Direct air capture (DAC) of CO2 looks like a non-starter at any serious scale. MiT says: ‘For example, one recently proposed design for capturing 1 million metric tons of CO2 per year would require an “air contactor” equivalent in size to a structure about three stories high and three miles long.’ Major problems are also found with energy use, siting/storage and high costs. Although MiT believes in greenhouse gas ’emissions’ removal as an idea, current practicalities tend to undermine it even for such believers. Not wishing to sound too negative, the researchers suggest DAC might somehow become more viable with (unknown) future technical developments, but that won’t impress climate alarmists much.
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In 2015, 195 nations plus the European Union signed the Paris Agreement and pledged to undertake plans designed to limit the global temperature increase to 1.5°C, says MiT research (via Phys.org).
Yet in 2023, the world exceeded that target for most, if not all of, the year—calling into question the long-term feasibility of achieving that target.
To do so, the world must [Talkshop comment – says who?] reduce the levels of greenhouse gases in the atmosphere, and strategies for achieving levels that will “stabilize the climate” have been both proposed and adopted.
Many of those strategies combine dramatic cuts in carbon dioxide (CO2) emissions with the use of direct air capture (DAC), a technology that removes CO2 from the ambient air.
As a reality check, a team of researchers in the MIT Energy Initiative (MITEI) examined those strategies, and what they found was alarming: The strategies rely on overly optimistic—indeed, unrealistic—assumptions about how much CO2 could be removed by DAC.
As a result, the strategies won’t perform as predicted.
. . .
The bottom line
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 tons of CO2 credits at an affordable price. That prospect doesn’t look likely. The largest DAC plant in operation today removes just 4,000 tons of CO2 per year, and the price to buy the company’s carbon-removal credits on the market today is $1,500 per metric ton.
Full article here.
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Image: Photosynthesis [credit: Nefronus @ Wikipedia]
via Tallbloke’s Talkshop
November 22, 2024 at 03:24AM
Iowa Climate Science Education 