John Gibbons interviews climate scientist, Michael Mann

Mann enough

‘His ‘hockeystick graph’ became the defining symbol of man-made climate change – and made him a special target of the fossil-fuel lobby’

‘If you as a scientist share the stage with an industry-funded denier, you are implicitly telling the audience that these are two equally credible voices – and they’re not’

John Gibbons interviews Michael Mann

Michael Mann is one of the world’s leading climate scientists. He is director of the Earth Systems Science Centre in Penn State University and has been a lead IPCC author since 2001. His ‘hockey stick graph’ became the defining symbol of man-made climate change – and made him a special target of the fossil-fuel lobby. He is author of ‘The Hockey Stick and the Climate Wars’, an insider’s account of the murky world of climate denialism. Mann was implicated in the so-called ‘Climategate’ hacking affair in 2009, but was exonerated of all alleged wrongdoing by several independent investigations.

JG: Mike, you’re best known for your work on the Hockey Stick. Can you tell us about it, why it’s so important, and why it gets you into so much trouble?

MM: The Hockey Stick is this graph my colleagues and I published a decade and a half ago depicting how temperatures, specifically over the northern hemisphere, have changed over the past 1,000 years. We used information from tree rings, ice cores and coral records, what we call climate proxy data. We know the globe has warmed by about a degree C over the past century but the question of how unusual is that warming requires us to go back in time. The record shows relatively warm conditions around 1,000 years ago, a steady, slow cooling trend into the 1900s – and then an abrupt warming over the past century. The shape of that curve is like a hockey stick…what it indicates is that the recent warming really is unprecedented as far back as we can go. This curve became iconic in the climate-change debate – it became a potent symbol in the larger debate over human-caused climate change, and it thus became an object of attack by those looking to discredit the case for concern over climate change. Climate deniers felt if they could ‘take down’ the hockey stick, then somehow the case for concern over human-caused climate change would collapse. Of course, that’s silly because there’s so much other evidence.

JG: Why do you think climate science has become such a red-hot focus of controversy? In other scientific areas, the controversies are in the (peer-reviewed) journals. Why is this one on the street?

MM: The fact is that any time you see the findings of science come into conflict with powerful vested interests, they’ve done their best to try to discredit the science and the scientists. Take tobacco, industry documents actually contained the phrase “doubt is our product”. They manufacture doubt when it comes to scientific findings that pose some potential threat (to their profits). Fossil-fuel interests are pouring in tens of millions of dollars here in the US to discredit the science of climate change, and to discredit arguments for renewables and clean energy. The Koch brothers for instance are funding both.

JG: If the more serious projections coming from climate science (up to 4 degrees C warming by mid-century) are borne out, there’s no future for anybody. Is it not a puzzle that the so-called deniers somehow believe that the impacts won’t affect them?

MM: Denial takes many forms. Those who are orchestrating the disinformation campaign at the top, one might imagine are fairly cynical – it’s quite clear that the fossil-fuel companies know their product is damaging the planet. There may also be some cognitive dissonance. Aside from sociopathic and psychopathic individuals, most people don’t want to believe they’re doing something fundamentally wrong or evil: they may want to believe those individuals who claim that it’s not going to be as bad as the scientists are saying. In other cases it’s almost ideological, it’s no longer a matter of logically looking at the scientific evidence, they see (opposition to) climate change as just another part of their cultural and ideological identity, like their stance on gun control or healthcare. In the US, belief in climate change is about as good a predictor of party affiliation as anything in this country…part of the explanation is changes in our (US) media environment; it’s now possible to isolate yourself in a bubble of self-reinforcing sources of disinformation. A study found that people who habitually watch Fox News are actually less informed.  The article title was Watching Fox News makes you dumber! In US politics, you don’t need to win the argument, you just need to divide the public.

JG: Ireland doesn’t have the US-style ideological chasm, but instead we have a media that is tremendously uninterested and uninformed. Our leading climate scientist, Prof John Sweeney had to actually boycott a recent TV programme, on the grounds that this type of ‘debate’ (giving oxygen to known climate deniers) is feeding the problem – you’ve experienced this?

