1.   Can energy efficiency and a greater dependence on natural gas cut carbon emissions sufficiently on their own?

2.   Richer countries must do more to cut back carbon emissions.

3.   Scientists are warning that unless carbon emissions are cut, we could be heading for an environmental catastrophe.

4.   Some attacked the fact that faster growth has been environmentally unsound, creating excessive carbon emissions and destroying natural habitats.

5.   Switching to sources of renewable energy will reduce carbon emissions.

6.   The agreement set strict reduction targets for carbon emissions.

7.   The US refused to sign any international treaty on cutting carbon emissions.