Deforestation and forest degradation are both a cause and a result of climate change. Plants absorb carbon dioxide and use it to grow, but when they decay or burn the carbon dioxide is released again. Decaying plants also produce methane, a greenhouse gas more potent than carbon dioxide.
So deforestation and forest degradation are doubly damaging, because
greenhouse gasses are released (e.g. through forest fires, or using the
cut trees as firewood), while at the same time the number of carbon
dioxide absorbing trees are reduced. Thirty percent of the carbon
dioxide added to the atmosphere over the past 150 years is thought to
come from deforestation, but this is a small amount compared to what is
still stored in forests. The Canadian and Russian boreal forests alone
hold 40 percent of the world's carbon stocks.
How climate change is hurting forests
Changes
in temperature ranges and precipitation can harm forests. Droughts and
forest fires are expected to increase due to climate change. Forest
fires can be a normal part of forests - they clear dense brush and are
part of some species lifecycle. However, forests over stressed by human
activity and drought can also be devastated by them. There are already
indications that the Amazon is drying out, which could lead to a
dangerous feedback of fires and desertification.
Invasive
insect species may also damage forest health. Insects play a role in
boreal ecology - they decompose litter, supply food for birds and small
animals, and eliminate diseased trees. But insect attacks are likely to
increase in frequency and intensity as established forests succumb to
the physiological stress associated with warmer, drier conditions. As
the Arctic warms, some invasive insect species, which the colder
climate normally helps hold in check, are already increasing in
population.
Replanting and sustainable forestry
It's
worth noting that proper sustainable forestry practices do not cause a
net increase of carbon dioxide in the atmosphere because a new tree is
grown for every one cut down. By contrast, clear cutting and converting
forestland into to urban areas has a very high negative impact -
because the forest is destroyed and replaced with heat absorbing
pavement and buildings.
Obviously, re-forestation, sustainable
logging and protecting ancient forests are essential to not increase
the pace of climate change further - so long as these forests are not
destroyed later (by future logging, forest fires, etc.).
However,
to prevent dangerous human induced climate change, we need to address
the main cause - the burning of fossil fuels and the release of
industrial greenhouse gasses into the atmosphere.
Also see our
ancient forests campaign information.
Help
protect the world's ancient forests by buying only Forest Stewardship
Council (FSC) certified wood, and products with post-consumer recycled
content. You'll be saving vital habitat, and doing good by the climate
at the same time.