Attack on science

Hayhoe: These days, to get attacked, all we have to do is step foot off campus and tell anybody, even a local Kiwanis club, or a local church, or even a group of elementary school kids, that climate change is real, and then the angry letters start to flood in. Mann: Typically the attacks are not really about the science. The attack on the science is a proxy for what is really an effort to discredit science that may prove inconvenient for certain special interests. Oreskes: That’s when I started getting attacked. And that was when life sort of changed, it was a bit going through the looking glass. I started getting hate e-mail. What happened then was I mentioned to a couple of colleagues what was going on, and one of my colleagues at Scripps, at the Scripps Institution of Oceanography, said to me, “You should talk to Ben Santer.

Something sort of similar happened to him.” Santer: I remember sitting in a bar in Madrid with Stephen Schneider, the late Stephen Schneider, immediately after the final sentence had been agreed on in the 1995 report, a sentence that’s forever engraved on my memory. The balance of evidence suggests a discernible human influence on global climate. Here we are at this bar, and Steve says to me, “This changes everything, you know. Your life is going to be changed forever.” I had no idea what he was talking about. I really didn’t. Hayhoe: There is definitely a pattern of what happens: nasty e-mails, complaints to your university, requests for your e-mails, and a lot of attacks online. Mann: Often it takes the form of an attack on individual scientists. It’s part of the strategy of ad hominem attack.

Santer: Go after the scientist. Go after their integrity. Go after their funding. Make life miserable for them. Mann: I have received letters in the mail that in one case contained a while powder that I had to actually report to the FBI. They had to come to my office and investigate this and send this off to a lab to make sure that it wasn’t anthrax or some very dangerous substance that my entire department would have been subject to because of this. Santer: Then there’s the power of the Internet, which really was not available back in 1995, to harness your supporters to go after individual scientists, send them threatening e-mails or worse, and let them know, “We’re watching you. We don’t like you. We don’t like what you do.

” Mann: One of the tactics that you see in climate change denialism is an effort to spin and misrepresent peer reviewed scientific studies. So often studies that say one thing, for example, show that some aspect of climate change is even worse than we thought, will somehow be spun by climate change deniers as if it doesn’t provide evidence for concern. Oreskes: Clearly misrepresenting scientific information, cherry picking scientific data, one egregious example that we talk about in the book is an early work by Jim Hansen that Bill Nierenberg, Bob Jastrow and Fred Seitz take out of context and use it to argue that climate change is caused by the sun when, in fact, if you go back to the original paper, Hansen is arguing exactly the opposite. Santer: I think an additional weapon in the arsenal is Freedom of Information Act requests, which are being used not really to advance understanding or, again, shed light on complex scientific issues but as a tactic to threaten, to intimidate, to throw a spanner in the works to take up your time.

Mann: They will bully editors to try to get them to retract articles that are a threat to their case, their case being that climate change isn’t real, it’s not something to worry Oreskes: The weirdest day of my whole life practically was the day I got a phone call from a reporter in Tulsa, Oklahoma ,who said to me, “Are you aware of the fact that Senator James Imhofe is attacking you?” [laughter] I was like, at that time, I honestly didn’t know who Senator Imhofe was. In fact, I think I had been to Oklahoma maybe once but, I mean, and so I said, “No, I have no idea.” At first I thought he was making a mistake, this was some other, well, I have a very unusual name, so it didn’t seem plausible it was some other Naomi Oreskes. And then he had, he read to me from this speech that Imhofe was making and it was part of what we all are very familiar with now that I was a part of the “global conspiracy,” the scientific conspiracy to bring down global capitalism. And I remember thinking, “Conspiracy?!? Scientists are not that organised.” Santer: hacking e-mails, releasing them, all of these things. The technology has moved on since 1995, but it’s the same playbook: don’t really focus on the science and advancing understanding, contributing, but tear down, destroy.

Hayhoe: I think the best we can do is shield ourselves from the attacks and try not to dwell on them, unless it’s a safety issue, in which case we should take appropriate steps, and try to move on, focusing on what we want to achieve rather than what’s trying to hold us back. Mann: So if you are a prominent scientist, if you participate in the public discourse, as I’ve often said, you better develop a thick skin because you will be attacked personally. Hayhoe: My number one rule of thumb is: do not Google myself. I don’t want to see. My number two rule of thumb is to not read the comments section. I don’t want to know. Oreskes: One of the things that I think is really important us that by writing about these things and by documenting about it in a scholarly way with high standards of documentation, we can explain to our colleagues, our institutions, editors at journal, and the public and the media what this is. Because this is not a scientific debate.

I mean if I have one message that’s what my message has been all along and it still is: this is not a scientific debate; it’s a political debate. But it’s a political debate being made to look like a scientific debate. We now know why people do that. Because it’s a very very effective strategy because if you can make people think it’s a scientific debate then people will think it’s too soon to act. But if people see the truth, if they realise that this is a political debate, that it’s related to people’s ideologies to their values, structures, that gives a whole different cast. So it’s very very important for people to understand the character of what this thing is. Santer: Some things are worth fighting for. That perhaps was the most profound lesson for me back then: that a clear public understanding of the science, doing the kind of thing that you’re doing here, that was truly worth fighting for..

