>> hydrocarbon, methane, ethane, benzene toluene.en if we stop make methane today, we would still have a lot of methane. >> contributing to making the temperatures hotter? >> yes, yes, changing the composition of the atmosphere as well. >> sayd ismail. >> historically is very high. the rate of change is unprecedented. >> why should we care about the levels of co2? >> we are seeing the indication of the forming of the melting of the polar ice caps is one indicator. and figures from now to compared to 20 years ago are slightly higher. >> jack dibb has some eye opening opinions. >> i don't have a rosy outlook on what the state of the world is going to be in 50 or 100 years. there's going to be some progress but i'm not terribly optimistic. >> why are you so pessimistic? >> countries like the u.s. we are potent emitters and not doing much to reduce them. >> dibb says things could get worst. >> these things you read while flying? >> you definitely see stuff coming from asia, coming halfway across from the u.s. or sometimes halfway across.