Reduce CO emissions2 will not be enough to limit global warming to 1.5° or even 2°C: it will be necessary to eliminate four times more than today by 2050, thanks to forests, but also thanks to cutting-edge technologies that are still in their infancy , according to a benchmark report published Tuesday.
After the inventory, the time has come for quantified objectives: the second edition of an interdisciplinary report coordinated by the University of Oxford establishes that, according to the scenarios of global warming, it will be necessary to eliminate, it is that is to say, capture in the atmosphere and store sustainably, between “7 and 9 billion tonnes of CO2 » per year by 2050.
The first edition of the report (“The State of carbon dioxide removal”) concluded last year that around two billion tonnes were currently being eliminated, mainly through reforestation, compared to the 40 billion tonnes emitted worldwide in 2023.
“In parallel with a rapid reduction of emissions” which remains “the most important strategy”, the elimination of CO2 of the atmosphere “is also necessary” to achieve the objectives of the Paris Agreement, recall more than 50 researchers.
Some are also part of the IPCC, the climate experts mandated by the UN, which recognized the need to eliminate CO2but by giving it a limited role in its scenarios towards “carbon neutrality”.
“If we fail to reduce emissions from fossil fuels and deforestation, the goals of the Paris Agreement will be unattainable, even with strong action to increase CO elimination.2 “, declared William Lamb, one of the authors, Tuesday during the presentation of the report.
CO elimination2 has recently experienced “rapid growth in research, public opinion and start-up » but “first signs of slowdown” are emerging because public policies and funding are not following suit, say experts, who call on governments to integrate the monitoring of these eliminations into their national reduction plan (CDN) provided for by the Paris Agreement .
According to them, the market is currently growing thanks to the demand for carbon credits from companies, contested financial tools, a purchased credit allowing them to offset a ton of CO2 emitted by their operations thanks to the financing of a CO elimination project2 or emissions reduction.
CO vacuum cleaners2 of the start-up company Climeworks, based in Iceland, which has significant underground storage, are a good illustration: two factories currently make it possible to capture and store 10,000 tonnes of CO2 per year thanks to the support of private funds and the sale of carbon credits.
To reach one million tonnes, Climeworks will need several billion euros, just like other young companies, very “uncertain” funding at this stage, according to the report.
Risks for the environment?
For the Center for International Environmental Law (CIEL), this report illustrates a worrying trend that increasingly wants to sell the elimination of CO2 as a solution to climate change. “It’s a distraction from the priority that is […] to get away from fossil fuels,” says Lili Fuhr, from the NGO.
Elimination focuses on CO2 already emitted into the atmosphere, thanks to the restoration or creation of natural carbon sinks (forests, soils, peatlands) but also to new techniques, associated with storage underground or in materials, which represent less than 0, 1% of CO2 currently eliminated, according to the report.
Among them: direct capture from the air with large vacuum cleaners/compressors (DACCS), capture after combustion of biomass to transform it into energy (BECCS), conversion of biomass into biochar (a substance resembling charcoal) , the crushing of rocks that absorb CO2 to spread them on land or at sea…
For the NGO Ciel, certain techniques (DACCS, geoengineering and BECCS) involve “immense risks for ecosystems and communities”.
The authors of the report do not dispute this and highlight the risks of scenarios that depend on these new technologies “some of which involve risks for the environment while others also have co-benefits” in addition to eliminating CO2.
More traditional techniques can also, when poorly executed, prove harmful to “biodiversity and food security”, they add.
This is why they call for “rapid” but “sustainable” and supervised development of CO elimination.2.