What happens to the world if forests stop absorbing carbon? Ask Finland

A birch defoliated by autumnal moths (Epirrita autumnata) in Tanafjord, Norway, near the Finnish border. The warming Arctic climate is helping species that damage trees such as the moth and bark beetle. Photograph: Jorma Hevonkoski/The Guardian

Tiina Sanila-Aikio cannot remember a summer this warm. The months of midnight sun around Inari, in Finnish Lapland, have been hot and dry. Conifer needles on the branch-tips are orange when they should be a deep green. The moss on the forest floor, usually swollen with water, has withered.

“I have spoken with many old reindeer herders who have never experienced the heat that we’ve had this summer. The sun keeps shining and it never rains,” says Sanila-Aikio, former president of the Finnish Sami parliament.