Global warming crisis: One expert’s view
Michael Mann, professor of meteorology at Penn State, dropped by Madison, Wis. last week, and we quizzed him about the state of the climate. Mann’s post-doctoral work1 thesis introduced the “hockey stick,” a graph showing the accelerated pace of warming, based on records of temperature over previous centuries.
Mann’s provocative graph became a core of the effort by former vice-president Al Gore to raise the alarm over global warming. It also became, among global warming deniers, a target of attack. Mann was caught up in the manufactured crisis called “Climategate,” and scourged by some media, leading to a flurry of legal actions from both sides.
The updated “hockey stick” graph
We wanted to know what Mann had learned, and how he thinks about the science of global warming today. Here’s an edited transcript of our conversation:
The Why Files: Is the hockey stick still accurate?
Michael Mann: The most recent IPCC report based on many different groups using different approaches and data, has come to an even stronger conclusion. The recent warming is unprecedented over the last thousand years, and potentially tens of thousands of years. [IPCC reported that “The globally averaged combined land and ocean surface temperature data … show a warming of 0.85°C, over the period 1880 to 2012…”]. But the hockey stick is almost a sideshow; it’s one line of evidence that the warming probably has to do with what we are doing with greenhouse gases. There are dozens of independent lines of evidence for the reality of human-caused climate change. The focus on my study … pretends that one 15 year-old study by one post-doc provides the entire weight of evidence for human caused climate change. It’s a straw-man argument that has been used in a very cynical way, to make it seem like our entire understanding of climate change rests on a house of cards; if you pull out the hockey stick, it collapses. Even if the stick did not exist, even if no paleoclimate data existed, we’d know that human-caused climate change is real, that greenhouse-gas releases pose a threat.
TWF: How are we doing in alternative energy?
MM: The U.S. always prided ourselves as leaders in the global marketplace of ideas and innovation, but we are behind the rest of the world. China and India are pulling ahead in the amount they invest in clean energy. We have a legacy of two centuries of access to cheap, dirty energy. Ironically, it’s the developing world, which does not have that legacy, that seems to be moving to embrace renewable energy, wind, solar and geothermal. In a few countries, like the U.S., entrenched special interests don’t want us to transition away from a reliance on fossil fuels.
TWF: What should be the role of nuclear power in a low-carbon future?
MM: That could be an interesting discussion. Let’s have that discussion in Congress, rather than debating the existence of climate change. What policy and energy alternatives should we use to deal with the climate change problem? We need to hear conservative and progressive voices about the role that nuclear and natural gas should play.
TWF: On climate, are local and regional changes still the biggest area of uncertainty?
MM: That’s where the rubber hits the road. We don’t feel the global average temperature, (except along the coast, where you see its effect on rising sea), we feel the local weather. Climate change might impact what we are already feeling. We’re seeing an increase in extreme weather, widespread drought, record heat. To inform the debate over mitigation or adaptation, we want to know what is coming down the road, to support resilience to climate change we are already committed to.
There is uncertainty in model projections, but uncertainty is not our friend. It’s used as an argument for inaction, but there may be surprises or tipping points, things we have not found with the models, because they are approximations of reality and the impact may be worse than they say.
TWF: With climate such a political issue, are climate scientists obligated to be more public about their work?
MM: When I found myself at the center of attack [during the “Climategate” controversy], I had to make a choice. Would I respond and defend my science, or retreat to my lab? I chose to fight back … moving from a naïve young scientist who found himself at the center of much larger forces that he was not trained to deal with, with attacks by politicians and bad-faith criticism. That’s not the way science works. Real skepticism is the way science works. I think more young scientists are becoming engaged and realizing that science outreach is critical. I cannot think of anything more important than trying to inform this discussion about the greatest challenge that human civilization has dealt with.
Expected average conditions as greenhouse gas pollution continues
TWF: What do you make of the seesaw in public opinion about climate warming — sometimes accepting the reality of change, sometimes denying it?
MM: We have delayed confronting the climate problem because the fossil-fuel industry has funded disinformation for several decades. We knew tobacco-industry products were killing people in the 1950s, but it wasn’t until many decades later that we really acted on policy. The tobacco industry, rather than engaging in a good faith discussion about what to do about the problem, chose to hide the health impacts, to discredit the science. It’s the same playbook with fossil fuels. Delay has costs. In the case of tobacco, we acted decades late, and there were potentially millions of lives lost. Here, we are talking about the health of the entire planet; there is no “planet B” if we screw this one up. But I have no doubt that we will act in time to avert truly catastrophe climate change. I’m an optimist, and I recognize that some conservatives are coming out and embracing the existence of the problem, not trying to deny it.
TWF: Where do you expect average global temperature to be in 50 years?
MM: The precise amount of warming for a given increase in greenhouse gases is uncertain, but the dominant uncertainty is what we choose to do. The toughest thing to do is to predict what our fellow human beings will do, but I hope that we will not leave this problem behind for our children to try to solve. We can still avert 2°C warming, we can stabilize below that. The real danger zone may come in terms of food, water, health or national security. We still have time to avoid crossing that threshold, but to do that, we have to act in the next few years. We hold the future in our hands.
– David J. Tenenbaum
Terry Devitt, editor; S.V. Medaris, designer/illustrator; Yilang Peng, project assistant; David J. Tenenbaum, feature writer; Amy Toburen, content development executive
- Global-scale temperature patterns and climate forcing over the past six centuries, Michael E. Mann et al, Nature, 23 April, 1998. ↩
- The Hockey Stick and the Climate Wars: Dispatches from the Front Lines, Michael E. Mann, Columbia University Press, 2012. ↩
- Climate Efforts Falling Short ↩
- Climate change: A guide for the perplexed ↩
- How Nuclear Power Can Stop Global Warming ↩
- The Sky Is the Limit for Wind Power ↩
- Can Geothermal Power Compete with Coal on Price? ↩