Here is a powerpoint from Busby and Asccociates Architects describing some solutions needed to be able to meet the C02 emmisions targets of Kyoto Protocol. "8% of the worlds C02 emmissions come from the production of cement!" Producing one tonne of cement emits approximately one tonne of CO2.
The Kyoto Protocol is an agreement made under the United Nations Framework Convention on Climate Change (UNFCCC). Countries that ratify this protocol commit to reduce their emissions of carbon dioxide and five other greenhouse gases, or engage in emissions trading if they maintain or increase emissions of these gases. Kyoto Protocol - Energy policy of the United Kingdom - United Kingdom Climate Change Bill