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In May 1845, seasoned polar explorer Sir John Franklin set out with two ships and 128 men, heading north from Britain as far as it was possible to go. He was searching for the Northwest Passage, a sea route from the Atlantic Ocean to the Pacific via the Arctic. It wasn’t his first attempt to find the route, and he had a good idea of what he could expect to find. His ships were comfortably heated, amply supplied and reinforced to resist the ice.
In July, the two ships were spotted by a whaler in Baffin Bay, an icy stretch of water between Baffin Island, in the north of Canada, and Greenland. That was the last time they would be seen. All 129 men died, and despite a number of attempts to find them, their fate remains largely a mystery today.
Franklin’s attempt is remembered for its disastrous end, but there had been many others, all unsuccessful until the 1900s. Then, Roald Amundsen sailed north in a converted herring boat. With a crew of just six and a boat just 20 metres long, his chances might have seemed slim, but Amundsen knew what he was doing. His boat was trapped in the ice, and it took him three years, but he made it.
Despite Amundsen’s success, it was clear that the route was far from an easy alternative to the long ocean voyages through the tropics. The journey through the Arctic was still long and perilous. It would be another forty years before someone managed to make the trip in a single year. The Northwest Passage did not look as if it would ever be a viable commercial route.
But something has happened to the Northwest Passage journey in the last two decades. The ice has been retreating and now people are making the journey in all sorts of different vessels, and in record time. Some are reporting that they see hardly any ice. It’s still far from being a regular route for commercial shipping, but it’s clear that the Arctic is changing.
I hadn’t appreciated how much the ice had retreated until I looked at a series of satellite images from NASA that showed the sea ice extent from 1979 until 2021 (check it out yourself, here). It’s clear from the video that the Arctic sea ice is changing, and changing fast. Sea ice that once stretched across the Arctic Ocean from Russia to Greenland is now retreating, leaving much more open ocean.
But it isn’t just the sea ice that is changing – it’s the whole of the Arctic. Since 1979, the region has been warming faster than the rest of the world. How much faster is debatable – I’ve found credible sources saying twice as fast, three times as fast and even four times as fast. The sources aren’t disagreeing, rather they all cover slightly different time periods and define the ‘Arctic’ differently. But all make it clear that Arctic warming is significantly higher than global averages.
To understand why the Arctic is changing, it helps to know a little basic physics. Dark objects absorb the energy from visible light and convert it into heat. The darker the object, the more light it absorbs and the more it heats up – that’s why on a sunny day, the road gets unbearably hot. White objects, including land and sea covered with ice, reflect light back without absorbing it. Because they don’t absorb light, they stay cool.
Places covered with ice and snow, like the Arctic, reflect most of the light that reaches them. That means that they heat up less in response to the energy they receive from the sun, compared to an ice-free area that received the same amount of light. This process works as long as the ice and snow lasts, but once it melts, it’s as if a switch flips. The more the Arctic warms, the more the ice and snow melt. The more the ice and snow melt, the more the dark land and sea is exposed. The more land and sea that is exposed, the more the Arctic warms. And the more the Arctic warms, the more the ice and snow melt… and so on and so on.
The Arctic is now caught in a dangerous feedback loop known as polar amplification. It’s happening in Antarctica as well, although so far only on the Antarctic Peninsula. And the warming is creating all sorts of problems.
Perhaps the most well-known impact is on the Arctic’s iconic species, the polar bear. These huge bears mainly hunt seals from the sea ice, and so the loss of sea ice threatens to starve them. Around the Arctic, there are 19 separate populations of polar bear, and a recent study found that most of these populations of polar bear are under threat from climate change. Even with our efforts to reduce emissions, some of the populations were likely to be wiped out within the next 80 years.
Another iconic Arctic species under threat is the reindeer, also known as caribou. In 2018, scientists reported that numbers of this species had more than halved over the last 20 years. Just as with the polar bears, warming is affecting their food supply. The lichen that they favour is now often out-competed by taller-growing grasses which are favoured by the warmer temperatures.
Plants in the Arctic are changing too, and there are winners and losers. The treeline – the upper limit on where trees can grow – is steadily moving north. This means more trees and less tundra – the vegetation of grasses, herbs, low shrubs and lichen which is typical of the high Arctic. That’s part of the problem facing reindeer, but it’s a problem for humans as well.
The tundra exists as a thin layer of vegetation and soil over a thick layer of frozen ground called permafrost. As the name implies, permafrost is frozen all the time – it’s not seasonal, or rather it wasn’t. Now, it’s melting, and up to 40% of it could be gone even if we keep warming to under 2 degrees Celsius.
The thawing permafrost is creating real problems for people who live in the Arctic. All of their infrastructure – buildings, roads and pipelines – sits on top of the permafrost. As it melts, the ground collapses. This can cause erosion and landslides, and can cause buildings to crack or collapse. Coastal communities are particularly vulnerable, because they are also affected by the reduction in sea ice, which leaves them more vulnerable to storms and sea level rise.
But there’s another impact of Arctic warming that’s received far too little attention. I didn’t know about it until I started to read about wetlands a couple of weeks back, and I admit that I was shocked. Because the warming of the Arctic has awakened a sleeping giant – a huge store of carbon which is now being released into the atmosphere.
Above the permafrost, the Arctic soil is mostly peat. I talked about peat two weeks ago, in my article about the role of wetlands in carbon storage. Basically, peat wetlands such as bogs are storing a huge amount of carbon – 600 gigatons of it, which is more than in all the world’s forests. And because that carbon is stored in peat, it’s not in the atmosphere and contributing to climate change.
But when the permafrost melts, that changes. The peat begins to break down. Some of the peat breaks down to form carbon dioxide. Even worse, because the ground is wet, which excludes oxygen, some of that breakdown happens in the absence of oxygen. Without oxygen, the peat breaks down to form methane, which is a much more potent greenhouse gas. The thawing of permafrost creates another dangerous feedback loop. The more the climate warms, the more the permafrost melts. The more the permafrost melts, the more carbon dioxide and methane is released. The more carbon dioxide and methane that is released, the more the climate warms. And the more the climate warms, the more the permafrost melts… Like an avalanche starting with a small amount of snow, Arctic warming is accelerating at a frightening pace.
It's easy to forget about what’s happening in the Arctic. We don’t hear much about, and few of us will ever see it. But it’s important. Because the thawing of the Arctic is accelerating climate change, that affects us all.
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I kind of hate to "like" this post...
Your title is so appropriate. This is scary stuff.
That is intense. I'm curious: does methane form at the same rate as CO2?