Climate change threatens rare temperate rainforests

Up to two-thirds of the world’s temperate rainforests could fall victim to climate change by the year 2100 according to a new study.

In the first-ever worldwide assessment of the impacts of global overheating on these rare ecosystems, scientists used maps of tree cover, forest condition, and climate data to assess how many of the world’s temperate rainforests have already been impacted by human activity and how climate change would push some regions to the brink.

If we work hard to slow climate change it is not too late to save the world’s temperate rainforests.

Dr Ben Silver, School of Earth and Environment

The results of their study, which are published today (Tuesday 12 November) in the journal Earth’s Future, show that under the most pessimistic scenario, 68% of the world’s temperate rainforest, and in some regions 90%, would be lost over the next few decades.

Under current commitments to reduce fossil fuel emissions, 23% of the world’s temperate rainforests will be lost. However, rapid action to halt fossil fuel emissions would reduce this loss to 9%, highlighting the urgent need to avert climate change.

Temperate rainforests are restricted to areas with cool and moist climates. Countries which have temperate rainforests include Canada, USA, Chile, Japan, Australia, New Zealand and the UK.

Despite covering less than 1% of the Earth's land surface, they are recognized for their global ecological importance and carbon storage properties with intact temperate rainforests having higher carbon density than forests in other latitudes.

Dr Ben Silver, a Research Fellow from Leeds’ School of Earth and Environment led the study. He said: “Unmitigated climate change is a disaster for temperate rainforest in the UK and globally, as they cannot survive the kinds of high summer temperatures which we are starting to observe more regularly and are only predicted to worsen in future climate change simulations.

“Our study also shows that if we work hard to slow climate change it is not too late to save the world’s temperate rainforests.

“We hope our study will support the conservation of temperate rainforests by identifying those areas that are the least or the most vulnerable to climate change, and where there is potential to restore forest.”

Britain’s rainforests

In the UK temperate rainforests are found along the western seaboard, including the West coast of Scotland, North and West Wales, Devon, Cornwall, Cumbria and parts of Northern Ireland.

The Woodland Trust, which recognises temperate rainforests as a key conservation and restoration priority, describes them as one of the most biodiverse habitats, with the high humidity and low-temperature range creating the perfect conditions for moisture-loving lichens and bryophytes (mosses and liverworts).

Temperate rainforests now cover less than 1% of land in Great Britain and last year governments in Scotland and England announced plans to restore them.

The study concludes that the UK has more potential for restoration than anywhere else in the world, as it hosts a quarter of the world’s unforested temperate rainforest climate zone. The study also found that UK rainforests are resilient to low and medium amounts of future warming.

Professor Dominick Spracklen, a co-author of the study said: “The UK could and should be a global leader in restoration of temperate rainforests. New funding and bold action by large landowners are urgently needed to help deliver government targets for temperate rainforest restoration.”

Dr Dominick A. DellaSala, Chief Scientist of the US group Wild Heritage, and a global authority on temperate rainforests, added: “All the world’s rainforests are the ‘lungs of the planet’ that must be protected and restored as natural climate solutions to avoid the worst of global overheating. Temperate rainforests need to take their place alongside tropical rainforests and the boreal forests of the north as strategically vital to a safe climate.”