I found this chart to help a lot: http://www.wri.org/resources/charts-graphs/world-greenhouse-gas-emissions-2005 http://www.wri.org/resources/charts-graphs/wor

I found this chart to help a lot: http://www.wri.org/resources/charts-graphs/world-greenhouse-gas-emissions-2005 http://www.wri.org/resources/charts-graphs/world-greenhouse-... Although the data is from 2005. Personally I was surprised by the impact of concrete (it says 5% but some estimates are 9%).