Demand for aluminum is extremely sensitive to global real GDP.

Aluminum giant Alcoa just announced its Q2 earnings and they were better than expected. And management reiterated its expectation for 7 percent global demand growth for 2012.

The following two slides come from Alcoa's earnings presentation. The first looks at demand growth from industrial end markets. The second looks at demand growth based on regional end markets.

As you can see, 7 percent global demand growth is good, but it's not as good as the 10 percent growth we saw in 2011.