What the UN’s INDC Report tells us:
- Total CO2e emissions per year will increase about 7% under the INDCs.
- Emissions per capita declined by 4% from 1990 to 2010, and will decline by 5% from 2010 to 2030. This suggests that the already existing trend would decrease emission by another 4% by 2030, and thus that the effect of the Copenhagen Accord pledges and the Paris INDCs is only a 1% further reduction in emissions
- If the INDCs work as poorly as predicted, it will be far harder (and more costly) to hit the 2°C target that it would be if we started emission reductions today.
How the UN calculates the effect of INDCs
The UN makes no attempt to correct out-of-date predictions of business as usual. Instead it averages a set of 22 Pre-INDC trajectories devised for the IPCC’s Fifth Assessment Report, which means they used data only through about 2011, the last year of China’s rapid growth in coal use.
So the trajectories do not account for China’s reaction to its increasingly deadly smog problem. China’s business-as-usual (what it would do if it ignored the climate) has been dramatically affected by its recent anti-domestic-pollution policies. As a result the UN’s Pre-INDC trajectories are significantly too high, which makes it look like China’s INDC includes a strong climate component. In fact China’s INDC appears to contain no climate component at all.
In more detail:
- The full Oct-30 UN Report on INDCs
- CO2e emissions will increase from ~51 billion tons per year in 2015 to about 56.7 billion tons per year in 2030, an 11% increase. (#33 and Figure 2). The INDCs cover only 1/3 of that time period, hence our best guess from the limited report data is that CO2e emissions will increase 7% under the INDCs.
- According to paragraph #35, “Global average per capita emissions considering INDCs are expected to decline by 8 and 4 per cent by 2025 and by 9 and 5 per cent by 2030 compared with the levels in 1990 and 2010, respectively.”
- It’s sufficient to consider “by 9 and 5 per cent by 2030 compared with the levels in 1990 and 2010.” That means a 5% decline from 2010 to 2030, so to have a total decline of 9% over the full 40-year period their must have been a 4% decline from 1990 to 2010.
- This means the 20-year drop in per-capita-emissions during the two pledge periods (2010 – 2030) was only 1% greater than the drop in the previous 20 years (1990 – 2010) when there were no pledges.
- Hence it appears that 20 years of pledges and INDCs will end up reducing per-capita emissions by only 1%.
- Since pledges do not affect population, that means emissions in 2030 will only be about 1% lower due to pledges and INDCs combined.
- That’s not much of an effect for a 20-year effort
- And given the uncertainties in 2030 emissions reported by the UN, 1% is statistically indistinguishable from zero. Basically, the effect of pledges and INDCs is too small to measure.
- According to the UN report (and all reports agree on this closely), the most efficient way to reach 2°C starting today would be to reduce emissions by 16% per decade, starting immediately.
- Any dramatic departure from this approach — in terms of a higher emissions trajectory — would be much less efficient, in other words, much more costly.
- In particular, it would be much more costly to first increase emissions 11% over 15 years and then be forced to reduce them twice as fast — at 33% per decade until well past 2050.
- But that’s exactly what it will take (or something even more costly) if the INDCs play out as predicted.
- Also, if we can’t manage to even stop the increase now, it seems quite hard to imagine that in 2030 the world will suddenly find the will to slash emissions from 56 to 24 Gt over the next 20 years, while countries like India are still in a phase where their emissions are likely to be growing fastest.
- In short, sticking with the INDCs will make it essentially impossible to reach the 2°C target.
Comparing INDCs with Pre-INDC trajectories
The UN report, like the other reports on total INDC impact, makes no attempt to predict what would have happened without the INDCs. Instead it borrows past predictions that are quite out of date and that do not rely on the detailed knowledge of individual-country non-climate policies that is available today. The UN report takes a group of 22 conflicting out-of-date predictions (the Pre-INDC trajectories) and averages them in the hope of getting a more realistic prediction of what would have happened without INDCs. However, the scientists writing this report have been careful not to claim that this average or any of the trajectories is in fact an estimate of what would have happened without the INDCs, although some of the broader statements incorrectly imply that the average is exactly what would have happened.
The best way to understand how mistaken this approach can be is to consider the Chinese INDC. We provide a detailed analysis of the origin of the Chinese INDC here. Essentially, in 2013 and early 2014, the Chinese decided that half a million or more premature deaths per year, including Beijing lifespans shortened by five years, was the limit of environmental damage they could tolerate, and they would have to put an end to their increasing use of coal by 2020. Historically this is unsurprising. As countries get wealthier they systematically begin cleaning up their environment. This has never been because of concern about climate change, and all evidence indicates that China is doing this out of concern for the health of its population. They are not acting as a result of UN negotiations or INDCs. They would have implemented their INDC policies in any case.
This is not a criticism of China and we are not saying that the Chinese policies will not help the climate. We are just making three simple points.
- When the report claims that the slower emissions growth from 2010 to 2030 “reflects the impact of the INDCs” (#34) it has not made its case, because it has not made any realistic estimate of what would have happened without the INDCs.
- If the relatively modest improvements attributed to INDCs have little to do with the climate, then it is foolhardy to believe that the far greater improvements needed after 2030 to fix the climate will be supplied by future climate-motivated INDCs.
A final caution:
It is also import to note the extreme uncertainty in the UN analysis. Even given its unrealistic assumptions, the report does admit that emissions growth could be anywhere from 12% greater to 46% less than in the previous 20 years (footnote #12). Furthermore a historical perspective shows a large drop in the emissions growth rate from the 20-year period after 1960 to the 20-year period after 1980. This clearly had nothing to do with climate policies.
After this, there was an enormous surge in Chinese emissions, which has now ended due to intolerable domestic pollution. It seems quite likely, that most of the effect attributed to the UN and INDCs is actually just the effect of the Chinese deciding their pollution was bad enough. While this will be helpful for the climate, it is not an indication that the world has learned how to control global warming.