how can we contribute in reducing the global warming?

Find out what companies are spewing crap into the atmosphere and boycot their products. On a smaller and personal level, people can stop buying petrol guzzlers. Turn lights off when not in the room. This also goes for tv's etc. Not only will this reduce greenhouse gases, it will also help your pocket. Make sure your house is insulated so you can save on heating and cooling costs. Oh well thats a few anyway.