Part 1: Why should we trust in science?
There is an ongoing controversy in the public sphere – and even within the IOPS community – on whether or not climate change is real. And as much as I appreciate the principle of IOPS to respect and include all, and particularly dissenting opinions, I think we should all agree on one thing: that decisions being made by IOPS should be based in reality and rely (at least as much as possible) on fact(1). Or rather, theory. Which brings me to an important distinction; but before I continue let me make one thing clear.
I am not a climate scientist, nor do I pretend to know all the facts or speak for the climate science community. However, I am a scientist; more precisely, I am a biochemist and I have been working in the field of cancer research for the past 10 years. And I would like to share with you – particularly if you do not come from my “world” – my knowledge on how the scientific community comes to an agreement on a specific topic (it could be climate change, but it might as well be any other, say, why we get cancer – to stay within my own field – or how humans have evolved and where our ancestors came from). Actually, evolution is a good example for another “controversy” in the public sphere that has no foundation in science. But more on that later.
I have been working in science for the past 20 years, but particularly in the last decade I have observed a rising distrust against scientific claims and the trustworthiness of the scientific community in general, particularly in the US. The case is a little different in Europe, where trust in science is still a bit higher in general, and where distrust stems from very different reasons than in the US, but even here less and less people want to actually work in science, which really isn’t good news for the future(2-6). And let me also say that I think that the scientific community deserves a big part of the blame here, for not being able to communicate with the public and for being too self-absorbed, for example. And of course there is fraud, there are ‘bad apples’, there is bad science, there are interests, money and careers involved. After all, scientists are people, too. Still, I’d like to make the case for why we should trust in science and how the control mechanisms in science work.
So how do we actually arrive at scientific claims and predictions like those made in climate science? Let me first insist on one of the most basic concepts in science that is often misunderstood. Or used by some on purpose to distort reality.
Fact - Hypothesis - Theory
Have you ever heard someone say “…yes, but evolution/climate change/you name it is just a theory?” Actually, evolution is a good example for the “it’s just a theory” argument that is used to undermine and obscure the scientific reality and drive people away from science. And it’s the same with climate change.
In science, or I should specify: in my field of the natural sciences, these three words – fact, hypothesis and theory – have a very specific meaning, and in my opinion the scientific community has made a very bad case in explaining the differences in terminology between “everyday language” and “science talk”. Outside of science, you might say climate change/evolution is ’just a theory’ meaning it is a guess or supposition that may or may not be true. You might even use ’hypothesis‘ and ’theory‘ in a similar way, both meaning that you have an idea in your head, maybe based on observations from which you have developed a train of thought and drawn some conclusions that could make sense but are by no means proven to be true. In turn, you might say or hear someone say “a fact is a fact, right? So, if it’s a fact it must be true by definition.” And it follows, then, that if climate change/evolution is not a fact (yet), then it’s just a theory that still needs proof. Until then, nothing is sure.
Because of this common use of these three little words, when you ask first-year students (and unfortunately more and more older ones as well) to put them in order of scientific “value”, the reply very often is theory – hypothesis – fact. Yet, the right answer (again, in my field of the natural sciences; this might be different or less specific in the field of, say, linguistics) is fact – hypothesis – theory.
Scientific facts are basically observations. Not just any observation, of course, but observations that have been confirmed repeatedly and are accepted as true. For example: Animal cells have a cell membrane – fact. The Spegazzini glacier in Patagonia has shrunk dramatically over the past 30 years – fact.
So, in science, facts are pretty low on the scientific scale of “truth”. Only when you have observed – repeatedly and reproducibly – several facts are you able to raise a scientific hypothesis. A hypothesis in “science speak” therefore is a proposition that can be tested by (several) observations or experiments. In order to be considered scientific, hypotheses are subject to scientific evaluation and must be falsifiable, which means that they are worded in such a way that they can be proven to be incorrect.
I am not going to bore you with an example like: does sunlight affect tomato size? I know you can imagine the answer to that one, and of course, hypotheses raised in climate science are much more complex, and therefore much more difficult to answer. But bear in mind two things: a scientific hypothesis is never based on just one observation, but has to be supported by many “facts” or experiments. One experiment alone is not sufficient to prove a hypothesis, because there is always a chance that you made an error somewhere along the way. What you can say is that your results ’support’ the original hypothesis. This means that every experiment that you carry out to ‘prove’ a certain hypothesis has to be repeated several times and has to consistently show the same result. Not only that, but other groups have to be able to repeat the same experiment in their own environment or lab, and come to the same results as well. This is what we call reproducibility.
