More than 95% per cent certain. That’s what 800 of the world’s top scientists are expected to say tomorrow about their confidence that humans are causing climate change. They’re also more certain than ever about the serious negative impacts it will have on nature, on economies, and society (that means us, by the way).
To put it in perspective, they are as certain that global warming is a real, man-made threat as they are that cigarettes kill.
Twenty five years of work by the Intergovernmental Panel on Climate Change comes to this: greater and greater certainty around what they have been saying for decades now.
That’s not a criticism: it’s an indication of just how thorough the IPCC has been. Just counting the efforts for the IPCC’s Fifth Assessment Report, the process involved 800 authors citing more than 9,000 scientific publications. There were over 1000 expert reviewers from 55 countries, including representatives from 38 governments. The Summary for Policy Makers document will be approved – line by line – by 195 governments.
This isn’t just the most comprehensive review of climate change – it may well be the most comprehensive scientific review of any topic, ever.
In addition to clarity on the process of climate change, the science is also clear that the impacts will extend far beyond temperature rise. Sea levels are rising, faster than previously estimated. Precipitation patterns are beginning to change, and generally speaking, wet places will get wetter and dry places dryer. (Sympathies to my friends in Prince Rupert – and in western Australia.) Glaciers are shrinking, ice is retreating, and oceans are acidifying.
Believe it or not, this is not a doom and gloom message. It’s a call to action: the future is still ours to make. The IPCC lays out several scenarios showing how different emissions “pathways” could play out. Optimistically, if we cut emissions by about 10% per decade, we could limit temperature rise to less than 2 degrees Celcius above pre-industrial levels (the internationally recognized threshold we should avoid). On the other end of the spectrum, if we do nothing and continue on their current path, we are as likely as not to hit 4 degrees of warming by 2100. (If that doesn’t sound like much, some scientists have suggested a 4 degree rise might be incompatible with an organized global community).
So, how should we, as Canadians, respond?
For a start, it should spur a serious and urgent political discussion – at all levels – about how to ramp up our efforts. Let’s say it out loud: we’re on track to miss the federal government’s own 2020 emissions reduction target by 50 per cent. We need a National Energy Strategy that puts us on track to close that gap. The oil sands are projected to double within a decade. More cheery TV ads touting the benefits of new oil pipeline proposals seem to appear each day. Energy efficiency programs and retrofit funding has been cut or discontinued. All of this takes us further away from the future we know we need.
The good news is that we know what we need to do and how to do it. We’ve got positive examples on which to build, like BC’s carbon tax, Ontario phasing out coal, Quebec’s support for electric vehicles, and many others. We deserve rigorous and, yes, cross-the-aisle debate about how to deploy tools effectively. How to transition, over time, away from fossil fuels, not deepen our economic dependence on them. That is the conversation that will move us forward.
Science has brought us this far, has given us the certainty on which we must act. The future is now in our hands.