A serious, long-term reduction in global average temperatures at this point would be nothing less than a miracle.   It is not going to happen.   CO2 in the atmosphere is the highest it has been for millions of years.  On 4/18 CO2 was at 410.28 ppm.   
http://www.climatecentral.org/news/the-last-time-co2-was-this-high-humans-didnt-exist-15938