aTTP falsely attacks Bjorn Lomborg’s “Impact of Current Climate Proposals” Paper

The following is a comment to be posted at Bishop Hill, responding to another attempt by blogger ….andThenThere’sPhysics to undermine the work of Bjorn Lomborg. The previous attempt was discussed here. This post includes a number of links, as well as a couple of illustrative screen captures at the foot of the table.

aTTP’s comment is

In fact, you should read Joe Romm’s post about this. He’s showing that the INDCs are likely to lead to around 3.5C which I think is relative to something like the 1860-1880 mean. This is very similar to the MIT’s 3.7, and quite a bit lower than the RCP8.5 of around 4.5C. So, yes, we all know that the INDCs are not going to do as much as some might like, but the impact is likely to be a good deal greater than that implied by Lomborg who has essentially assumed that we get to 2030 and then simply give up.

Nov 11, 2015 at 9:31 AM | …and Then There’s Physics

My Comment

aTTP at 9.31 refers to Joe Romm’s blog post of Nov 3 “Misleading U.N. Report Confuses Media On Paris Climate Talks“. Romm uses Climate Interactive’s Climate Scoreboard Tool to show the INDC submissions (if fully implemented) will result in 3.5°C as against the 4.5°C in the non-policy “No Action” Scenario. This is six times the claimed maximum impact of 0.17°C claimed in Lomberg’s new paper. Who is right? What struck me first was that Romm’s first graph, copied straight from the Climate Interactive’s seem to have a very large estimate for emissions in the “No Action” Scenario producing. Downloading the underlying data, I find the “No Action” global emissions in 2100 are 139.3 GtCO2e, compared with about 110 GtCO2e in Figure SPM5(a) of the AR5 Synthesis Report for the RCP8.5 scenario high emissions scenario. But it is the breakdown per country or region that matters.

For the USA, without action emissions are forecast to rise from 2010 to 2030 by 40%, in contrast to a rise of just 9% in the period 1990 to 2010. It is likely that emissions will fall without policy and will be no higher in 2100 than in 2010. The “no action” scenario overestimates 2030 emissions by 2-3 GtCO2e in 2030 and about 7-8 GtCO2e in 2100.

For the China the overestimation is even greater. Emissions will peak during the next decade as China fully industrializes, just as emissions peaked in most European countries in the 1970s and 1980s. Climate Interactive assumes that emissions will peak at 43 GtCO2e in 2090, whereas other estimates that the emissions peak will be around 16-17 GtCO2e before 2030.

Together, overestimations of the US and China’s “No Action” scenarios account for over half 55-60 GtCO2e 2100 emissions difference between the “No Action” and “Current INDC” scenarios. A very old IT term applies here – GIGO. If aTTP had actually checked the underlying assumptions he would realise that Romm’s rebuttal of Lomborg based on China’s emission assumptions (and repeated on his own blog) are as false as claiming that the availability of free condoms is why population peaks.

Links posted at https://manicbeancounter.com/2015/11/11/attp-falsely-attacks-bjorn-lomborgs-impact-of-current-climate-proposals-paper/

Kevin Marshall

 

Figures referred to (but not referenced) in the comment above

Figure 1: Climate Interactive’s graph, referenced by Joe Romm.


Figure 2: Reproduction of Figure SPM5(a) from Page 9 of the AR5 Synthesis Report.

 

Update – posted the following to ATTP’s blog



 

Lomborg and the Grantham Institute on the INDC submissions

Bjorn Lomborg has a new paper published in the Global Policy journal, titled: Impact of Current Climate Proposals. (hattip Bishop Hill and WUWT)

From the Abstract

This article investigates the temperature reduction impact of major climate policy proposals implemented by 2030, using the standard MAGICC climate model. Even optimistically assuming that promised emission cuts are maintained throughout the century, the impacts are generally small. ………… All climate policies by the US, China, the EU and the rest of the world, implemented from the early 2000s to 2030 and sustained through the century will likely reduce global temperature rise about 0.17°C in 2100. These impact estimates are robust to different calibrations of climate sensitivity, carbon cycling and different climate scenarios. Current climate policy promises will do little to stabilize the climate and their impact will be undetectable for many decades.

That is pretty clear. COP21 in Paris is a waste of time.

An alternative estimate is provided in a paper by Boyd, Turner and Ward (BTW) of the LSE Grantham Institute, published at the end of October.

They state

The most optimistic estimate of global emissions in 2030 resulting from the INDCs is about halfway between hypothetical ‘business as usual’ and a pathway that is consistent with the 2°C limit

The MAGICC climate model used by both Lomborg & the IPCC predicts warming of about 4.7°C under BAU, implying up to a 1.35°C difference from the INDCs, compared to the 0.17°C maximum calculated by Lomborg, 8 times the amount. Lomborg says this is contingent on no carbon leakage (exporting industry from policy to non-policy countries), whilst citing studies showing that it could offset 10-40%, or even over 100% of the emissions reduction. So the difference between sceptic Lomborg and the mighty LSE Grantham Institute is even greater than 8 times. Yet Lomborg refers extensively to the August Edition of BTW. So why the difference? There is no explicit indication in BTW of how they arrive at their halfway conclusion. nor a comparison by Lomborg.

Two other estimates are from the UNFCCC, and Climate Action Tracker. Both estimate the INDCs will constrain warming to 2.7°C, or about 2.0°C below the MAGICC BAU scenario. They both make assumptions about massive reductions in emissions post 2030 that are not in the INDCs. But at least the UNFCCC and CAT have graphs that show the projection through to 2100. Not so with BTW.

This is where the eminent brain surgeons and Nobel-Prize winning rocket scientists among the readership will need to concentrate to achieve the penetrating analytical powers of a lesser climate scientist.

From the text of BTW, the hypothetical business as usual (BAU) scenario for 2030 is 68 GtCO2e. The most optimistic scenario for emissions from the INDCs (and pessimistic for economic growth in the emerging economies) us that 2030 emissions will be 52 GtCO2e. The sophisticated climate projection models have whispered in code to the climate scientists that to be on target for the limit of 2.0°C, 2030 emissions show be not more than 36 GtCO2e. The mathematicians will be able to determine that 52 is exactly halfway between 36 and 68.

Now for the really difficult bit. I have just spent the last half hour in the shed manically cranking the handle of my patent beancounter extrapolator machine to get this result. By extrapolating this halfway result for the forecast period 2010-2030 through to 2100 my extrapolator tells me the INDCs are halfway to reaching the 2.0°C maximum warming target.

As Bob Ward will no doubt point out in his forthcoming rebuttal of Bjorn Lomborg’s paper, it is only true climate scientists who can reach such levels of analysis and understanding.

I accept no liability for any injuries caused, whether physical or psychological, by people foolishly trying to replicate this advanced result. Please leave this to the experts.

But there is a serious side to this policy advocacy. The Grantham Institute, along with others, is utterly misrepresenting the effectiveness of policy to virtually every government on the planet. Lomborg shows by rigorous means that policy is ineffective even if loads of ridiculous assumptions are made, whether on climate science forecasting, policy theory, technological solutions, government priorities, or the ability of  current governments to make policy commitments for governments for decades ahead. My prediction is that the reaction of the Grantham Institute, along with plenty of others, is a thuggish denunciation of Lomborg. What they will not consider is the rational response to wide differences of interpretation. That is to compare and contrast the arguments and the assumptions made, both explicit and implicit. 

Kevin Marshall