The concentration of GHGs in the earth’s atmosphere is directly linked to the average global temperature on Earth;
The concentration has been rising steadily, and mean global temperatures along with it, since the time of the Industial Revolution;
The most abundant GHG, accounting for about two-thirds of GHGs, carbon dioxide ( CO2 ) , is largely the product of burning fossil fuels;
From 1880 to 2012, the average global temperature increased by 0.85°C. Oceans have warmed, the amounts of snow and ice have diminished and the sea level has risen. From 1901 to 2010, the global average sea level rose by 19cm as oceans expanded due to warming and ice melted. The sea ice extent in Arctic has shrunk in every successive decade since 1979 with 1.07 x 106 km² of ice loss per decade.
Given current concentrations and ongoing emissions of greenhouse gases, it is likely that until the emd of this century global mean temperature will continue to rive above pre-industrial level. The world’s oceans will warm and ice melt will continue. Average sea level rise is predicted to be 24 – 35 cm by 2065 and 40 – 63 cm by 2100 relative to reference period 1986 – 2005. Most aspects of climate change will persist for many centuries, even if emissions are stopped.