and the Montreal Protocol are real-life examples of how it can be done.