Climate change / global warming

[SmoothOper]

Virtually all of science is uncertain. As topazg says, the question is the degree of uncertainty.

I think science is more of a method for integrating new information and eliminating uncertainty by testing hypothesis, when possible.

I would keep an eye on the oceans personally. If you look at the ability of micro organisms to terraform the planet, from the cliffs of Dover to the Ozark mountains, to the ancient methanotrophs that metabolized out the methane from greenhouse atmosphere those micro organisms shouldn't be underestimated. Also much of the drought weather this past summer in the US would be considered due to a La Nina which is ironically a cooling trend in the South Pacific that prevents water from being evaporated into the atmosphere, though some say that an increased weather cycle where precipitation is dropped before it reaches the US would be a consequence of a warming trend. Having said that if you look at the major eruption of Laki in Iceland which emmitted 120 million tons of sulfur dioxide. That same year 1783, America gained independence and Europe had a three percent decrease in GDP, the hottest summer(and coldest winter) were observed in Boston.

[CnP]

Out of curiousity...

As a question for those of you who believe that global warming is a serious problem, can you say for how long you've held this belief, and how and when you became convinced? What parts of the science, if any, do you consider uncontrovertible? Are there areas where you think the science is uncertain?

hmm. Since I successfully completed my university degree in the area (1:1) - or perhaps when I completed my phd in the area. Certainly before having spent the last decade working as a scientist in the area... I guess my 'belief' is more a belief in the scientific method and the experience that scientists in general work very hard at what they do.

What do I consider pretty certain - the basic science behind it. Uncertain? Regional change such country X will experience 73.72% more Y.

That's interesting. Can you say what exactly you do in the area? Could you elaborate on what you mean by "the basic science behind it" - this could mean different things to different people? Concerning the scientific method, it would be interesting to know what you consider testable predictions of the theory, what observations we could make that would falsify it, and what efforts you know of that are being made to perform such tests.

Thanks. I'm afraid I might not be able to satisfy your curiosity fully. Anyway a quick answer:

I work in the general area of Climate and Meteorology simulation - modelling rather than observations mainly. I should say straight up that I don't consider myself a 'somebody' at all as I have never been career focused enough. For my phd I looked into the dynamical systems behaviour of the climate system (in simulations) when you include vegetation as a dynamic component of the system (allow it to change in response to environmental change according to a set of given equations). Since then I've worked on a number of modelling projects including using climate model data to investigate prehistoric early human (homo erectus) dispersal out of Africa. I've also been involved in running the UKs latest set of climate change simulations:

http://www.metoffice.gov.uk/research/news/cmip5

I've also done work on modelling the terrestrial carbon cycle and am currently working on a project to simulate small-scale phenomena (cold air pooling in valleys in the UK landscape).

(sorry for the long bio!)

.. anyway by the basic science I meant climate is warming and we are to blame. As for a testable hypothesis there is the problem that we have only one example, one world. We can't do any global-scale experiments on the planet and observe the results (other than the rather unfortunate one we're doing now). That is really a major reason for climate modelling. The climate model includes as good a representation of the climate as we can make, given the limits of our knowledge and limits set by the computing resources available. Equations for the fluid dynamics of Atmospheric circulation, for example, were the first to go in, around the 1980s I think and other aspects such as ocean biology are now included. With these models you can do experiments, i.e. re-run recent history including human emissions of CO2 (and all other climate forcings), for example, or just with natural climate forcing (e.g. solar variability and volcanoes). What you see is that to reproduce the global temperature record you need to include the human emissions terms. Without them you don't see the warming that is observed in the last half of the 20th century. So to summarise, climate models are our best guess at how the climate system works and they strongly suggest we're warming the climate and will continue to do so in the future. Global warming theory existed before the climate models but I personally find this line of reasoning to be the most convincing. It's fairly easy to construct a verbal chain of cause and effect but the models allow the different processes and feedbacks to 'fight it out'.

This is getting rather longwinded I guess. However it's interesting to note that the Met Office (UK again) recently updated it's estimate of global warming over the next decade or so - decreasing it by 0.1 deg C (nothing to do with me), resulting from new modelling results i.e. using the latest model. This is not consistent in my mind with a paranoid agenda of alarmism they are sometimes accused of.