Moreover, it is usually not enough to ‘prove’ a hypothesis by only one type of experiment. You have to come up with different experiments using different techniques that all come to the same conclusion. To pick a (simplified) example from my own work: Let’s say our hypothesis is ‘gene x causes bone cancer’. This hypothesis is based on the observation that people with bone cancer, who have donated samples of their tumor, have high amounts of gene x in their samples, while biopsies from healthy donors don’t show this phenomenon. Now we can carry out a whole battery of experiments in order to test this hypothesis. For example, we can introduce gene x into normal cells that otherwise don’t cause cancer, and inject these cells into mice (Sorry for all animal rights activists, but this is how it’s done. And I personally know no scientist who likes doing it. A discussion on animal rights issues can/should be had another time.), and see if the mice now develop cancer. Or we can use our cells with gene x in cell cultures (cells in petri dishes, no animals involved) and test how they behave compared to the normal cells. Do they move faster? (this is a hint that they are more aggressive). Do they resist better to chemotherapy drugs? (this is another experiment and another hint). And on and on. Five such experiments (reproducible, done several times) that come to the same conclusion (e.g., yes, cells are more aggressive/cancerogenous) may support our hypothesis and may lead to one single publication in a peer reviewed journal. This can take on average between one and three years. Peer reviewed means that it will be read and evaluated by at least three external reviewers, who are scientists and experts in the same field of science, before it can be published. And I can also tell you from experience that many, many scientific studies don’t make it to publication, because the reviewers judge them to be not scientifically sound enough or lacking in experimental proof.
And this is only the very beginning for our hypothesis of ‘gene x’. Now, we have to prove and prove again that gene x behaves the way we predict over and over again, and other groups all over the world have to do so as well. With different animal species, different cells, different cell types, different techniques. Hundreds, if not thousands of experiments. Then we should also test the counter argument: if we ‘switch of’ gene x in aggressive cancer cells, will these cells become less cancerogenous? And so on. Until there is a general agreement within the scientific community that, yes, gene x is very possibly a player in the development of bone cancer. However, there are other factors (environmental and so on) that may also play a role, and other groups will take care of that field of research.
Once we have several such hypotheses (in some cases, only one hypothesis might be enough, but this is not the rule) we might start calling it a theory. In other words: a scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing. To scientists, a theory is a coherent explanation for a large number of observations or facts (a scientific fact being an observation that has been confirmed repeatedly and is accepted as true) about the natural world. It has to be internally consistent and compatible with the evidence, firmly grounded in and based upon evidence, tested against a wide range of phenomena, and demonstrably effective in problem-solving. So basically, something is not called a theory until it has been confirmed by many independent experiments.
The transition from a hypothesis to a theory is fluent, and even scientists are not very specific in their use of words. This is actually one of the biggest problems in science: although we’d like to be specific, we don’t always stick to our own terminology, mixing “contemporary” use of words with their scientific meaning.
So in the case of climate change, we find both the hypothesis and the theory of climate change used in publications, and sometimes they refer to the same thing. But in any case, no matter what word is used, whatever observations are presented, they have been tested, and tested, and tested again before they are even called a hypothesis. Basically, if evidence accumulates to support a hypothesis, then the hypothesis can become accepted as a good explanation of a phenomenon. One definition of a theory is to say it is an accepted hypothesis. So, next time somebody says “but xyz is only a theory”, a million alarm bells should go off inside your head and a voice should start screaming: “it IS a theory! So it’s based on hundreds and hundreds of facts, repeated and verified by many different people and many different techniques!”
A scientific theory is valid as long as there is no evidence to dispute it. In the case of evolution, which is correctly called the ‘theory of evolution’ there is no scientific evidence that suggests that the theory of evolution is incorrect. No matter what you may have heard otherwise. And you never hear a scientist say the ‘hypothesis of evolution’ because we have long moved past the point of hypothesis. Evolution is one of the best documented theories that are out there. There simply is no dispute in the scientific community on whether or not evolution is true. No peer reviewed journal has ever published a serious article putting forward an alternative theory (or even hypothesis) that explains even remotely as well as evolution how life has evolved on earth. If that were the case, you can believe me that hundreds of labs would jump and run for the opportunity to reproduce data that are this important and fundamental to humanity. Science, in that respect, is a very democratic process, if you will, in which everybody can participate and contribute. But it sometimes does a very bad job transmitting the results to those who haven’t participated!
Climate science is still a young field, compared to evolution for example, or geology. Therefore, a lot of questions are still open, and of course, climate models from the beginning of the studies weren’t always accurate, and some were outright wrong. We neither had the techniques or computer models, nor the body of data that have accumulated over the past 20 or 30 years. However, the basic idea, or hypothesis, of climate change has not changed over the past 20 years. I remember that, in 1988, when I was about to graduate from high school, we spent a whole year in chemistry class discussing climate change, greenhouse gases, acid rain and so on. The predictions back then were horrible, the ozone layer would be gone by 2020, we would go blind from UV rays if we went outside unprotected, the climate would get hotter, and so on. Some of these predictions have turned out to be exaggerated, for sure, but not that much, actually. In some cases, the reality today is even worse than what was predicted back then. Water levels are rising faster and the arctic ice cap is melting much faster than predicted. In fact, it can be argued that overall, predictions have been too conservative, if we take for example the IPCC reports, which have been consistently too careful in their predictions(7,8).
