Do traffic lights cause pollution?

Green means go; amber shows that lights are about to change and red means to stop; but there is more to stopping because it contributes to global warming.

Traffic lights control the traffic at junctions and have an obvious benefit but they are also said to cause pollution.

People who drive cars, buses and trucks are making pollution worse by not turning their car engines off when they are stopped at traffic lights. When they leave their engines on and the traffic lights are red, waste gases are released from their exhausts.

Not only do traffic lights cause pollution which contributes to climate change; they cause loads of noise as well. So we wondered; could we 'ban' traffic lights or at least try to use alternative ways to control traffic? Or could we change the way they work so they don't stop traffic unnecessarily; at empty junctions or empty pedestrian crossings at night.

If we just get rid of traffic lights without providing an alternative there might be fatal accidents on the road. Traffic lights help people when they are crossing roads. They tell drivers and cyclists when its safe to go. It has been suggested that road users' behaviour would change over time and we learn to drive, ride and cross safely without them. The sensible answer to the question; "should be 'ban' traffic lights?" would surely be no.

There is only one way we can stop cars polluting our planets and that is to stop using them. But some of our 'traffic light' problem could be solved by using roundabouts.

Could the 'roundabout' be an effective way to stop global warming? I know it would be very stressful, having to go round and round but that might be the only way out.