Have we turned the corner on emissions?

One of these days, the world will get its act together and halt the growth in CO2 emissions. This week, the International Energy Agency reported that the rise in emissions did indeed stall in 2014. According to the announcement, this was the first time in forty years that IEA emissions did not increase, except in years of economic weakness.

When we start to turn the emissions corner for good, this is what it will look like. Although halting emissions growth does not yet put us on the path to meeting the 2°C target, it does at least mean that we might not be destined to follow the business-as-usual path to disaster along the worst-case RCP8.5 pathway. At least we are not going as fast along that road.

Chris Mooney, Climate Nexus and Joe Romm have articles on this, all worth reading.

The IEA announcement was a teaser: we are going to have to wait until June 15, 2015 to see the details of the analysis. In the meantime, I thought it would worthwhile looking at some data to see how confident we can be that this really is a positive signal that we can discern out of the noise and uncertainty.

First, let’s plot year-to-year growth in CO2 emissions, along with global GDP growth, against time:


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Does providing information on geoengineering reduce climate polarization?

This article was originally published at Skeptical Science on March 4, 2013.

Dan Kahan of Yale University and four colleagues have just published an article in Annals of the AAPS titled: Geoengineering and Climate Change Polarization Testing a Two-Channel Model of Science Communication that investigates the effect on study participants’ attitudes to climate change after reading an article about geoengineering. In their abstract, they write:

We found that cultural polarization over the validity of climate change science is offset by making citizens aware of the potential contribution of geoengineering as a supplement to restriction of CO2 emissions.

I will argue here that this experiment achieved no such result because the premise was wrong. Specifically, the information on geoengineering that was presented to the study participants (in the form of a fictional newspaper article) bears no relation to mainstream scientific opinion on geoengineering nor, even, to the opinions of advocates of geoengineering. Geoengineering is portrayed in the fictional newspaper article as a strategy with no uncertainty about how well it might work and, it is claimed, will “spare consumers and businesses from the heavy economic costs associated with the regulations necessary to reduce atmospheric CO2 concentrations to 450 ppm or lower”. This is hardly depicting geoengineering as a “potential solution” or “a supplement” to the restriction of emissions, as is claimed in the abstract of the paper.

In fact, what Kahan et al. have demonstrated is that presenting misinformation dressed up as fact can affect people’s opinions about climate change. That may be interesting as a social science experiment conducted on consenting adults, but it is not much use as a guide to effective public science communication, constrained as it is to tell the truth.
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Consensus, Criticism, Communication

Thanks in good part to our critics, our paper Quantifying the consensus on anthropogenic global warming in the scientific literature keeps getting more attention. It almost seems that you can’t open up a browser without seeing the “97%” meme somewhere. The extra interest prompted by Richard Tol’s recent critical article has maintained the rate of downloads of the paper at 500 per day and has pushed the total to nearly 200,000. The recent buzz has also spurred discussions on And Then There’s Physics, Variable Variability, Twitter, in The Guardian and a renewed line of criticism in a series of articles by Yale University Professor Dan Kahan.

I was surprised—a little shocked even—at some reactions to the release of our consensus paper. I was prepared, of course, for an angry response from those people who maintain that the expert consensus on the basics of anthropogenic climate change is either non-existent or crumbling. But my colleagues and I were never expecting to change their minds.

However, strong and sharply-worded opposition was unexpected from people like Dan Kahan (sarcasm), Mike Hulme (“infamous”), some journalists (“unwarranted attention”) and some climate scientists (satire), none of whom actually dispute the existence of an expert consensus on the basics of anthropogenic climate change. That the criticism often seemed tinged with peevishness (at least before they did some back-tracking) was especially surprising. I never saw our work as in any way undermining their approaches and analyses, but rather complementing them. And the complaints continue.

