No one on the Left has proposed eliminating concrete as a building material.
Then you ignore the Green New Deal.
GND, which is a range of proposals to reduce carbon emissions, does not propose the cessation of all construction. What is being discussed is what you yourself were looking at: lower emissions methods of baking concrete, and so on. Enough with the strawman argument. If other foundation and road and masonry materials, with a lower carbon emission, start shouldering their way in and competing with traditional concrete, that's something you could invest in, instead of making everything political and partisan.