As the world gets hotter, could helping trees migrate northwards protect them?

With the climate changing, many species are marching towards cooler climes - but trees are being outpaced. Some ecologists say assisted movement is the answer

At the top of an ancient oak at Knepp estate in West Sussex, a white stork has made a scruffy nest. The birds made headlines in 2020 when, after an absence of centuries in the UK, the first chick hatched. Alongside bison, beavers and white-tailed eagles, the storks are one of many species reintroduced to Britain in recent decades in an effort to restore animals to ecosystems where they had been wiped out. The oak tree, by contrast, has been here continuously for 12,000 years.

But ecologist Charlie Gardner is worried one of them may not have a future here - and it's the oak. By 2050, London's weather could resemble that of Barcelona, with long stretches of summer drought. These ancient trees were not designed to thrive in such conditions. More and more individual trees will die and reproductive success will fall," says Gardner. Around the world, millions of creatures facing unprecedented temperatures and habitat loss are on the move. The climate crisis is causing a vast array of species - from algae to butterflies, woodlice to birds - to shift northwards. Species are travelling north at a median rate of 17km a decade, according to 2011 research. That average equates to 20cm an hour - two to three times faster than previous estimates.