Thar the US and China came out with a joint announcememt on putting a cap onclaimate change and energy has brought some glimmer of hope.We of course will only know the roadmap when the climate summit concludes in December of this year.That aside,China and US represent the two heaviest emitters of Co2.Given the present levels of Co2 emissions,the worl will have to rethink its positons on fossil fuels to stay below the 2 dgree upper limit.Either that or we continue to be battered by rising oceans,severe droughts and heat waves.It is estimated that China alone contributed to about 28% of the global Co2 emission this year.The US has been held back on checking its emissions by the fact that successive governments have resisted going down that line without firm commitments from China to act too.It is now hoped that since these two giant energy consumers have come onbord,some changes may actually take place.