There are less intensive alternatives in the use of land, at least on paper. Some are low technology, such as stimulating the soil to store more carbon by limiting or stopping deep plowing. Others are less so, as gadgets to capture CO2 directly from the air or methods that accelerate the natural processes of erosion by which the minerals in the earth’s crust bind to the atmospheric carbon through eons or introduce alkaline compounds into the sea to make it absorb more CO2
This uses a science similar to outdoor CCS, instead of exhaust gases. The problem is that the concentration of CO2 in the air , although it has a high level, according to historical standards, is very low in terms of chemical engineering: only 0.04%, unlike the 10% or more offered by the chimneys of the plant of energy and industrial processes such as cement manufacturing.
Reducing emissions does not solve all that is the secret of climate change
The technologies that exist today and that are being developed by companies such as Global Thermostat in the United States, Carbon Engineering in Canada or Climeworks in Switzerland are still expensive. In 2011, a review by the American Physical Society found that Wilcox contributed extraction costs above $ 600 per ton, compared to an average estimate of $ 60-250 for BECCS.
Improved weathering is at an even earlier stage of development and costs are even more difficult to assess. The estimates range from $ 25 per ton of carbon dioxide to $ 600.
WITCH , built by Massimo Tavoni of Milan Polytechnic, is a model that analyzes climate scenarios and estimates how much research and development funding is necessary to achieve deployment on the scale type that these models predict. For all technologies with low carbon emissions, the figure stands at 65 billion dollars per year until 2050, four times the sum that renewables, batteries and the like attract today.
Even less speculative technologies need immediate investment. Trees take decades to reach their carbon absorption potential, so large-scale planting should start soon, said Tim Searchinger of Princeton University. Christoph Gebald, co-founder of Climeworks , said the first data point on the technology learning curve is $ 600, at the lower end of previous estimates. But like the price of solar panels, he expects his costs to fall in the next few years, perhaps at $ 100 per ton.