The Guardian reports:
Governments have signalled an end to the fossil fuel era, committing for the first time to a universal agreement to cut greenhouse gas emissions and to avoid the most dangerous effects of climate change at crunch UN talks in Paris. …
The deal set a high aspirational goal to limit warming below 2C and strive to keep temperatures at 1.5C above pre-industrial levels – a far more ambitious target than expected, and a key demand of vulnerable countries. It incorporates previous commitments from 186 countries to reduce emissions which on their own would only hold warming to between 2.7C and 3C.
It’s a good thing 200 Governments managed to get an agreement. That is a huge advance on the Kyoto Protocol which was around 30 countries only.
The business as usual projections for future temperature rises were around 4.5C above pre-industrial levels. This, and previous agreements, now has a track of around 3C. It is possible that future technology may find some way to efficiently extract greenhouse gases from the atmosphere to get it closer to 2C. I don’t think there is anyway it will peak at 1.5C as we are already at over 1.0C.
As I previously blogged, when you take the temperature decade by decade, there has been a large increase since the 1970s. Even if you don’t find reliable the pre 1970s measurements, the trend for the last 50 years is pronounced.