To give you a flavour of the nature of the recent discourse, here are some Tweets. (Keywords: Haha, doesn’t work, distraction, diversion, Sad, don’t inform, They insult, psychological control):


The apparent anger and the throw-everything-at-the-wall criticism suggest that this is something other than a measured scholarly critique. Let’s first look at the main strands of argument in a bit more detail. Continue reading

Consensus Matters

The publication of the paper that I co-authored, Quantifying the consensus on anthropogenic global warming in the scientific literature,  in May 2013 caused quite a splash. The paper received a lot of positive coverage, including Tweets from Barack ObamaAl Gore and Elon Musk.  (They didn’t always get the details quite right: our survey was of the literature, not of scientists’ opinions and we had nothing to say about how dangerous climate change would be.) The paper has been downloaded, as of June 2nd 2014, 183,335 times, which is a record for any Institute of Physics paper. The editorial board of the journal, Environmental Research Letters, awarded the paper the “Best article of 2013” prize.  The research for the paper was done by a team of unpaid non-specialist volunteers of students and industrial and academic scientists, along with other enthusiasts and the funding for its publication was raised by donations from Skeptical Science readers. No taxpayers were harmed during the making of this article.


Not everybody was pleased to see our work in print. In particular, many people who are unconvinced of the urgency to act on mitigating climate change have been claiming that our study is flawed and biased. Even somebody like economist Richard Tol—who accepts that global warming is real and caused by humans and who acknowledges that there is an overwhelming scientific consensus—has made extraordinary efforts over the past year to get a critique published. He finally succeeded, with the paper Quantifying the consensus on anthropogenic global warming in the literature: A re-analysis published in the journal Energy Policy,. The journal editors somehow came to believe that this article fell within its scope of  being “an international peer-reviewed journal addressing the policy implications of energy supply and use from their economic, social, planning and environmental aspects“.

Energy Policy was good enough to give us a chance to respond, which we did with this short paper, which has now (June 21, 2014) been  published. We were only allowed 1000 words, however, so we wrote a much longer article, published on the Skeptical Science website, detailing the 24 errors that Professor  Tol made. Continue reading

The Carbon Bubble – Unburnable Fossil Fuels – Seminar and Discussion

Originally published at Skeptical Science on March 26th, 2014

The British Columbia Sustainable Energy Association (BCSEA) organizes a series of free seminars on climate change and sustainability issues. BCSEA was founded by Guy Dauncey. On February 11th, 2014 BCSEA held a webinar on the recent work done by the Carbon Tracker Initative. Guy has written a detailed summary of their recent work on the BCSEA webpage.

The seminar starts at 8:30 minutes and a very good Q&A session begins at 39 minutes. The slides that accompany the seminar can be downloaded here.

The presenter is Mark Campanale, the founder and executive director of the Carbon Tracker Initiative. Continue reading

The Editor-in-Chief of Science Magazine is wrong to endorse Keystone XL

Originally published at Skeptical Science on March 3rd, 2014

An editorial by the Editor-in-Chief of Science Magazine, Marcia McNutt, conditionally endorses the Keystone XL (KXL) pipeline. Her argument is that:

  • the absence of the pipeline has not stopped oil sands development and the building of the pipeline will not accelerate oil sands development;
  • President Obama can extract concessions from the Canadians to reduce emissions and upgrade the bitumen in Canada.

Both of these arguments are wrong; let me explain why.

Pipelines promote production

The Mildred Lake oil-sands plant in Alberta. Note the tailings pond behind the huge yellow piles of sulphur, a by-product of bitumen upgrading. The sulphur may come in handy later for use in solar radiation management. Photo Wikipedia

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Hans Rosling: 200 years of global change

Originally posted at Skeptical Science on 31 October 2013

We think we have done more than we have done and we haven’t understood how much we have to do. Hans Rosling

Hans Rosling is a Swedish medical doctor and statistician who is determined (in his own words) “to fight devastating ignorance with a fact-based worldview that everyone can understand”.

Here is a video of him giving a talk on September 28th, 2013 at a public forum that introduced the latest IPCC report. The meeting was hosted by the International Geosphere-Biosphere Programme in Stockholm.

During the talk he asks a couple of questions, one on how many more children there will be in the year 2100 compared to today and another on what percentage of world energy is produced by solar and wind. I was in the minority that got the first one correct, but only because I had already seen one of Rosling’s earlier talks. On the second question, I was among the majority that got the answer wrong. How will you do?

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