“Given the high stakes of climate change, it is foolhardy to rely on #DAC ( direct air capture ) to be the hero that comes to our rescue.” finds new , comprehensive MIT Energy Initiative study*. It highlights the well known, inevitable & painful physics reality of the vast energy requirements of dealing with highly diluted CO2 in the atmosphere: “All-electric DAC deployed at large scale — say, 10 gigatonnes of CO2 removed annually — would require 12,000 terawatt-hours of electricity, which is more than 40 percent of total global electricity generation today.”
The conluding lines sums it up well:
“In their paper, the MITEI team calls DAC a “very seductive concept.” Using DAC to suck CO2 out of the air and generate high-quality carbon-removal credits can offset reduction requirements for industries that have hard-to-abate emissions. By doing so, DAC would minimize disruptions to key parts of the world’s economy, including air travel, certain carbon-intensive industries, and agriculture. However, the world would need to generate billions of tonnes of CO2 credits at an affordable price. That prospect doesn’t look likely. The largest DAC plant in operation today removes just 4,000 tonnes of CO2 per year, and the price to buy the company’s carbon-removal credits on the market today is $1,500 per tonne.
The researchers recognize that there is room for energy efficiency improvements in the future, but DAC units will always be subject to higher work requirements than CCS applied to power plant or industrial flue gases, and there is not a clear pathway to reducing work requirements much below the levels of current DAC technologies.
Nevertheless, the researchers recommend that work to develop DAC continue “because it may be needed for meeting net-zero emissions goals, especially given the current pace of emissions.” But their paper concludes with this warning: “Given the high stakes of climate change, it is foolhardy to rely on DAC to be the hero that comes to our rescue.” “
Definitely worth reading in a desperate World that is getting flooded with ‘silver bullet’ technology solutions to address the climate crisis of our own making. Let me also add that carbon dioxide removal can and will only work on scale as and when we develop corresponding public policies / regulations for its speeding, scaling and sustaining. It is a public good, like traditional waste management. So if and when we decide to be serious about #CDR , it can become part of our everyday life. Until tgis happens it will remain a marginal experimentation and/or playing ground for venture capitalists & Silicon Valley techno-optimists.
* article link below in comments