MM: Sometimes, if you don’t participate, the fear is that people are only going to hear from the voices of   disinformation but if we allow that sort of ‘false balance’ approach, it does a disservice to the public. If you as a scientist share the stage with an industry-funded denier, you are implicitly telling the audience that these are two equally credible voices – and they’re not. I’m sympathetic to the view that John Sweeney expressed about the fallacy of false balance. It’s like an astronomer getting into a debate with the president of the Flat Earth Society over the latest stellar observations.

JG: Conventional scientists tend to ‘stay out of the fight’ and can be critical of those who do engage. What shaped your decision to get into the fight?

MM: As a young scientist at the University of Virginia, I very much shared the viewpoint described, that somehow we scientists have to preserve our scientific purity, yet if you look back at a scientist like Einstein, he played a very profound role in the political discussion (on developing nuclear weapons). This is a different sort of threat, a threat the whole world is being subjected to by human-caused climate change, but an even greater existential threat to civilisation.

JG: You have a young daughter, as I do. is this where climate science for you becomes personal?

MM: Yes it does. To me, this is a matter of intergenerational ethics, making sure we do not make decisions today that guarantee the fundamental degradation of this planet for our children and grandchildren. At no time before, in my view, have humans been in a position to impact the entire planetary environment including the composition of our atmosphere. With great power comes great responsibility, and we have a responsibility to make sure that we don’t screw it up.

We can look to the past for some cautious optimism. We were in a similar situation regarding ozone depletion and acid rain. This problem (global warming) is larger by many magnitudes. Fossil fuels currently underlie the global economy – Exxon Mobil is the wealthiest company that has ever existed. With that wealth comes a great opportunity to influence, some would say, to buy off, politicians;  advertise misleadingly; and fund front groups to poison the debate over climate change. Yet maybe we’re not that far from the point where we will have the necessary good faith debate about what to do about this problem.

JG: The IPCC’s AR5 report seemed to give some weight to the idea of there being some kind of pause or slowdown in the rate of warming. This was pounced on by those wanted to portray that as a ‘stepping back’.

MM: There’s no pause in global warming. Nothing that’s happened in the last 10 years fundamentally changes our understanding of global warming. The IPCC did not change their forecasts of projected warming. If anything, the IPCC is projecting even more warming. Some of the impacts of climate change are unfolding faster than the climate models say they should be unfolding – disappearance of Arctic ice is outrunning the model predictions, leading to even more warming (albedo effect). Recent articles in leading science journals are arguing that the climate models that project more warming may be the closest to reality. We’re already losing more than a trillion dollars a year from extreme climate-related events – around 1% of our global productivity.  It’s projected to cost far more in the future, but there’s also the threat to human health, to food security, water security, national security. Tobacco is a good analogy, where the science was in decades earlier, and there was a huge cost in human lives for not having acted earlier.

JG: Journalists have (largely) failed to grasp climate change; is that largely because science is so complex for non-scientists and so easy to game?

MM: It’s much more difficult to inform than to confuse. There’s asymmetrical warfare between us scientists and good-faith communicators trying to inform the public discourse, and those looking to pollute it.  Deniers don’t even have to be internally consistent. And that assumes a level playing field, which of course we don’t even have here.

You often see the framing crafted to prey on the hurt and the personally disaffected. I was attacked on a pro-gun website recently by an energy-funded writer arguing that these evil climate scientists want to somehow take away your guns!

JG: What does your line, “If you see something, say something” mean?

MM: It’s a motto from our Department of Homeland Security, if you see something strange or a threat, it’s your duty to report it. We scientists are also citizens and appreciate more than anyone the particular threat of human-caused climate change. We have a responsibility to report this threat that we see.

JG: Common sense tells us that smoking 40 cigarettes a day for 30 years is probably going to harm our health; also that dumping 35 billion tons of CO2 into a finite atmosphere must have an effect. Do you think it’s up to those who disagree to prove their case?

MM: I like the way you frame the question. It gets at the issue of what we call the null hypothesis. We may have arrived at a point where every meteorological event is operating in a different environment. We’ve fundamentally warmed the atmosphere. The default expectation is that the atmosphere is different to the way it was 100 years ago.


The full version of this interview is on