Carbon cycle

House: The carbon cycle is, very simply, it’s about the cycling of carbon through natural systems – through plants, through soils, through the ocean – and back out into the atmosphere. Le Quéré: In the natural carbon cycle, there’s a lot of fluxes of carbon dioxide, so the carbon goes in and out of the ocean, in and out of the terrestrial biosphere every year. House: The carbon is constantly flowing between these different systems and large amounts of carbon moves all the time. Le Quéré: I mean in the terrestrial biosphere, in the trees and the forests, it’s very easy to see. If you live in a place that has a forest area with seasons, you see in the winter the trees they have no leaves, and the spring comes and the leaves build up. This is all good carbon dioxide that goes in the leaves. And in the fall and in the autumn when the leaves fall down then their carbon is emitted back in the atmosphere.

So you have a huge signal there of CO2 going in and out of the atmosphere. House: So the ocean will take up the CO2, it dissolves in the surface of the ocean and also when the ocean will release CO2 to the atmosphere and that depends on the concentration of CO2 in the atmosphere and the concentration of CO2 in the ocean. And they form a balance with each other. There’s a continuous massive exchange of carbon dioxide between the atmosphere on land and the atmosphere on the ocean. That is roughly in balance until we introduce human change. Osborn: The experiment that we’re inadvertently perhaps conducting with the climate system is to move huge volumes of carbon from these stores undergrounds in the form of fossil fuels and bringing them to the surface and burning them and adding this carbon to the atmosphere. Le Quéré: What we’re doing now is putting everything out of balance, so we’re adding carbon to the atmosphere. It’s new carbon. It’s not part of the natural cycle.

It’s one that we’ve dug out of the fossil reservoir where they were stored, and we’ve put them back in the atmosphere. This is new carbon, and it puts the system out of balance. House: Although the human emissions are much smaller than the natural fluxes, the natural fluxes approximately are in balance and so they’re not causing an increase of carbon dioxide in the atmosphere. The human emissions, however are very rapid, and the natural systems don’t have time to respond to them. And so you get a net imbalance of raised carbon dioxide concentrations in the atmosphere. Lunt: It’s unequivocal that the amount of carbon dioxide in the atmosphere is increasing and is increasing fast and is increasing faster than ever. House: Oh the rate of change now is incredibly rapid, and what’s more it’s pushed us outside the bounds of what we’ve seen in terms of atmospheric concentration throughout the Ice Ages. Thompson: We have not had levels of C02 at 400 parts per million by volume in 800,000 years of history. House: In the Earth’s past throughout in and out of the Ice Ages, the concentration of CO2 in the atmosphere ranged between about 180 parts per million to 280 parts per mission.

And it took thousands of year for it to change between those states. The difference is now it’s gone up to 350 and even topping 400 parts per million on a single day basis. And that’s happened over a period of a couple hundred years. Friedlingstein: Every single generation is emitting more than the previous generation because emission of CO2 increased exponentially. We emit it so far, if you start from the beginning, which is like the industrial revolution in 1750 or something, when we start to burn fossil fuel, from that time up until today we emitted something like 2000 gigaton of CO2. More than half of this has been emitted over the last 50 years. Thompson: And we know where that CO2 is coming from because we do the isotopes of the carbon. We know it’s coming from fossil fuels. Le Quéré: So carbon is increasing in the atmosphere, but it doesn’t entirely stay there, so about half of the emission and maybe a bit more than half of the emission that we put in the atmosphere ends up in the natural environment. It ends up in the ocean and in the forest. Friedlingstein: For the carbon cycle today absorbed about half of the emissions we put in the atmosphere, so we emit, as I said, 40 gigaton of CO2 per year, about half of it, 20 gigaton of CO2 are taken back from the atmosphere by the land and by the ocean.

House: There’s a multitude of different processes that remove carbon dioxide from the atmosphere. So for example, CO2 from the atmosphere dissolves in the surface of the ocean and then that’s turned over and taken into the deep ocean. Really for that amount of CO2 to be completely removed from the atmosphere it has to be completely dissolved and go down into the deep ocean. And then we’re talking about geological timescales – so hundreds and thousands of years. Le Quéré: So what happens when we put carbon emissions into the atmosphere, new carbon from burning fossil fuel or from different station, what happens is this takes a long time for this carbon to readjust in the land and ocean. Eventually if we’re prepared to wait long enough, so that’s thousands of years, a lot of this carbon, maybe 70 percent will end up in the ocean, and the reason this takes time is that you have different adjustment times, so the CO2 goes in the surface ocean, it takes about 1 year to dissolve. But how it is transported from the ocean’s surface to the intermediate and to the deep ocean depends on the ocean circulation.

