Preventing the world from blowing past the 1.5-degree-Celsius (2.7-degrees-Fahrenheit) threshold identified by the Paris climate agreement is unlikely if reducing emissions of carbon dioxide and other greenhouse gases is the only approach taken toward that goal. Hitting this target, aimed at allowing Earth and its inhabitants to avoid the worst effects of human-caused climate change, will almost certainly also require sucking greenhouse gases directly out of the atmosphere and somehow storing them.
In the United Kingdom, reaching net zero carbon emissions by 2050 is likely to require pulling an estimated 100 million tons of carbon dioxide out of the sky every year, reports Damian Carrington for the Guardian.
To that end, this week the U.K. announced the start of trials for five methods of removing planet-warming carbon dioxide from the atmosphere, according to a statement from U.K. Research and Innovation (UKRI).
“Reducing greenhouse gas emissions is a priority for the U.K., but it’s clear that alone that will not be enough to reduce CO2 and meet the U.K.’s net-zero climate target by 2050,” says Duncan Wingham, executive chair of the Natural Environment Research Council at UKRI, in the statement. “These projects will investigate how we can actively remove greenhouse gases from the atmosphere using innovative technologies at the scale required to protect our planet.”
The country’s new roughly $42 million project is one of the biggest trials of carbon removal in the world, according to the Guardian. The project will explore techniques involving trees, peat, rock chips and charcoal on a 247-acre plot of land.
“This is seriously exciting and pretty much world leading,” Cameron Hepburn, an environmental economist at the University of Oxford who is the lead coordinator of the trials, tells the Guardian. “Nobody really wants to be in the situation of having to suck so much CO2 from the atmosphere. But that’s where we are–we’ve delayed [climate action] for too long.”
The two most straightforward of the trials will involve large-scale planting of trees and bioenergy crops, including Miscanthus grasses and coppice willow, reports Robert Lea for AZoCleanTech. The tree-planting trial will seek to determine the tree species that are most efficient at removing carbon dioxide from the atmosphere in various locations, while the bioenergy trials may burn the grasses to create carbon-neutral fuels or find ways to store the accumulated biomass underground.
In degraded peatlands in the South Pennines and West Wales, another trial will try to promote the formation of peat, a thick mat of organic matter that forms in some bogs, which is known to store vast quantities of carbon. Researchers will try to boost the unique landscape’s powers of carbon sequestration by replanting and re-wetting, per the Guardian.
The final two methods in the trials will use silicate rocks, which absorb carbon dioxide, and biochar, a type of carbon-rich charcoal-like substance. The crushed rocks will be spread over farm in Devon, Hertfordshire and mid-Wales in hopes of sucking greenhouse gases into the soil and keeping them there. Biochar is made by superheating plant matter in the absence of oxygen, and the trial will explore burying it and spreading it over farmland as methods of storing its captured carbon, according to materials from UKRI.
Speaking with the Guardian, Hepburn emphasized that carbon capture can’t replace efforts to reduce emissions and that both are vital to averting climate disaster.
“We are very alive to the possibility that companies will just use offsetting as greenwashing,” Hepburn tells the Guardian. “Part of what this program is about is to develop the monitoring, reporting and verification frameworks to ensure that removals are genuine.”
The announcement of these trials comes roughly six months ahead of the United Nations’ Climate Change Conference of Parties in Glasgow, Scotland, in November 2021, where countries around the world will meet to discuss strategies for addressing the global climate crisis. Per AZoCleanTech, the results of these trials could help decide future investments in carbon removal even beyond the United Kingdom.