Countries are cheating their way to net zero by relying too much on forests

Countries are taking shortcuts to net-zero emissions by including forests and other “passive” carbon sinks in their climate plans, a tactic that thwarts global efforts to stop climate change. leading researchers have warned.

Relying on natural carbon sinks to absorb continued carbon emissions from human activities will keep the world warmer. This comes from the researchers who first developed the science behind net zero emissions and today launched a highly unusual intervention accusing nations and companies of abusing the concept.

“This paper asks people to clarify what net zero originally meant,” Miles Allen of the University of Oxford said at a press conference on November 14.

Natural sinks such as forests and peat bogs play an important role in Earth’s natural carbon cycle by absorbing some of the carbon from the atmosphere. However, we cannot rely on existing sinks to offset ongoing greenhouse gas emissions.

If used in this way, global atmospheric carbon dioxide concentrations would remain stable even when we reach “net zero,” and warming would continue for centuries due to the way the oceans absorb heat. Allen warned. “Even if we think we’re on the path to 1.5 degrees Celsius, we could end up with a temperature rise of well over 2 degrees Celsius,” he says. “This ambiguity could effectively destroy the goals of the Paris Agreement.”

To halt global temperature rise, we need to reduce emissions to net zero, without relying on passive absorption by land and oceans. This allows existing natural sinks to continue absorbing excess CO2, reducing the concentration of the gas in the atmosphere and offsetting ongoing warming from the deep ocean.

However, many countries already count passive land sinks such as forests as greenhouse gas removals in their national carbon accounts. Some countries, such as Bhutan, Gabon, and Suriname, have even declared themselves net-zero already, thanks to their existing vast forest cover.

Some companies are setting long-term net-zero targets based on this approach. Russia, for example, has pledged to reach net-zero emissions by 2060, but its plans rely heavily on using existing forests to absorb ongoing carbon emissions.

“Maybe some countries will deliberately use this in a naughty way,” said Glenn Peters of the CICERO International Climate Research Center in Oslo, Norway. “This problem will be even more problematic in countries with a large proportion of total land area under forest.”

The researchers fear this problem will become more serious as carbon markets develop and pressure on countries to decarbonize increases. “As the value of carbon increases, there will be more pressure to define anything that can be removed as a negative emission, potentially to be able to sell it on the carbon offset market,” Allen said.

Countries and companies with net-zero targets will need to modify their approach to exclude passive carbon sequestration from their accounts, the researchers say.

Natural sinks count as carbon removal when they are added to existing ones, for example when new forests are planted or peat bogs are rewetted. However, this type of natural carbon sink is vulnerable to climate impacts such as wildfires, drought, and the spread of invasive species, and is unreliable for long-term sequestration.

This has not stopped countries from relying heavily on these natural sinks in their net-zero strategies. A 2022 study found that many countries, including the United States, France, Cambodia, and Costa Rica, plan to rely on forest carbon and other naturally occurring removals to offset ongoing emissions. It turns out. “Many national strategies ‘bet’ on increasing carbon sinks in forests and soils as a means of achieving long-term goals,” the study authors wrote.

Allen stressed that natural carbon sinks must be conserved but not relied on to balance ongoing emissions. Instead, he urges countries to aim for “geological net zero,” where long-term carbon sequestration in underground storage ensures that all ongoing carbon emissions are balanced.

“Countries need to recognize the need for geological net zero,” he said. “This means that if we are producing carbon dioxide from burning fossil fuels by mid-century, we will need to have a plan to put that carbon dioxide back into the ground.”

“Geological net zero seems like a sensible global goal for countries to aspire to,” says Harry Smith of the University of East Anglia in the UK. “This will help clarify many of the ambiguities that plague the current way countries consider land travel.”

But it could have knock-on effects on climate ambitions, he warns. “What does the new politics of geological net zero look like? If geological net zero drives climate strategy goals, how will this impact governments’ climate change ambitions?” Would you give it?”