This is the second chapter in The Road to COP26 series.
Growing worries about the speed and scale of climate change are prompting a look at technologies ranging from nuclear to sci-fi schemes like space mirrors. But there’s one system that’s been doing a pretty good job of pulling carbon from the atmosphere for the last 360 million years: trees.
That’s made forests a favored low-tech way of combating global warming — including by the European Union, which calls for planting 3 billion trees by 2030 as part of its effort to cut CO2 emissions by 55 percent by that year.
But it’s a risky gamble as those trees are in danger from some of the consequences of climate change, including increasing wildfires, droughts and pests. And trees that burn or die end up releasing their captured CO2 back into the atmosphere.
“European forests have been removing CO2 for many years,” said Peter Iversen, forests and climate expert at the European Environment Agency (EEA), but “we see a decline” in the last five years. “They are removing less than before.”
The bloc’s forests currently absorb about 10 percent of the EU’s CO2 emissions. But Iversen said that “some countries have been suffering from insect infestations, in particular bark beetles” and “that has cost them some forests, removals and even sometimes led to net emissions [increases].”
Those problems mean the EU’s tree-planting program “needs to be done properly,” Iversen said. “There [are] a lot of things to think about before planting trees,” including finding the right place and the right species adapted to the local ecosystem and considering the effects of climate change to ensure the trees stand for as long as possible.
But planting trees isn’t a panacea and should be part of a broader strategy linked to drastic emissions reductions, said Katia Prassoloff, customer sustainability and communications manager at Reforest’Action. Massive afforestation projects can also create tensions over whether land should be used for forests or farming.
Another question is whether EU countries will have the capacity to breed enough young trees.
“There was an extraordinary scenario at the last British election when every political party was promising to plant more trees, offset and reach net zero emissions … ignoring the fact that this would require a huge number of imported trees,” said Matthew Orman, executive director of the Sustainable Soils Alliance, a not-for-profit company based in the U.K.
Carbon credit questions
It’s not just governments planting trees. Many corporate carbon credit plans finance tree planting as a way of offsetting their emissions.
But such schemes “should only be used as a complement, to offset your unavoidable emissions,” said Prassoloff, whose company links local initiatives with businesses willing to buy carbon credits, but only after they have done their utmost to reduce their emissions.
She warned that “offsetting doesn’t mean erasing your impact,” adding that she encourages companies to avoid saying they’re carbon neutral because “it sends the wrong message unless you really have zero emissions.”
Planting trees is also not a miracle cure for emissions being pumped into the atmosphere today. It takes decades for a seedling to grow into a mature tree that absorbs about 30 kilograms of carbon a year.
“The element of time is often forgotten when talking about the carbon balance of forests,” said German Green MEP Anna Deparnay-Grunenberg, who has a background in environmental science and forest management. “Yes, in the end, forests will be carbon neutral, but not before 80 or 100 years, and we can’t wait that much time.”
And once planted, trees face risks from fires — something that’s devastated forests from Greece to Scandinavia, Siberia and western North America this summer. The latest report by the U.N.’s Intergovernmental Panel on Climate Change finds “more frequent occurrence of extreme climate events, such as heatwaves” are likely, with a prediction that fire weather conditions will increase in much of Europe.
“If fires’ frequency and intensity increase it will be negative for the capacity of forests [to absorb CO2] because they won’t have the time to regrow,” Iversen warned.
In the United States, some carbon removal programs, where landowners are incentivized to manage their land to maximize carbon storage, have already gone up in flames — including ones supported by BP and Microsoft to offset their emissions.
Prassoloff said that so far none of the projects Reforest’Action manages in France or in Brazil have been hit by fires but conceded that resilience to climate change and fires is a risk that the company is increasingly considering when selecting projects to fund.
One way of insuring carbon removal projects against the impact of fires is so-called buffer accounts.
“A certain quantity of the carbon credits that are generated by each project is kept on a specific account and cannot be sold to companies for offsetting,” Prassoloff said. “It is used in case the forest project is destroyed … The idea is to take into account the risk of the sequestered carbon being re-emitted into the atmosphere in case there is a fire or another type of hazard that can damage the forest.”
How forests are managed can also increase or decrease their absorption capacity. The European Commission’s Forest Strategy has set off a political fight over how to balance the use of forests to absorb carbon and protect biodiversity with economic interests such as logging and energy use.
Some practices are bad both for the climate and for trees’ capacity to absorb CO2, like clear-cutting large areas, said Deparnay-Grunenberg.
“Forest soil is like a sponge,” she said. It absorbs water but also CO2, and helps prevent drought and erosion. “But if we clear cut an area, the soil gets hard and cannot retain water anymore.”
“We don’t want to not touch forests at all anymore, but we need truly sustainable forest management,” she said.
Source: Politico
