We Could Build Entire Cities Out of Greenhouse Gas Some Day

A team from the University of Newcastle is perfecting a method of capturing carbon emissions and transforming them into carbonate rock bricks. They're just part of a wave of efforts by scientists who hope to tame carbon in order to shape a greener future.

While there are many carbon capture innovations at work, this carbonate rock idea is pretty special. These are real-life bricks, like what you use to build houses. Assuming the trials currently underway go well, we might be building houses or even entire cities out of greenhouse gas in the not-too-distant future. This would effectively solve two problems at once: Cleaning up harmful emissions, and producing green-friendly building materials.

Pretty cool, right? The process itself is actually relatively simple. As explained over at PhysOrg: "The mineral carbonation technology replicates the Earth's carbon sink mechanism by combining CO2 with low grade minerals such as magnesium and calcium silicate rock to make inert carbonates." What's left is a solid brick that has dozens of different uses.

It's at least much better than current techniques. Carbon capture and sequestration—bottling up CO2 used in power plants and burying it underground—isn't a new thing, but it's remained controversial for a few different reasons. On the surface, there's what amounts to a PR problem. Carbon capture sends a message that we're okay with continuing to use climate-wrecking fossil fuels to power our civilization. While carbon capture can help mitigate the damage, fossil fuel production and use is destructive nevertheless. Then again, it's not like we can flip a switch and supply the whole world with green energy tomorrow. The transition to techniques like wind and solar energy will take time.

A more robust complaint is that carbon capture and sequestration requires energy—lots of it. This is more of a challenge than anything, though. Almost all experts say that it's worth investing some resources into carbon capture techniques, otherwise we might miss our goals for reducing carbon emissions in the next few decades. Furthermore, technology will surely improve in years to come, bringing the cost of carbon capture and sequestration down to more reasonable levels. That's a hard sell to power plant owners who would have to invest heavily to gain the capability to capture carbon.

However, the cost of carbon capture starts to look less dreadful if you can do something useful with the carbon dioxide. That's why people are excited about the greenhouse-gas-to-bricks method. Meanwhile, a Texas-based startup called Skyonic is developing a method that would convert spent CO2 into baking soda. And the stuff can always be used to carbonate our soft drinks. The sale of these products offset the overall cost of carbon capture and sequestration, but also do away with the risks of burying the carbon dioxide underground.

Using these kinds of methods, it's actually possible to build emission-free coal-burning power plants. In fact, there's one already being built in Illinois that uses carbon capture and sequestration to deal with the Earth-wrecking greenhouse gases that typically billow out of power plants. All we need now is for people to get really excited about carbonate. The Han Solo connection might help a little bit. At this point, we need all the help we can get. [PhysOrg, Guardian, NYT, Smart Planet, Time]