The ocean circulation takes hundreds to a thousand years to mix the entire ocean. That’s the timescale that is really relevant here is taking a molecule of CO2, we’ve put it in the atmosphere, how long is it going to take before it ends in the deep ocean? House: So about 65 to 80 percent of the carbon dioxide pulse that’s put into the atmosphere will be removed within about 2 to 200 years. The rest of it, the remaining 35 percent, will take between 2 and 20 millennia to be completely removed from the atmosphere. So roughly you have to think whatever we’re doing today, whatever CO2 is being emitted, roughly a third of it is going to stick around essentially forever really when you consider it in our lifetime. Pelto: We can’t change the atmosphere, the chemistry, with one of the main constituents carbon dioxide by 25 percent and expect nothing to happen. You change your diet by 25 percent. You decide you’re going to start consuming 25 percent more calories, and you don’t change your exercise or anything else. You can’t realistically expect nothing to happen. And that’s what you have to understand.

If we change fundamentally our atmosphere chemistry, we can’t expect climate to stay the same..

Making sense of the slowdown

The Earth’s climate is controlled by the energy balance at the top of the atmosphere. If more heat enters the atmosphere than leaves, then the planet warms. Adding heat trapping gases changes the balance, which in turn causes warming. Ocean heat measurements show that the planet is indeed absorbing heat. Despite this fact, it is often claimed that the global warming has stopped. This claim is inspired by evidence that warming of the atmosphere has been slower over the past one and a half decades. This slowdown is sometimes called the hiatus. However, there are other factors which affect the atmosphere over shorter periods. These can cause faster or slower warming of the atmosphere. To understand the slowdown in warming, we need to understand some of these factors.

If we look at the global surface temperature over the past 3 decades, there are big changes in temperature from year to year. We know the cause of some of these variations. One of the biggest is the El Nino cycle. El Nino is a phenomena in which heat is stored up in the western Pacific Ocean, and then released to the atmosphere in the eastern Pacific. This happens over the course of a few years. El Nino is not predictable, but we can track it in retrospect through sea surface temperature measurements. If we compare past El Nino cycles with temperature changes over the past three decades, we can see that there is a strong relationship between the two. El Nino years tend to be hot years. Recent years have been dominated by the cool phase of the cycle. This is responsible for some of the slowdown in warming. However, El Nino doesn’t explain everything. There are cooler periods in the early eighties and nineties which don’t fit the El Nino cycle.

These were caused by two major volcanic eruptions, El Chichon and Pinatubo. Dust from the volcanoes spread in the upper atmosphere, cooling the surface. Smaller eruptions happen all the time, but can also affect temperatures. There has been an increase in the number of small eruptions over the past few years, offsetting a bit of the greenhouse warming. Another factor is the solar cycle. Satellites tell us that the sun varies in brightness with the sunspot cycle. The last cycle has been particularly weak. A dim sun also offsets a little bit of warming. Yet another factor is pollution. Rapid industrialisation in Asia has led to more particulate pollution in the atmosphere, which also has a cooling effect. The final factor is in the observations themselves. Two of the major temperature data providers, the UK Met Office and NOAA, don’t include the Arctic in their global temperature calculation, because there are no weather stations there.

But the Arctic has been warming faster than anywhere else on the planet. Missing it out leads to an underestimation of the rate of warming. To recap, greenhouse gases have continued to grow over the last one and a half decades. But over the same period, volcanoes, the weak sun and pollution have had a cooling effect, and the rate of warming has been underestimated as well. Two recent studies have put all of these together. If we ignore the short term influences, climate models predict faster warming than we have observed. However, if we use global temperature estimates, and add the influence of El Nino, volcanoes, the weak sun and pollution into the models, then the agreement is good. What can we conclude from this? When we put everything we know into the models, the answers match what we observe. So the slowdown in warming makes sense in retrospect, and doesn’t give us a reason to doubt the models.

However, we couldn’t have predicted it in advance, because we can’t predict volcanoes, pollution or the sun. The slowdown in warming has created a whole family of myths with different levels of sophistication. At one extreme, it is possible to argue that the hiatus should reduce our estimates of climate sensitivity. This is a genuine scientific argument, although the analysis we have just seen suggests that no reduction is required. At the other extreme, it is sometimes claimed that the hiatus disproves the role of CO2 in global warming. They claim that CO2 has increased, but the world hasn’t warmed. This is an example of a strawman, and a complex cause fallacy. Climate science doesn’t claim that CO2 is the only factor which affects temperature. This is why the hiatus is so hard to deal with. The myths may be wrong, but they are simple and convincing. The complex cause fallacy exists because people like things to be simple, but explaining the complex drivers of climate is hard. But in the end, all the hiatus myths revolve around drawing attention away from the big picture. When we look at the big picture, the hiatus does not change our understanding of human caused global warming.

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