Making concrete doesn't take that much energy. It's around 130 kWh/tonne[1]. That isn't really all that much: compare to the 280-350kWh it takes to produce a single barrel of crude from the Alberta tar sands[2]. And that energy is increasingly coming from renewable sources, like wind and solar.

That said, Asphalt is probably one of the better uses for crude oil. Sticking it semi-permanently to the ground has got to be better than burning it and releasing all it's carbon into the atmosphere.

[1] http://www.sustainableconcrete.org.uk/energy_efficiency.aspx [2] https://en.wikipedia.org/wiki/Oil_sands#Input_energy

> That isn't really all that much: compare to the 280-350kWh it takes to produce a single barrel of crude from the Alberta tar sands[2].

The "tar sands" are a naturally-occurring asphalt deposit. To make asphalt cement out of it basically just requires digging it up and separating the sand from the bitumen. That's a very small part of the energy required to make synthetic crude.

Carbon doesn't exclusively define pollution.

The problem with concrete is that they cook it with nasty stuff like coal ash. Plants spew all sorts of particulate pollution and mercury. Plus they frequently pollute water sources with stuff like sulfuric acid.

The use of coal ash ("fly ash") in concrete is generally considered a good thing.

It's making use of a waste product (from coal power plants) that otherwise gets dumped into the environment where it can pollute soil and waterways.

Unless you're downwind.