You could warm Mars up, over time, with greenhouse gases.

There's no shortage of Democrats who are at least as committed as Schwarzenegger to reducing greenhouse gases.

Sending a container from Shanghai to Le Havre emits fewer greenhouse gases than the truck that takes the container on to Lyon.

Though Africa is not responsible for emitting greenhouse gases, it is suffering the consequences of climate change.

Even if we were to stop putting out greenhouse gases right now, we'd still face decades of warming.

China will soon emit more greenhouse gases than America, but its regime knows if it caps aspirations there will be a revolution.