Recently held Paris summit on climate change was a combined effort of all the 195 nations to combat the emission of green house gasses which is the major cause of global warming.
Following are the achievements of the summit; All the nations promise to achieve the goal of limiting global warming to below 2 degree centigrade by 2030 free industrial level
The final draft document of the summit includes the COMMON BUT DIFFERENTIATED RESPONSIBILITY which is a big success and big relief for developing countries.
CBDR means the responsibility to reduce emission is common to all but differentiate that is as developed countries are the largest emitters and developing and least developed countries are the victims of changing climate even though their part in emission is very less.
So it was decided that developed countries must take greater responsibility and should financially to assist the developed nations in combating global warming. By this CBDR developing nations were allowed to emit green house gasses in order to combat their poverty and energy need which developed nations already emitted. Hence CBDR was a big relief for the developing and least developed nations.
One more thing for the accountability of the efforts of the member countries regarding the cutting emissions each country has to submit their measures and report every five years.
There were some failures too at COP21, like there is no obligation on any country regarding the cutting emissions. It was left to countries and only report of their measures every five years sought.
It failed to distinguish between the rich courtiers which are largest emitters like USA China and the least developed nations like Africa which borne the impact of climate change.