But what if cement could be turned into something that helped remove CO2? A British company is trying to do exactly that.
Typical cement is made by heating limestone or clay to extreme temperatures. That intense heating is major source of the process's CO2 emissions and more emissions are released when the raw material burns.
A London-based company call Novacem has created a cement (patent pending) that uses magnesium silicates, which emit no CO2 when heated. Its production process also runs at much lower temperatures and the cement absorbs far more CO2 as it hardens - about 1.1 tons. So the overall carbon footprint, according to Novacem, is negative because the cement absorbs more CO2 when it hardens that the amount of CO2 expended when the product is created.
This product is not available on a commercial scale yet but Novacem hopes to have it on the market within five years. Already, it has the industry talking. Major construction companies like Rio Tinto and investors like Carbon Trust are interested and asking the tough questions. According to the UK's Guardian, a spokeswoman for Carbon Trust had this to say about the innovation:
"The real challenge is what is the supply chain, who do you need to partner with to take it to market? The million-dollar question is what are the applications of it? If it ends up as decorative applications such as floor tiles, it's quite interesting but not as much as if you get into load-bearing structural stuff."
The British Cement Association is cautious as well, pointing out that the geological availability of the resources and validating whether the cement can meet the structural standards of traditional cement has yet to be determined.
While this particular Novacem product may not see the commercial light of day, other companies are also looking into ways to cut cement's carbon footprint. This line of thinking and innovation is what we need to slow global warming and make our most carbon-intensive industries as efficient as possible.