To Avoid Climate Catastrophe, We'll Need to Remove CO2 From the Air

Klaus Lackner has a picture of the future in his mind, and it looks something like this: 100 million semi-trailer-size boxes, each filled with a beige fabric configured into what looks like shag carpet to maximize surface area. Each box draws in air as though it were breathing. As it does, the fabric absorbs carbon dioxide, which it later releases in concentrated form to be made into concrete or plastic or piped far underground, effectively cancelling its ability to contribute to climate change.

Though the technology is not yet operational, it’s “at the verge of moving out of the laboratory, so we can show how it works on a small scale,” says Lackner, director of the Center for Negative Carbon Emissions at Arizona State University. Once he has all the kinks worked out, he figures that, combined, the network of boxes could capture perhaps 100 million metric tons (110 million tons) of CO2 per day at a cost of US$30 per ton — making a discernible dent in the climate-disrupting overabundance of CO2 that has built up in the air since humans began burning fossil fuels in earnest 150 years ago.

Lackner is one of hundreds, if not thousands, of scientists around the world who are working on ways to remove CO2 from the atmosphere, capturing carbon from the atmosphere using plants, rocks or engineered chemical reactions and storing it in soil, products such as concrete and plastic, rocks, underground reservoirs or the deep blue sea.

Some of the strategies — known collectively as carbon dioxide removal or negative emissions technologies — are just twinkles in their envisioners’ eyes. Others — low-tech schemes like planting more forests or leaving crop residues in the field, or more high-tech “negative emissions” setups like the CO2-capturing biomass fuel plant that went online last spring in Decatur, Illinois — are already underway. Their common aim: To help us out of the climate change fix we’ve gotten ourselves into.

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