The hockey stick is real!

May 9, 2013

NOTE: Images in this archived article have been removed.

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The ice building of "Monte Senario" on the hills near Florence, in Italy, as it was in early 20th century. At that time, it was filled with snow in winter and it could produce tons of ice in summer. Today, it would be barely able to produce a few ice cream cones; and probably not even that. It is tangible evidence of warming and not just that: it proves that the climate reconstruction called the "hockey stick" is correct in indicating that temperatures have substantially risen up during the past century.

Evidence that you are doing something right in the climate change debate often comes from the denial reaction. Most of the times, messages on climate change are simply ignored but, occasionally, the reaction is strong; sometimes rabid. Then, you must have hit a sensitive point!

The most egregious example of this denial reaction is with the so called "hockey stick" curve, the reconstruction of past temperatures that comes with a shape that vaguely reminds, indeed, a hockey stick. Here is the original curve as proposed by Mann and others which appeared as Figure 2.20 from the IPCC Third Assessment Report of 2001, based on Mann, Bradley & Hughes 1999

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Later studies confirmed the curve, also extending it all the way to about 10,000 years ago in a new study by Shaun Marcott, Jeremy Shakun, Peter Clark and Alan Mix.

Nevertheless, the controversy didn’t die out; on the contrary, it keeps flaring, as you can find yourself by googling the term "hockey stick temperatures." If you mention the hockey stick in any kind of on line debate, it is almost certain that you’ll be attacked by people who will start by stating how surprised they are that you are still believing that old and debunked graph. Entire books have been written with the purpose of "debunking" the hockey stick curve, to say nothing about personal attacks and legal harassment against Michael Mann and other researches in the field.

So, denial has had a certain success with the hockey stick and the question is how do we counter these attacks. It is not easy, but let me try to suggest some strategies on the basis of my personal experience. First, let me list three things that you should NOT do.

1. Climate change denial is grounded in fear. Most people react to bad news by turning away, if they can (this is what I called the "Star Wars Force Push Effect". But for some, fear is so great that they feel that they can’t just turn away; they rather react taking an aggressive denial posture. Since fear is not rational, it cannot be overcome by rational arguments. Trying to discuss the science behind paleoclimate measurements will just make deniers more aggressive. 

2. If you try to defend the scientists who performed these studies, you’ll be subjected to what I call "Desdemona’s trap". In Shakespeare’s play, Desdemona tried to help a friend in need but she succeeded only in reinforcing her husband’s idea that she was betraying him. The more you try to defend a fellow scientists, the more you’ll appear to be in collusion with him/them. In taking this attitude, you’ll simply reinforce the belief that scientists are engaged in a world-wide conspiracy designed to trick the world into believing in the fictional story of climate change.

3. Letting yourself dragged into a heated hockey stick debate is tantamount to disaster. If you are a scientist, most likely you know much more about the matter than your opponents. But this is not a debate that you can win using data and rational arguments. Most people who read the exchanges will have a hard time understanding what is science and what is pseudo-science. We are all human and we react to emotional arguments more than to scientific ones. Once the debate veers into straight accusations and insults, many people may well conclude that scientists are the evil guys of the story.

All right, that’s what is not to be done. What do we do, then? Well, there are no miracle solutions, but I can tell you of a test that I made and that seems to have worked well.

As I described in a previous post of mine, recently I spoke about climate to several of my fellow citizens in the town of Fiesole. I introduced the issue of climate change by showing them something they know well: the ice house that, a century ago, was producing ice in summer.

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The ice house is something they could relate with; surely not a machination of some evil scientists. It was obvious that the old ice house, today, couldn’t produce any amount of ice larger than enough to make a few ice cream cones. So, climate has changed over a century, and it has radically changed. Only after having them understand the local change, I introduced the global temperature measurements, showing them that what we experienced in our town is consistent with the global warming trends. I short I could show to them that the hockey stick is real!

That I coupled with a call to action; emphasizing concrete measures that could be taken to avoid brush fires, to make life more comfortable during heat waves and the like. In this, I followed the advice from Peter Sandman, an expert about risk management, as I described in a previous post.

I didn’t have any denial reaction – as instead it had happened in previous debates in the same town. I was somewhat afraid that someone could have risen up and said "but this winter was cold, so where is global warming?" but that didn’t occur. And it was not the lack of negative reactions; if you have some experience with speaking in public, you can easily feel the mood of the audience. In this case, it was a clearly positive reaction. People understood what I was telling them and agreed with me. They also felt "empowered" at the idea that they could do something practical together.

It doesn’t mean it will work all the time and in all situations – it may be more difficult on line than in real life. But I think it is a good strategy for a variety of cases: start with local evidence of long term warming, something that people can understand. Then, emphasize positive action and don’t enter in useless squabbles

Try it; then you’ll tell me how it worked.

You can read the whole story of the hockey stick debate in Michael Mann’s excellent book "The Hockey Stick and the Climate Wars"



Ugo Bardi

Ugo Bardi teaches physical chemistry at the University of Florence, in Italy. He is interested in resource depletion, system dynamics modeling, climate science and renewable energy. He is member of the scientific committee of ASPO (Association for the study of peak oil) and regular contributor of "The Oil Drum" and "". His blog in English is called "Cassandra's legacy". His most recent book in English Extracted: How the Quest for Global Mining Wealth is Plundering the Planet (Chelsea Green”, 2014. He is also the author of The Limits to Growth Revisited (Springer 2011).

Tags: climate change, climate change messaging, Michael Mann