The same can be said for fossil fuel powered generators.
Except that, with the exception of natural gas, you have a lot of other combustion products to deal with. CO2 emissions from cement production are the result of baking the carbon out of the calcium carbonate, and it's relatively pure and therefore easier to deal with.
There are also only ~100 cement plants in the US, versus thousands of fossil power plants.
Where does this number come from? All the articles I have seen put that number at 5% of world CO2 emissions.
-The US produces about 5,500 million metric tons per year of CO2.
-Cement production releases about 1.25 tons CO2 per ton.
-The US produces about 68 million tons (2011) of cement per year.
68*1.25 = 87.5 million tons CO2 per year for cement production. That's 1.5% of the total.
How much does it absorb and what consequences?
33-57% of that which is released during production.
The 0.5 pounds of carbon dioxide equivalent per kilowatt-hour for hydro
Good job cherry picking the worst possible number instead of the one that actually applies. You even went out of your way to quote the article so carefully!
Small run-of-the-river plants emit between 0.01 and 0.03 pounds of carbon dioxide equivalent per kilowatt-hour. Life-cycle emissions from large-scale hydroelectric plants built in semi-arid regions are also modest: approximately 0.06 pounds of carbon dioxide equivalent per kilowatt-hour.
The part you quoted is for tropical zones and peatlands. So how much of the US is in a tropical climate zone, exactly? Hawaii and a little bit of Florida?