The Slims river in northern Canada gained infamy, not for its fishing or pristine waters, but for vanishing in a matter of four days in May 2016. This week we learned that it fell victim to “river piracy” – and climate change was almost certainly to blame.



The river – which stretched up to 150 meters at its widest points and averaged depths around three meters – lost its water source to another nearby river during a period of intense melting affecting one of Canada’s largest glaciers. As a result, the Slims was reduced to a trickle in less than a week.

We can now add river piracy to the growing list of unexpected, dramatic and tragic consequences of human-caused climate change. Although this is the first observed case of river piracy, it likely won’t be the last.

The melting of Yukon’s massive Kaskawulsh glacier – known to the local Southern Tutchone First Nation as Tänshī – caused the drainage gradient to tip in favour of the second river, redirecting the meltwater to the Gulf of Alaska, thousands of miles from its original destination.

The science says there’s a 99.5% chance that climate change caused this dramatic transformation of the landscape. The continuing warming trend that caused the glacier to thin so extremely means the change is likely irreversible.

Receding glacier causes immense Canadian river to vanish in four days Read more

Such a rapid transformation of the river alters more than just the physical geography and ecosystems of one of Canada’s most majestic and ecologically sensitive regions. It also affects local Indigenous communities.



Residents near Kluane Lake, which the Slims river used to feed, reported water level changes immediately after the river’s disappearance. The lake is now about three meters lower than normal, and is in jeopardy of being cut off from its own outflows — making traditional food for the Kluane people, such as trout and whitefish, much harder to find.

Climate change’s extreme impacts are obvious to communities throughout the north, from documented hunting season changes and wildlife migrations to rising coastlines and drunken forests, where trees now lean into rivers as permafrost melts and land gives way.

We’ve seen images of climate change shrinking the world’s glaciers before, which is worrying, if you consider that these glaciers are like bank accounts: they store snow and ice during cool, wet weather and release water when an area needs it most, during hot, dry summers or droughts.

When nature’s thresholds are passed, everything changes. Landscapes are radically transformed in the blink of an eye. In this case, river piracy is a dramatic reminder that the consequences of climate change are often unpredictable.

It’s also proof that climate change isn’t a problem of the future. It’s happening now. We’re seeing the increasing effects of climate change every day.

So, what to do about this dismal assessment?

We must transition our economies quickly and decisively away from fossil fuels to renewable energy, and governments must play leadership roles to make this happen.

We must move forward with a common understanding that we are embedded in the natural world, and what we do to our surroundings, we do to ourselves.

I was part of the wave of hope that ushered in Justin Trudeau as Canada’s prime minister in 2015. I applauded Canada’s commitments to the Paris agreement, especially our country’s push to limit the average global temperature increase to 1.5C.



But since Paris, Prime Minister Trudeau has approved two oil pipelines and one of Canada’s largest carbon dioxide-emitting liquefied natural gas (LNG) projects, virtually ensuring that Canada will not meet its own climate targets.



Stop swooning over Justin Trudeau. The man is a disaster for the planet | Bill McKibben Read more

As the new US president works to dismantle hard-won climate initiatives south of our border, a clear and effective approach to climate change in Canada is more important than ever.

Making deep reductions in carbon emissions can’t wait until 2050. Humans are the dominant force on the planet, and we’re causing unprecedented impacts. Human-caused climate change is making events like hurricanes, floods and droughts stronger and more frequent.

I believe there’s still hope. Nature has the ability to continue to shock us. If we pull back and give nature room to recover, it may surprise us.

So who are the pirates? In the case of the Slims, certainly not the second river, and certainly not nature. We are the pirates, and we’re robbing ourselves. If we don’t act on climate change now, we’re stealing the prospect of a clean and healthy planet from ourselves, our children and generations to come.