Three Years. Are You Listening, Justin? Three Years.

Three years. That's unless you're listening to the pessimists and then we're already well and truly screwed.

Three years. That's how long former UN Climate Chief Christiana Figueres says we have to take serious action if we're to avoid dangerous levels of climate change.

You wouldn't know it from anything you'll hear in our provincial legislatures or in our Parliament, certainly not from the Tories or the NDP or Justin's Liberal government, but we're getting perilously close to the wire or cliff edge or whatever your preferred metaphor.

Avoiding dangerous levels of climate change is still just about possible, but will require unprecedented effort and coordination from governments, businesses, citizens and scientists in the next three years, a group of prominent experts has warned.

The authors, including former UN climate chief Christiana Figueres and Hans Joachim Schellnhuber of the Intergovernmental Panel on Climate Change, argue that the next three years will be crucial. They calculate that if emissions can be brought permanently lower by 2020 then the temperature thresholds leading to runaway irreversible climate change will not be breached.

Schellnhuber, director of the Potsdam Institute for Climate Impact Research, added: “The maths is brutally clear: while the world can’t be healed within the next few years, it may be fatally wounded by negligence [before] 2020.”

Scientists have been warning that time is fast running out to stave off the worst effects of warming, and some milestones may have slipped out of reach. In the Paris agreement, governments pledged an “aspirational” goal of holding warming to no more than 1.5C, a level which it is hoped will spare most of the world’s lowest-lying islands from inundation. But a growing body of research has suggested this is fast becoming impossible.

Paris’s less stringent, but firmer, goal of preventing warming from exceeding 2C above pre-industrial levels is also in doubt.

Recall it was Schellnhuber who injected a bit of sobriety in the giddiness of the Paris climate summit in 2015 when he warned that the only possibility of not triggering natural feedbacks or runaway global warming demanded the "induced implosion" of the global fossil energy industry. He was saying that we have to shut this business down and fast. Apparently our then newly minted prime minister may not have stayed for that part of the Paris summit because he obviously didn't get that message. He's gone on to facilitate the rapid expansion of bitumen extraction and export complete with new pipelines, armadas of supertankers and even Corexit to bury the evidence when catastrophe occurs.

Our political caste, the current prime minister and his government included, demonstrate a rejection of these warnings. Decarbonizing our economy and our society isn't a matter of flipping a switch. Even if we committed to it today it would take years of planning, preparation and implementation. It's a truly Herculean task and we're nowhere near even beginning. The longer we pretend we're still in the 80s the further behind we get, the greater our challenge will be if we finally decide to act. The longer we wait the less likely it will become that we will change as we come to see that change as an insurmountable burden instead of an opportunity.

And the band played on.