Because of the overwhelming body of data combining rising surface temperatures, ocean temperatures, sea levels, etc. some people now have started saying: yes, global warming is a fact (meaning a theory in the scientific sense), but it is not clear whether it is man-made or not. Here, again, I have to disappoint: this is pure propaganda, since there is no such debate within the scientific community. There are a lot of discussions, of course, on details, models and predictions, but no serious disputes on whether (a) climate change is real and (b) human activity has a significant part in it. In fact, these two things are closely linked by scientific evidence (which will be discussed in another blog).
Of course, if a theory is valid as long as there is no evidence to dispute it, then theories can be disproven. This is the very basis of science: there is no absolute certainty. Not ever. However, so far, nobody has come up with a better theory (or rather, hypothesis), reproducibly tested and peer reviewed, that explains what we have experienced over the past two decades. It would be a huge relief if somebody did.
Since this blog is already quite long, and the aim was to present some background on how the scientific community works, I am going to conclude with a couple of remarks:
First of all, this article does not distinguish between climate change and global warming, nor did I really go into the ’man-made’ controversy or present a lot of ’facts’ on climate science. I wanted to leave this for my next blog, where I intent to write more about climate facts and the consensus within the climate science community, and about how propaganda is done using the example of ’climate gate‘ and the famous hockey stick graph. In fact, while discussing the need to be precise and specific when using scientific terminology, I actually fell for the current propaganda and decided to use ’climate change’ and not ’global warming’ in almost all occasions without defining the scientific meaning of both terms. Sometimes, ’global warming’ would probably have been more accurate. However, the term ’global warming’ has now been hijacked by the “climate change deniers” and almost demonized, and is being used to turn people against the science behind this theory by insisting, for example, that, because some cooling is observed in some areas of the world, the whole theory must be wrong. Therefore, it has almost become a reflex for me to use the more linguistically “neutral” term climate change. There you have it: propaganda in action.
So it seems that both terms ‘global warming’ and ’climate change’ are loaded and make easy targets for skeptics who want to downplay the role of human activity. I read somewhere, and I agree with this, that scientists should present more precise scientific terms to the media and the public, such as ‘enhanced greenhouse effect’, ‘changes to atmospheric composition’, ‘climate disruption’, and ‘human climate forcing’. These terms are less controversial and less politicized than either ‘global warming’ or ’climate change’.
What I wanted to achieve here was raise awareness for the difficulties of the scientific community in communicating precisely and effectively with the media and the public, while at the same time making a very complex field of research accessible to the general public. I count myself as part of the public here, since the field of climate research is so vast and complicated, that it is impossible for me to understand the complex models, calculations, experiments and results in all detail, even if I tried to read the major publications in the field. Just like most of you, I depend on what is presented to me in summarized and simplified form by the media and organizations or other institutions. However, being a scientist, I have insight into the scientific process, and I know about the difficulties in communicating with others about complex issues.
So, to sum up, should you believe that man-made climate change is real? Yes you should. Because it is a fact… or rather a pretty accepted hypothesis. In other words: it’s a theory!
A short list of references, by no means complete…
- IOPS actually has a position (if only interim, as everything so far, but I do hope we will agree on keeping this in) on global warming or climate change, that is expressed in its Vision statement (under Ecological): “The organization seeks new ecological relations that recognize the urgency of dealing with diverse ecological trends such as resource depletion, environmental degradation, and global warming, not only for liberation, but for survival, and that therefore facilitate ecologically sound reconstruction of society
- See what Noam Chomsky has to say in an Article from Feb 2012 (http://www.nationofchange.org/losing-world-1329237182) :
‘At about the same time, the International Energy Agency reported that, with rapidly increasing carbon emissions from fossil fuel use, the limit of safety will be reached by 2017 if the world continues on its present course. “The door is closing,” the IEA chief economist said, and very soon it “will be closed forever.”Shortly before the U.S. Department of Energy reported the most recent carbon dioxide emissions figures, which “jumped by the biggest amount on record” to a level higher than the worst-case scenario anticipated by the International Panel on Climate Change (IPCC). That came as no surprise to many scientists, including the MIT program on climate change, which for years has warned that the IPCC predictions are too conservative. Such critics of the IPCC predictions receive virtually no public attention, unlike the fringe of denialists who are supported by the corporate sector, along with huge propaganda campaigns that have driven Americans off the international spectrum in dismissal of the threats. Business support also translates directly to political power. Denialism is part of the catechism that must be intoned by Republican candidates in the farcical election campaign now in progress, and in Congress they are powerful enough to abort even efforts to inquire into the effects of global warming, let alone do anything serious about it.
In brief, American decline can perhaps be stemmed if we abandon hope for decent survival, prospects that are all too real given the balance of forces in the world.’