The effects of climate change and climate variability on forest ecosystems are evident around the world and further impacts are unavoidable, at least in the short to medium term. The potential impacts vary across regions, with some forest types more vulnerable than others; they include both increased and decreased plant growth, an increased frequency and intensity of fire and disease, and an increase in the severity of extreme weather events such as droughts, rainstorms and wind. In some cases, climate change is impairing the ability of forests to deliver critical wood and non-wood products and environmental services, such as watershed protection, to the detriment of the livelihoods of forest dwellers, forest-dependent communities and others who benefit from forests.

Meeting the challenges posed by climate change requires adjustments to forest strategies and to forest management plans and practices. Delays in taking action will increase the cost and difficulty of making those adjustments.

Adaptation and mitigation in forestry

Adaptation and mitigation are the two main responses to climate change. They are two sides of the same coin: mitigation addresses the causes of climate change and adaptation addresses its impacts.

In the forest sector, adaptation encompasses changes in management practices designed to decrease the vulnerability of forests to climate change and interventions intended to reduce the vulnerability of people to climate change.

Mitigation strategies in the forest sector can be grouped into four main categories: reducing emissions from deforestation; reducing emissions from forest degradation; enhancing forest carbon sinks; and product substitution. Substitution comprises the use of wood instead of fossil fuels for energy and the use of wood fibre in place of materials such as cement, steel and aluminium, the production of which involve the emission of large quantities of greenhouse gases.

Climate-change mitigation measures, including in forests, are urgently needed to help reduce human-induced interference with the climate system, but such measures will only begin to have an effect on global mean surface temperatures decades from now. For this reason, adaptation measures in forests to secure the continued delivery of forest goods and environmental services will be required for many years to come.