One way of curtailing climate change involves sequestering atmospheric carbon in plants and so the more trees there are around the planet, the better our chances of keeping global temperature rises under control in coming decades.
“The global forestry sector can provide a really substantial chunk of the mitigation needed to hit global climate targets,” stresses Justin Baker, associate professor of forest resource economics at North Carolina State University.
Yet Baker and his colleagues from several leading institutions caution in a study that the costs of protecting and planting trees as carbon sinks cost us increasingly more if we are to achieve a 10% target in total emissions reductions to restrict climate change to 1.5 degrees Celsius.
In fact, it could cost as much as $393 billion a year by 2055 to pay the owners of private forests to plant and protect enough trees to soak up CO2 from the air.
“The physical potential is there, but when we look at the economic costs, they are nonlinear,” Baker says. “That means that the more we reduce emissions — the more carbon we’re sequestering — we’re paying higher and higher costs for it.”
Baker and his colleagues set out to analyze the cost of preserving forests and planting new trees by help of a price model called the Global Timber Model, which estimates the costs of preserving trees in national parks in the United States and privately owned forests belonging to companies that harvest trees for pulp and paper products.
The researchers estimated that by 2055 it would cost $2 billion a year to prevent 0.6 gigatons of carbon dioxide from being released into the atmosphere. A sum of $393 billion would sequester 6 gigatons a year, or the equivalent of emissions from nearly 1.3 billion passenger vehicles driven for a whole year.
The key role is to be played by tropical forests in the Amazon, the Democratic Republic of Congo and Indonesia, among other countries, which will account for anywhere between 72% and 82% of total global mitigation from forestry in 2055.
Yet even in temperate regions, effective forest management can play a significant role, especially if extensive measures of reforestation and afforestation (introducing trees to areas that have not had any) are undertaken.
“Protecting, managing and restoring the world’s forests will be necessary for avoiding dangerous impacts of climate change, and have important co-benefits such as biodiversity conservation, ecosystem service enhancement and protection of livelihoods,” observes Kemen Austin, a senior policy analyst who is a lead author of the study.
