I have just spent the last couple weeks on twitter having heated discussions with a variety of climate change specialists (and many self-styled experts) regarding a tweet I posted on January 12, 2017. The tweet presented a quote from a Mashable.com interview with Dr. Michael E Mann where Dr. Mann made this incredible statement:
“It is the overwhelming consensus of the world’s scientists that our the burning of fossil fuels is not just having ‘an effect,’ but (a) is most likely responsible for all of the warming we have seen over the past half century and (b) is already having damaging impacts on all sectors of our economy,”
My tweet asked the climate scientists on my feed whether they agreed with the statement specifically the use of the word “all”. My expectation was that a reasonable core of climate scientists would agree that Dr. Mann had overstepped the science. This was not the case. Instead, what I got was overwhelming support for Dr. Mann with not a single non-skeptic initially commenting negatively. It was as if Dr. Mann was the pope and the climate community his congregation. Nothing he said could be considered to be anything less than the truth, even if it took huge convolutions of logic to make it true. In the last couple weeks the term “alternative facts” has entered our lexicon. Well in the next few paragraphs I want to unpack Dr. Mann’s “alternative fact” and see if it is indeed defensible. Then I will go into what I feel this means for the climate change debate.
I think we can all agree that the overwhelming majority of scientists believe that anthropogenic emissions of greenhouse gases have resulted in some global warming. But that is not what Dr. Mann said in his email. Instead he went several steps further. He said that it is the “overwhelming consensus of the world’s scientists that “burning of fossil fuels” was “most likely responsible for all the warming we have seen in the past half-century”. To be absolutely clear, he didn’t say “all anthropogenic emissions” but only those associated with the “burning of fossil fuels”.
I think we can also all agree that the IPCC represents the consensus view on climate change. Let’s look at what the IPCC has to say about the anthropogenic causes of global warming. There are lots of potential sources, but the easiest place to look is in the AR5 Summary for Policymakers. You don’t even have to go too deeply into that document; all you have to do is look at Figures SPM.1. It presents the “Total annual anthropogenic GHG emissions (GtCO2eq / yr) by groups of gases 1970 – 2010”. According to this graph the major sources of anthropogenic greenhouse gas emissions are:
- fossil fuel combustion and industrial uses – 65% of anthropogenic greenhouse gas emissions
- forestry and other land uses – 11% of anthropogenic greenhouse gas emissions
- methane – 16% of anthropogenic greenhouse gas emissions
- nitrous oxide – 6.2% of anthropogenic greenhouse gas emissions
- fluorinated gases – 2% of anthropogenic greenhouse gas emissions
Later in Chapter 11 the IPCC clarifies that Agriculture, Forestry, and Other Land Use (AFOLU) is responsible for just under a quarter of all anthropogenic GHG emissions. The EPA suggests that the number is 24% and that this is from the cultivation of crops, livestock and deforestation. The IPCC also indicates that 2.4% of global carbon dioxide emissions are the result of the production of cement.
We can stop there because we are already done. Had Dr. Mann simply said “most” in lieu of “all” he would have been correct but that is not what he said. According to the IPCC the burning of fossil fuels AND industrial uses are responsible for 65% of global greenhouse gas emissions. Unless one is willing to believe that 65% of the global greenhouse gas emissions were responsible for 100% of the observed warming then he cannot be right. Were that the case then someone would have to explain to me how that remaining 35% of the emissions know not to effect the planet so we can teach the rest of the emissions their trick.
The argument that was most commonly made by Dr Mann’s supporters on my Twitter thread was that if it weren’t for aerosols, volcanoes etc… we would have observed greater that 100% of the observed current warming. They argue that based on this it is “likely” that Dr. Mann is correct. While that is an interesting argument it means nothing in this context of this quotation because Dr. Mann explicitly stated that “burning of fossil fuels” was responsible for “all of the warming we have seen [my emphasis] over the past half century“. Observed warming takes into account the negative forcings associated with aerosols; and so brings us back to the original question. It is clear that 65% of the emissions were NOT responsible for 100% of the warming; rather it is clear that 100% of the emissions were responsible for 100% of the observed warming; that is how the climate works.
As a minor side note, several individuals noted that the second half of Dr. Mann’s quotation “is already having damaging impacts on all sectors of our economy” is also demonstrably wrong. This is easily proven since many sectors of our economy have seen little or no effects (and according to some literature some have seen net positive effects), to date, due to climate change. Now that is another kettle of fish that I don’t have time to discuss today but I leave it out there for consideration.
Going back to my original point the question arises: why did not one climate expert step up and say: “You know what; Dr. Mann may have overstated the effects of fossil fuels in his statement”? Why instead did several individuals (including climate scientists) step up to support Dr. Mann’s clearly incorrect statement? To be clear, my twitter feed is not the be all and end all on the topic of climate change. So I did a few searches to find if anyone had been critical about his comments in any of the other usual venues and instead all I found was…crickets? There were lots of comments about the story but none questioning Dr. Mann’s statement. The entire community was mute as Dr. Mann spread his “alternative facts”.
It has been suggested that the Donald Trump’s reliance on alternative facts is something of a loyalty test. That by watching how people respond to the alternative facts he can test their allegiances and know who is going to be loyal and who is not. While I would never put Dr. Mann in the same box as Donald Trump; I would suggest that this is an exactly parallel situation. This is a situation where Dr. Mann’s loyal supporters have decided to give Dr. Mann a pass on the facts, possibly as a sign of loyalty. The problem is that unlike Donald Trump, who is a politician and known for stretching the truth, Dr. Mann is supposed to be a man of science whose credibility rests entirely on that fact that he is supposed to stick to the facts. So when he doesn’t there will be repercussions. The obvious one is that Dr. Mann is one of the faces of climate change science. In a time where we need credible leaders to fight the misinformation being spread by the Trump loyalists having one of your top leaders make claims that are easily discreditable is not a good thing.
Many might ask why I am harping on such a little point? Well the answer is that the monomania of activists like Dr. Mann; and let’s be clear here in this scenario he was acting as an activist not as a scientist, about fossil fuels is resulting in bad policy decisions. As reported by the IPCC, 35% of all greenhouse gas emissions are from sources other than the burning of fossil fuels. If we stopped burning fossil fuels tomorrow the climate change issue would not go away. We have to deal with that other 35% of emissions as well. The activists who have fixated on fossil fuels ignore the bigger picture that the aim of the game is to get to a scenario where we are no longer seeing a monotonic increase in atmospheric greenhouse gas concentrations. This means addressing 100% of the problem not just 65% of it.
Remember there is still low hanging fruit out there that can be addressed immediately. Sending a couple hundred million dollars worth of equipment, men and supplies to Indonesia to put out those peat fires would have a bigger effect on global greenhouse gas emissions than eliminating every car in the United States which will cost trillions. Putting money into stopping the deforestation of the Amazon would be a much better way to spend a dollar than another carbon capture facility in Saskatchewan and would have the added benefit of saving vital ecological niches as well. We need clear thinking on the climate change file and that means real facts and not factoids and sound-bites. So c’mon folks be brave, speak truth to power. When someone makes demonstrably incorrect claims in your name isn’t it time to speak out?