Given that simulations form such a major part of the science behind climate change science, I'll try and say how it could be shown to be false. I suppose something could be demonstrated to be completely wrong in our understanding of the science (e.g. atmospheric radiative transfer) or the models in particular. Perhaps a process that is neglected in our current representations could be shown to be massively important and counter balance 'it all'. There are a lot of observations of the climate state - if it became apparent that there was behaviour in the real world that couldn't be explained by the current modelling paradigm that would also call into question our ability to understand the climate and make predictions. Such developments would come from within the scientific community. Testing the models against observations and developing better representations of different processes is basically what a large number of scientists do with most of their time. If anyone could disprove all other models they would. It would certainly help my career

This is just my take on it all anyway.

[Bill Spight]

Testing the models against observations and developing better representations of different processes is basically what a large number of scientists do with most of their time. If anyone could disprove all other models they would. It would certainly help my career

This is just my take on it all anyway.

I just want to underscore the value of falsification. Unlike people in most other fields of endeavor, scientists strive to prove themselves wrong. They also strive to prove other scientists wrong. While it is true that there is scientific orthodoxy, it is nothing like the orthodoxy of other fields. There may be an extra burden on unorthodox views, but orthodoxy is not simply accepted. Everything comes under scrutiny.

[SmoothOper]

Testing the models against observations and developing better representations of different processes is basically what a large number of scientists do with most of their time. If anyone could disprove all other models they would. It would certainly help my career

This is just my take on it all anyway.

I just want to underscore the value of falsification. Unlike people in most other fields of endeavor, scientists strive to prove themselves wrong. They also strive to prove other scientists wrong. While it is true that there is scientific orthodoxy, it is nothing like the orthodoxy of other fields. There may be an extra burden on unorthodox views, but orthodoxy is not simply accepted. Everything comes under scrutiny.

Orthodox vs. unorthodox isn't all that much of an issue, in science people are mostly concerned with novel or unexpected results, since people tend to be experts in their domains. As for climate change I think there is enough value in developing climate models, that even if they don't prove it one way or the other, the models will get application in other areas, namely weather forecasting, but also in odd other fields such economics and computation.

I would also add that I personally feel that local pollution is a bigger issue, and that I don't like being near large intersections, highways parking lots or coal power plants, as well as heavy factories, I don't need a sophisticated model to tell that is bad.

[topazg]

FWIW, the orthodox vs unorthodox argument varies between fields, but having been working in science for 8 years, it's one of the most influential aspects of the fields I've seen and been involved with (particularly controversial areas).

Science in theory is a wonderful thing - science in practice is often money, power, politics, ego and towing the party line if you want to keep being funded. It's not a new phenomenon (see William Harvey's repeated failures to demonstrate their advances in blood circulation knowledge). In areas where the vested interests are larger (pharmaceutals, mobile phones, tobacco, climate change) the dichotomy between what science should be and science actually is also grows considerably.

It's not restricted to vested interests, and part of it I suspect is when you've built your reputation proving a certain theory or demonstrating a certain way a system works, having some arrogant young upstart trying to publish papers that you perceive as making your life's work fruitless is not the top on people's lists of things to do. I also suspect that simply growing older and more "stuck in a belief you know the way the world works because you've studied so long" is a bigger issue.

To quote Sir Richard Doll, the guy who really made famous the link between lung cancer and smoking (personal conversation): "When you're a post-doc, you read every relevant paper in the field you can get your hands on. When you're an established research scientist, you tend to read only those you write and those of your close colleagues. When you're a senior professor, you don't even always read those you co-author yourself". Go figure

[crux]

I just want to underscore the value of falsification. Unlike people in most other fields of endeavor, scientists strive to prove themselves wrong.

Things may be somewhat different in the field of climate science. There's the famous quote from Prof. Phil Jones to a skeptic: "We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it."

[Bill Spight]

I just want to underscore the value of falsification. Unlike people in most other fields of endeavor, scientists strive to prove themselves wrong.

Things may be somewhat different in the field of climate science. There's the famous quote from Prof. Phil Jones to a skeptic: "We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it."

Actually, that attitude is something that I have observed in physics, math, and biology. It has to do with credentialing. A layman with an agenda can make a mess, and at the same time appear credible to other laymen.

[shapenaji]

I've grown up believing in man-made climate change, my father is a physicist noted for being outspoken on issues of climate, and I grew up with discussions of the science at the dinner table.

My position germinated with the greenhouse effect, but it's progressed since then.

