#carbon drawdown

[hope-for-the-planet]

How this ordinary rock could stop climate change - The Washington Post

From the article:

When rain pounds earth that contains the right mix of minerals, carbon dioxide in the air dissolves into the water and reacts to form new compounds that imprison carbon dioxide. With enough time, this natural process of literally petrifying the air will cleanse the atmosphere of the carbon dioxide pollution humanity has emitted from burning fossil fuels and other activities. The problem, though, is this natural cycle takes millennia. Kanan’s idea is to take a process that normally operates on geologic time — and speed it up. To do so, his team mixed together limestone with a crushed silicate mineral that contains magnesium — such as olivine, an olive-tinted mineral that can be found around the world. When heated to furiously high temperatures in a kiln, calcium in the limestone and magnesium in the silicate jiggle and switch sides, like participants in a square dance. The result of the chemical reaction is two compounds — magnesium oxide and calcium silicate — that both readily react with air and water to trap carbon dioxide in a matter of weeks. After accounting for emissions from heating the kilns and capturing carbon dioxide from burning limestone, each ton of material can remove one ton of carbon dioxide from the atmosphere, the researchers estimate. “We didn’t expect that it would work as well as it does,” said Yuxuan Chen, lead author of the study who worked in Kanan’s lab while getting his PhD, said in a statement.

[hope-for-the-planet]

I didn't realize carbon capture was a real thing that actually worked (outside of trees, of course!)

Hi Anon!

It is a real thing and it does work! The big caveat is that it definitely isn’t a standalone solution to climate change, but it’s a real technology that has helpful applications in mitigating the climate crisis.

A lot of carbon capture occurs at the emissions source, to capture the carbon dioxide and either pump and store it deep underground or run it through algae scrubbers or a chemical process to capture the carbon dioxide as biofuel, reusable plastic, or other materials.

The caveat here is that a lot of folks are rightfully worried that focusing too much on carbon capture will give the powers that be an excuse to drag their feet in cutting emissions and decarbonizing. Why worry about changing the status quo if a magical technology will come along to bail us out by pulling all those emissions right back out of the air?

Carbon capture also has a lot of significant limitations, such as the amount of energy required to fix a relatively small amount of carbon dioxide. This isn’t my area of expertise, but my understanding is that this technology will probably be most applicable to capture emissions for industries that will be particularly difficult to decarbonize—for example the creation of certain materials that are either exceptionally energy-intensive or inherently release carbon dioxide in their creation (like cement).

So very cool technology, but it’s not going to make a big enough impact on climate change without us also significantly reducing emissions. And it’s not going to replace planting and protecting trees, since nature’s carbon capture is still usually much more energy and resource efficient (as well as all the habitat and climate control benefits)!