
this way. We should be able to make cement that
absorbs CO
2
through its lifetime. And we certainly
should be able to build with less concrete.
Covering ground with concrete has negative
effects on drainage, soils, and more. I’m sure we
can do better.
Aluminum
Most aluminum is already made with electricity,
so once again, in theory we can make it without
carbon emissions, but the energy input is not
the only source of carbon. In the arc furnaces
that we smelt aluminum in today the electrodes
are carbon. This is the source of much of their
carbon emissions. Today 69% of aluminum is
recycled in the U.S.
FIX IT: Apple recently worked with Alcoa ...