Right now, I'd say that the science that I find most convincing is the lack/removal of planetary countermeasures to the increasing carbon density of our atmosphere, as well as the possible amplification of the effects via the melting of permafrost. The specifics of what will happen are incredibly difficult to simulate, but if the chemistry of our atmosphere is changing in such a way that we can't bring it back to equilibrium, then we're taking huge risks.

In fact, I DON'T trust the current science to tell me *exactly* what will happen, but I'd rather not live in a test-tube at the behest of a Coal CEO. They're acting like kids with a chemistry set.

I actually *HATE* the phrase global warming. Even if it IS factual, folks assume that "Global Warming" implies "Local warming". Our weather system is so complex with so many different mechanisms for heat transfer that local warming isn't guaranteed.

Every time the weather changes or does something unusual you hear folks on either side yelling "Global Warming" or "Global warming is a hoax". Climate simply doesn't work that way, an abundance of extreme weather phenomena supports the conclusion that the climate is changing, but a single event does not.


The biggest danger from climate change is not drought/desertification, floods, hurricanes etc...

The danger is in the risk of the unknown, I can prepare for any one of the above scenarios, but preparing for all of them is impossible.

[crux]

We can do without New York City, Los Angeles, and the Cayman Islands. Too bad about Hawai'i and New Orleans, though. We can even survive our wheat fields becoming desert. We'll adapt. But why should we bring disaster on ourselves?

This is also interesting to me, as I used to think like this as well. May I ask - without googling, what do you believe the rate of sea level rise is? (And perhaps the elevation of Manhattan or Hawaii?)

Has anyone here who is concerned about global warming considered whether there may be benefits to more CO2 in the atmosphere, or to a warmer climate? Or does this kind of thought feel immediately ridiculous, and if so, why?

Actually, that attitude is something that I have observed in physics, math, and biology. It has to do with credentialing. A layman with an agenda can make a mess, and at the same time appear credible to other laymen.

Or he might just find a mistake that the scientist with an agenda has ignored because he got his desired result. In any case, to me the quote indicates a deep lack of understanding of how the scientific method is supposed to work.

[shapenaji]

Has anyone here who is concerned about global warming considered whether there may be benefits to more CO2 in the atmosphere, or to a warmer climate? Or does this kind of thought feel immediately ridiculous, and if so, why?

If there are benefits (And there certainly will be), then we must assume there will be drawbacks as well. Neither the benefits nor the drawbacks will be predictable, unpredictable drawbacks will do considerable damage while unpredictable benefits can't be amplified.

This just strikes me as putting one's faith in a lottery.

Actually, that attitude is something that I have observed in physics, math, and biology. It has to do with credentialing. A layman with an agenda can make a mess, and at the same time appear credible to other laymen.

Or he might just find a mistake that the scientist with an agenda has ignored because he got his desired result. In any case, to me the quote indicates a deep lack of understanding of how the scientific method is supposed to work.

Laymen can certainly get it right once in a while.

But if we're going to make policy decisions, then we have to make the best bet we possibly can, and the odds are better on the scientists. But if you'd like to put all your money on 31 black and spin the wheel, I'd rather you didn't bet all our life savings.

EDIT: Also, I have more faith in the ulterior motives of "interested laymen" than I do in some enormous scientific conspiracy which encourages scientists to abandon their most cherished principle. (Crushing competitor's theories in journal articles)

[crux]

Thanks. I'm afraid I might not be able to satisfy your curiosity fully. Anyway a quick answer:

Thank you for your answers. It matches essentially what I've read elsewhere (both on climate science and skeptical websites), but I find it very helpful to hear it described by someone who is directly involved, to verify the information I have. I hope that on neutral ground like a Go forum we can continue to have a conversation about this topic without the acrimony that usually goes along with it in dedicated forums.

.. anyway by the basic science I meant climate is warming and we are to blame. As for a testable hypothesis there is the problem that we have only one example, one world. We can't do any global-scale experiments on the planet and observe the results (other than the rather unfortunate one we're doing now). That is really a major reason for climate modelling. The climate model includes as good a representation of the climate as we can make, given the limits of our knowledge and limits set by the computing resources available. Equations for the fluid dynamics of Atmospheric circulation, for example, were the first to go in, around the 1980s I think and other aspects such as ocean biology are now included. With these models you can do experiments, i.e. re-run recent history including human emissions of CO2 (and all other climate forcings), for example, or just with natural climate forcing (e.g. solar variability and volcanoes). What you see is that to reproduce the global temperature record you need to include the human emissions terms. Without them you don't see the warming that is observed in the last half of the 20th century. So to summarise, climate models are our best guess at how the climate system works and they strongly suggest we're warming the climate and will continue to do so in the future.

