that really weird and cool thing¶

Just heard that in 2012 alone, we used enough concrete to build a wall around the equator 27 meters tall and 27 meters wide.

And yet, instead of actually doing that really weird and cool thing, we wasted it on stuff like buildings and infrastructure. Booooo. On a more serious note, the production of concrete accounts for about 5% of worldwide carbon emissions, due to the burning of fossil fuels to heat calcium carbonate for making cement, as well as the CO2 released from the calcium carbonate itself as it is processed. I don't know what a good solution for this is. Concrete is the king of construction materials for so many very good reasons, and it remains to be seen if any sustainable alternatives can supplant it.

I'm not well-versed in this field, so if you have insights, I wanna hear them!