On Wednesday the CO2 concentration 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 the nations will not be enough to avoid dangerous levels of global warming. The world must remove the CO2 already present 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 transform it into products.
An American research published last week in Nature suggested that global warming could be slowed down. How? With the emergency deployment of a fleet of "CO2 scrubbers" to remove CO2 with DAC technology.
We need a "Covid model," though. A coordinated action, an economic support almost from times of war. 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 absorbent to separate CO2 from other gases.
The Swiss company Climeworks operates 15 direct air capture machines across Europe. These include the world's first commercial DAC system. Each "scrubber" uses a sort of fan to suck the air into a "collector", in which a selective filter captures the CO2. When the filter is full, like 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
There are a number of obstacles to direct capture of air before it has a possibly decisive impact on climate change.
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: To remove CO2, DAC technology uses less land and water than other negative emissions technologies such as planting forests or storing CO2 in the soil or oceans. And this is perhaps why it is gaining more and more support from large companies. Microsoft, for example, included the technology in its emissions-cutting plan last year.
We look forward
The urgency to remove CO2 from the atmosphere seems like a huge challenge. But not taking action will bring much bigger challenges: more extreme climate and weather conditions, irreversible damage to biodiversity and ecosystems, extinction of species and threats to health, food, water and economic growth.