The Paris climate agreement, first struck in December 2015, enters into force today. The treaty commits countries worldwide to keep carbon emissions “well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C”.
Countries will pursue self-determined emissions targets, agreed upon before the last round of climate talks, from 2020 onwards. The national targets will be reviewed and strengthened every five years.
The agreement also commits richer countries to provide funding to poorer countries, which have done the least to contribute to climate change but will suffer its worst effects.
As the world embarks on its most dedicated effort yet to prevent catastrophic climate change, The Conversation asked a panel of international experts to give their view on the significance of the agreement coming into force.
Stefan Rahmstorf: Governments should be in emergency mode
The Paris Agreement is the best we could have expected at this point in history. It is a beacon of hope. Almost all nations on Earth have decided to move towards net zero emissions.
It was high time, and in some respects too late. Paris came almost exactly 50 years after the famous Revelle report from the US president’s scientific advisory panel issued a stark warning of global warming, melting ice caps and rising seas due to our carbon dioxide emissions.
The long delay in confronting this threat is not least a result of a major, still ongoing obfuscation campaign by fossil fuel interests.
The goal of the Paris Agreement to limit global warming to 2°C, or better 1.5°C, is necessary. Two degrees of global warming is very likely to spell the end of most coral reefs on Earth. Two degrees would mean a largely ice-free Arctic ocean in summer, right up to the North Pole.
Two degrees would be very likely to destabilise the West Antarctic ice sheet (evidence is mounting that this has already happened). Such an increase might even destabilise the Greenland ice sheet and parts of the East Antarctic ice sheet, locking in more than ten metres of sea-level rise and sealing the fate of coastal cities and island nations.
Some major impacts of our fossil fuel burning cannot be prevented now, thanks to the fateful delays already mentioned. But every 0.1°C of warming we avoid helps contain further massive risks to humanity, including major threats to food security.
Because of all the time that was lost, the remaining emissions budget is very tight: at current rate, we are eating up the budget to stay below 1.5°C (with a 50:50 chance) in about ten years. The budget for 2°C would allow us to keep emitting for about 30 years. If we ramp down emissions rapidly we can stretch these budgets out to last longer, but the key here is to turn the tide of emissions now or we can give up on staying well below 2°C.
If we take the Paris Agreement seriously (and we should), governments around the world should be in emergency mode, taking rapid and decisive measures to get their emissions down.