Today (2015/10/30) the UN released its report on the aggregate effect of INDCs. The findings are inconclusive, and not very optimistic, so the Newsroom did its best to spin them. For example, it reported:
One of the key findings is that the INDCs will bring global average emissions per capita down by as much as 8% in 2025 and 9% in by 2030.
But if the report says that those are changes starting in 1990, so the 8% and 9% are mainly not due to INDCs, but happened earlier. In fact, the improvement from 1990 until 2010 was 4% and from 2010 to 2030 was 5%. So it appears
that there was an extra 1% drop during a 20-year period, half of which was covered by INDCs. So the INDC contribution might have been 0.5% not 9%.The UN Newsroom also claims, that the report “indicates that together they [the 140 climate plans] can dramatically slow global emissions into the atmosphere. In fact the report finds that global emissions will increase during both the first and second half of the INDC period (2020 – 2030).
But the main Newroom point is merely a distortion and not a fabrication:
Global Response to Climate Change Keeps Door Open to 2 Degree C Temperature Limit
An unprecedented world-wide effort is underway to combat climate change, building confidence that nations can cost effectively meet their stated objective of keeping a global temperature rise to under 2 degree C.
In fact, the weakness of the INDCs make it far more difficult to reach the 2 degree C objective, but they don’t quite make it impossible so, it must be admitted that the door is still open. But there is no doubt that cost effectiveness is decreased substantially.
The increased difficulty is explained at paragraph 41: The rate of emissions decrease after 2030 will need to be about 3.3% instead of the 1.6% that would be needed if we started the decline in 2010 or 2020. Compare this to the fact that under the INDCs emissions will continue to rise.
In fact the report, does not conclude that the INDCs actually change emissions at all from what they would have been. Rather it concludes that emissions will be lower than an average of 22 emission trajectories calculate before 2010. It makes not claim that these accurately measure (or even roughly approximate) what would have happened without the INDCs. And judging by the apparent lack of effect of the INDCs on per-capita emissions, the 22 trajectories probably over-estimate the impact of the INDCs rather dramatically.