What On Earth

Why old-growth forests are an ally in fighting climate change

The fate of old-growth trees on the West Coast are once again the subject of blockades and hundreds of arrests. But this time, climate change is a much bigger part of the discussion, from the forests' carbon storage ability to resiliency against fire and other extreme weather.

From storing carbon to creating rain, old-growth forests matter more than ever, scientists say

Protester Diana Mongeau sits at the foot of an ancient yellow cedar in the Fairy Creek watershed. (Kieran Oudshoorn/CBC)

Deadly heat and fires have brought climate change home to Canada this week. But as some forests burn, others are storing huge amounts of carbon and working to combat weather extremes.

These are the ancient ecosystems that have stood long before humans raised the planet's temperature: highly prized — and highly contested — old-growth forests. They're at the centre of protests near a place called Fairy Creek on Vancouver Island, where more than 300 people have been arrested trying to protect them from logging

Battles over old growth are not new in B.C. The Nuu-chah-nulth and Haida First Nations led the way with blockades in the 1980s before the 1993 Clayoquot Sound protests gained international attention, and led to changes in logging practices there

This time around, however, there is a lot more scientific understanding of how old forests help fight climate change.

Not only do old-growth forests store vast amounts of carbon and provide oxygen, they cool the earth by creating shade and releasing water. And because of centuries of growth and high biodiversity, they're more equipped to withstand fires and other climate impacts.

This week, CBC Radio's What On Earth explores the climate benefits of old-growth forests.

Guest host Lisa Johnson talks to:

  • Dominick DellaSala, chief scientist at Wild Heritage, a project of the non-profit Earth Island Institute in California, about forest carbon, fire intensity, and old-growth resilience.
  • Werner Kurz, senior research scientist with the Canadian Forest Service for Natural Resources Canada, about the complexity of carbon accounting, and what's known about the role of old forests.
  • Salt Spring Island resident Sally Douglas, who shares her experience with an ancient "grandmother tree" as well as her surprise that B.C. still logs old-growth forests.
  • Dean Baigent-Mercer, a forest campaigner with the environmental group Forest & Bird in New Zealand, who was involved in that country's successful effort to end the logging of native forests on public lands.