The climate fact no one will admit: 2 °C warming is inevitable [View all]

[GliderGuider]

From the New Scientist:

The climate fact no one will admit: 2 °C warming is inevitable

It is time to start preparing for a world more than 2 °C warmer than now. The UN’s own analysis of what countries are offering to do to limit greenhouse gas emissions shows they fall far short of what’s required. In fact, they suggest the world will have emitted enough carbon dioxide to warm the planet 2 °C by around 2036.

These offers, formally known as Intended Nationally Determined Contributions or INDCs, will be the basis of the global treaty on climate change to be finalised in Paris in December. It was always clear that this treaty would not go nearly far enough to limit warming to 2 °C by 2100, but now the numbers are in.

Ahead of the meeting, 119 INDCs have been submitted, representing 147 countries and 88 per cent of current emissions. The UN has now released a synthesis report analysing what impact they will have. It concludes that even if countries stick to them, annual global emissions will hit 43 gigatonnes of carbon dioxide (GtCO2) by 2030 – and will still be rising.

It has been calculated that to have a 66 per cent chance of limiting warming to 2 °C, cumulative emissions from 2011 must be limited to 1000 GtCO2. The UN report, however, says we’ll have burned through 75 per cent of this carbon budget by 2030. That means we could only emit another 250 GtCO2 after 2030 – which means we’ll bust the budget in around 2036 assuming emissions stay above 40 GtCO2 per year.