Should the mammoth live again? Why bringing back the extinct mammoth COULD keep the Arctic frozen

The weren’t just big, they were mammoth! With their thick shaggy fur, and long, curved tusks, woolly mammoths stood at 3 metres tall and weighed up to 7,000 kg.

When did woolly mammoths go extinct?

The last woolly mammoths went extinct around the same time that the Egyptians were building their pyramids. Parts of Siberia are littered with their remains. Teeth, tusks and sometimes even entire frozen carcasses are being pulled from the ground as the world warms and the permafrost melts. This is providing the starting material for those who wish to bring it back. 

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Why do scientists want to bring back the mammoths?

In its heyday, during the last Ice Age, the woolly mammoth played a vital role in its Arctic steppe ecosystem. As a keystone species, it sculpted its own ecosystem, and created opportunities for other species to thrive. Mammoths trampled saplings, ate grass and other plants, and fertilised the ground with their nutrient-rich dung. This provided habitat and resources for many other species, including invertebrates, birds and mammals.

What would happen if the mammoths were brought back?

Climate change and hunting caused their numbers to dwindle. Then, when they disappeared, so did the ecological services they provided. Biodiversity dwindled and the lush mammoth steppe was replaced by species-poor tundra. De-extinction advocates argue that if the animals could be returned to Siberia, their presence could help to recreate the Arctic steppe, in all of its former biodiverse glory. 

And that’s not all. Today, the Arctic permafrost contains the remains of that rich, fertile Ice Age ecosystem. An estimated 1,500 gigatons of carbon is locked up in the icy ground.  That’s twice as much as in the atmosphere. As the world warms, the far north is thawing, and little by little the carbon is being released as gas. This could accelerate climate change, but it’s not inevitable. 

Some think that mammoths could help to keep the Arctic cold. Studies show that when big grazers routinely trample the snow, they expose the surface of the soil to cold air, which helps to keep the ground frozen.

Research from biologist Sergey Zimov, from Siberia’s Northeast Science Station , indicates that soil temperatures in areas where big animals graze are, on average, several degrees colder than areas where grazers are absent. Return mammoths to the far north and they could help to keep the potentially dangerous carbon frozen away. 

There is certainly space for them. Zimov has created a 160km² nature reserve, called Pleistocene Park, full of Ice Age animals including bison and musk oxen. Should they be de-extincted, he would be happy to give the woolly mammoths a home there. 

• Mark Carwardine: de-extinction is not the solution to the extinction crisis

Whether or not the mammoths deliver on the promises that are made of them remains to be seen. The long-term goal of all of the current de-extinction projects is to return the animals to the wild, but no one knows for sure how these animals will fit in.

They could deliver the proposed biodiversity benefits, but they could also create problems. They might outcompete native species, for example, or be so successful that they have to be culled.

• Woolly mammoth vs elephant: What's the difference between these two giants?

Mammoths could help to keep the Arctic frozen, but with a lengthy gestation period and then 15 years to reach sexual maturity, the numbers required won’t be available any time soon.  There’s also no knowing if a de-extinct woolly mammoth, born to an Asian elephant, will know how to behave like a mammoth. Just like elephants, mammoths were social creatures that lived in complex groups and learned from one another.

So, are plans to bring back the mammoth a brilliant idea or woolly thinking? Only time will tell.

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