Alan Watts : In the next 12 years , world is expected to add another billion people . We have to control greenhouse gases to stay on safe side of a 2-degree Celsius limit , he says . According to the World Resources Institute , to stay on the safe side of a 2-degree Celsius increase , we 'd have to go back to the amount we were expelling in 1990 -- and then cut that in half . He says the fastest and easiest way to reduce carbon emissions is climate control . Others : We need to educate women and give them access to contraception .
Alan Watts : In the next 12 years , world is expected to add another billion people . We have to control greenhouse gases to stay on safe side of a 2-degree Celsius limit , he says . He says the fastest and easiest way to reduce carbon emissions is climate control . Others : We need to educate women and give them access to contraception .