Last Wednesday, the concentration of CO2 in the atmosphere was measured at 415 parts per million (ppm). The highest level in human history, and grows every year.
The Intergovernmental Panel on Climate Change (IPCC) says that even the commitment announced by nations will not be enough to avoid dangerous levels of global warming. The world must remove the CO2 already in the atmosphere, in a process often described as “negative emissions.”
How can CO2 be removed?
CO2 removal can be done in two ways. The first is to improve carbon storage in natural ecosystems. For example by planting more forests. The second is the use of direct air capture (DAC) technology to remove CO2 from the environment and store it underground or turn it into products.
An American research published last week in Nature suggested that global warming could be slowed. As? With the emergency deployment of a fleet of “CO2 scrubbers” to remove CO2 with DAC technology.
A “Covid model” would be needed, however. A coordinated action, an almost wartime economic support. Is removing CO2 with direct air capture worth a political and economic effort of this magnitude?
A few more details on DAC technology to remove CO2
The term “direct air capture” refers to any mechanical system that can remove CO2 from the atmosphere. Plants currently in operation use a liquid solvent or solid sorbent to separate CO2 from other gases.
The Swiss company Climeworks operates 15 direct air capture machines across Europe. Among these, the world's first commercial DAC system. Each "scrubber" uses a sort of fan to suck air into a "collector", in which a selective filter captures the CO2. When the filter is full, as happens with a vacuum cleaner, the collector is closed and the CO2 is stored underground.
Advocates of this technology say they are confident that their projects are destined for large-scale investments and deployments in the coming years. Globally, the market value of DAC technology could reach $ 100 billion by 2030, according to some estimates.
Big challenges on the horizon
Before direct air capture has a perhaps decisive impact on climate change, it must overcome some obstacles.
DAC technology is currently expensive, compared to many alternative ways of capturing CO2 - it could become cheaper as the technology grows. Economic viability would be aided by the recent emergence of new carbon markets where negative emissions can be traded.
Another difficulty: DAC machines process a huge volume of air and, as such, consume a lot of energy. The forecasts to reduce this consumption by 75% are long, there is even talk of 2100: however, the new DAC machines under development will already have slightly reduced consumption.
There are also pros, however: DAC technology uses less land and water to remove CO2 than other negative emissions technologies such as planting forests or storing CO2 in soil or oceans. And this is perhaps why it is increasingly gaining the support of large companies. Microsoft, for example, included the technology in its emissions-cutting plan last year.
We look forward
The urgency of removing CO2 from the atmosphere seems like an enormous challenge. But failure to act will bring much bigger challenges: more extreme climate and weather, irreversible damage to biodiversity and ecosystems, species extinction, and threats to health, food, water and economic growth.