Within this paragraph lies one of the core issues I have with climate science: the concept that you can run "experiments" with models. Personally, I think science must verify its theories in the real world, and a true experiment is only something that is performed on nature. We may think that we learn something by running a model or finding an elegant mathematical theory, but we cannot be certain, we always need a physical system as an unbiased arbiter of truth. The argument "we don't know what else it could be" is dangerous, and it would be easy to find historical examples of where it has gone spectacularly wrong.

Regarding computer models, personally I'm a software guy, and somewhat flippantly I could say I don't trust computers. There's a serious issue however; I know just how easy it is to fool oneself to think that a piece of software you've written is correct only to then find the one logical flaw that makes it collapse. My gut feeling is that trying to model something as complex as the climate is hubris. Even vastly simpler models fail badly - at the start of every Formula 1 season for example, when the cars behave differently on track than they do in the CFD simulation. And in 2008 we saw the mathematical models the economists use blow up all around us; they'd never bothered to check whether those had any connection to the real world.

Since you're working for or with the Met Office - can you tell me how much the climate models you use differ from the weather forecasting ones?

Also, another question I've never really seen answered anywhere - if you need CO2 and feedbacks to explain the late 20th century, how do the models explain the warming period 1910-1940? Greenhouse emissions surely were much lower back then, but the warming occurred at a similar rate at least according to some datasets.

[crux]

EDIT: Also, I have more faith in the ulterior motives of "interested laymen" than I do in some enormous scientific conspiracy which encourages scientists to abandon their most cherished principle. (Crushing competitor's theories in journal articles)

You don't need an enormous scientific conspiracy, you just need normal human biases (confirmation bias mainly) and intellectual fallibilities like groupthink. I don't really expect you to believe me on this, I'm just a random guy on the internet. In lieu of the dozens of links I could post on the issue, I'll resort to the fallacy of appeal to authority. I'd strongly recommend that anyone who's at least a little curious about the issue listen to the following interview: http://prn.fm/2012/08/01/green-front-dr-richard-muller-080112/#ixzz22nkSzW84 (no peeking yet for those who want to answer the question about sea level rise; the interview contains the answer). Prof Muller is celebrated by the interviewers as someone who confirms global warming exists and is caused by humans, so his motivations should not be suspect. A part particularly relevant to our discussion about scientific standards is at 19:00, but the whole thing is very interesting so I'd really recommend people listen to it.

[shapenaji]

You don't need an enormous scientific conspiracy, you just need normal human biases (confirmation bias mainly) and intellectual fallibilities like groupthink. I don't really expect you to believe me on this, I'm just a random guy on the internet. In lieu of the dozens of links I could post on the issue, I'll resort to the fallacy of appeal to authority. I'd strongly recommend that anyone who's at least a little curious about the issue listen to the following interview: http://prn.fm/2012/08/01/green-front-dr-richard-muller-080112/#ixzz22nkSzW84 (no peeking yet for those who want to answer the question about sea level rise; the interview contains the answer). Prof Muller is celebrated by the interviewers as someone who confirms global warming exists and is caused by humans, so his motivations should not be suspect. A part particularly relevant to our discussion about scientific standards is at 19:00, but the whole thing is very interesting so I'd really recommend people listen to it.

Laymen are subject to the same biases, if not more so.

I also see groupthink at work, but in laymen. I see it arising from a fundamental distrust of scientists as liberal, ivory-tower intellectuals who are out of touch with the real world.

Those with this groupthink then apply confirmation bias to any paper which proposes that scientists as a group are wrong.

[SmoothOper]

I also suspect that simply growing older and more "stuck in a belief you know the way the world works because you've studied so long" is a bigger issue.

Like I said the only thing that matters are novel and unexpected findings. As far Health Science no one really considers that a science, since fundamentally they can't do most of their experiments do to ethical issues.

[SmoothOper]

Hmm Black Carbon from fuel.

http://www.nytimes.com/pages/science/index.html