David Suzuki: Understanding the science of climate change

Why does the public often pay more attention to climate change deniers than climate scientists? Why do denial arguments that have been thoroughly debunked still show up regularly in the media?

Some researchers from New York’s Fordham University may have found some answers. Professor David Budescu and his colleagues asked 223 volunteers to read sentences from reports by the Intergovernmental Panel on Climate Change. The responses revealed some fundamental misunderstandings about how science works.

Science is a process. Scientists gather and compare evidence, then construct hypotheses that “make sense” of the data and suggest further tests of the hypothesis. Other scientists try to find flaws in the hypothesis with their own data or experiments.

Eventually, a body of knowledge builds, and scientists become more and more certain of their theories. But there’s always a chance that a theory will be challenged. And so the scientists speak about degrees of certainty. This has led to some confusion among the public about the scientific consensus on climate change.

What Prof. Budescu and his colleagues found was that subjects interpreted statements such as “It is very likely that hot extremes, heat waves and heavy precipitation events will continue to become more frequent” to mean that scientists were far from certain.

In fact, the term very likely means more than 90 percent certain, but almost half the subjects thought it meant less than 66 percent certain, and three quarters thought it meant less than 90 percent.

According to an article in New Scientist, the researchers concluded that scientists should use both words and numbers to express certainty.

For example, the IPCC considers “virtually certain” to mean more than 99 percent likely; “very likely” to mean more than 90 percent certain; “likely” to be more than 66 percent; “more likely than not” more than 50 percent; and so on.

It’s important to understand the distinctions. People who recognize the urgency of the situation are more likely to get behind solutions. And businesses and governments are more likely to work toward solutions when the public demands that they do.

And how urgent is the situation? The IPCC has concluded it is “very likely” that human emissions of greenhouse gases rather than natural variations are warming the planet’s surface. Remember, that means they are more than 90 percent certain. That’s about as close to unequivocal as science gets. The IPCC has also concluded that the consequences could be catastrophic.

This is science that has been rigorously peer-reviewed and that has been agreed upon by the vast majority of the world’s climate scientists, as well as more than 50 scientific academies and societies, including those of all G8 nations. There has been no peer-reviewed scientific study that has called into question the conclusions of the IPCC, which represents the consensus of the international scientific community.

So why does the debate still continue? Why are we fiddling while Rome burns? Well, as Prof. Budescu’s research shows, some people don’t really understand how science works. And people with vested interests, many of whom work with the oil and coal industries, are all too willing to exploit that lack of understanding by sowing confusion.

It’s also true that many people fear change. We’ve seen examples of economic prosperity and job creation brought about by investments in green energy in places such as Germany and Sweden. And leading economists, including former World Bank chief economist Nicholas Stern, have warned that not doing anything to confront climate change will cost us far more in the long run than acting now. But many people still fear that any profound change will upset the economy or diminish their quality of life.

We must also consider the rational argument for taking action on climate change. Even in the highly unlikely event that all the world’s climate scientists have got it wrong, if we still move forward to clean up our act, we’ll end up with a cleaner planet and more sustainable technologies and energy sources. On the other hand, if the scientists are right and we decide to listen to the absurd arguments of the deniers, we’re in trouble. It doesn’t seem like much of a choice.

We may never reach 100 percent certainty on climate change and its causes—that’s not what science is about—but one thing is certain: if we don’t get together to work on solutions now we’ll have a much tougher time dealing with the consequences later.

Take David Suzuki’s Nature Challenge and learn more at www.davidsuzuki.org/.




Mar 5, 2009 at 10:59am

This is typical David Suzuki. The title and opening talk about 'science'. The entire article then goes on to describe 'semantics'
On this basis, 3.000 is very likely to be the true value of Pi. Science requires the CORRECT answer. A hypothesis that elevated CO2 in the atmosphere will lead to runaway warming has no place in science any more when we find that increases have not led to heating at all. In fact, the world has traditionally had much higher levels of CO2.

When the results don't fit the hypothesis, it is abandoned. A new hypothesis must deal 100% with the previous failure.

If I ever tried to submit this type of garbage to a REAL scientific journal I would be made a laughing stock.


Mar 5, 2009 at 2:20pm

Science is indeed a process of making hypotheses and then making predictions upon which the hypothesis is based. When the predicted outcome is not the measured outcome, the hypothesis is then discarded and new one is introduced. Two observed climate changes, a global warming 1000 years ago and a mini-ice age ending 200 years ago occurred without man's participation. The recent (since 1800) global warming, sea rising etc occurred 50 years before the first detectable rise in CO2. The last decade has seen a global cooling, in fact, 2008 was the coldest year and similar to the "baseline" period of 1950-1980. CO2 concentrations have risen steadily. Global temperatures have not followed this steady rise. The hypothesis of AGW is being challenged by many precisely because it failed to account for the observations. As scientists should do, one scraps the present hypothesis that does not fit the data and formulates a new one, a dynamic process. Consensus is for media types, politicians, and plays absolutely no role in science. Copernicus certainly was not being politically correct when he said the earth revolved around the sun and not the other way around. As far as I can tell, almost all popular truths, turn out to be fiction when confronted with the "test of time." As a journalist, you may be able to go back even in your own writings to see what was blatantly obvious true in the past, has now become just plain wrong. Healthy skepticism in journalism is multiplied many fold for a scientist.


Mar 5, 2009 at 2:37pm

I think the straight should stop shoving this liberal bullshit down our throats. Try giving us a real scientific article that proves what the great Suzuki enjoys telling stories about.


Mar 6, 2009 at 2:04am

I think this was a great article by the good Dr.. Bill M points out his major thesis. We need to open a new science for the deniers, stupidology. Poor Bill W thinks that proof as represented by an obscure branch of math(ie, arithmetic) is how science works. Too many CSI shows. Is this a failure of our educational system? A joke from when I was at school was" Ya can lead a whore to culture but ya can't make them think". Dr. S is right, we can't allow the dialog to be drug down to the lowest common denominator. Should I teach physics to frogs?


Mar 7, 2009 at 6:00am

I assume Milton has his tongue firmly in his cheek. I posted point by point comments with the text of Dr. Suzuki's article on a blog. If you're interested, there is also another dig at the good doctor there.



Nov 13, 2009 at 12:16pm

Stupidology? It's not a word, but I like it. Not using your brain to think critically is stupidology. Taking a complex area with incomplete and inconsistent data, accepting the word of a few experts, who have their own axes to grind and fortunes to make, and never doubting the so-called "settled science" and "scientific consensus" is stupidology. Any true scientist will tell you science is never settled, and the truth is certainly not defined by some kind of majority vote amongst scientists, so a consensus being proof of anything is, well, stupid. Yep, if 80% of scientists believe the sun revolves around the earth, it must be true, and the other 20% are "deniers". Being a true believer and viewing those who dare to think and have a different view as deniers is stupidology. I would personally eschew coining non-words to describe others if you haven't figured out that the word applies better to the coiner.

Doug Proctor

Dec 14, 2009 at 7:03pm

Take a view from 1850 and we are coming out of the Little Ice Age until 1950 or so by the both the "denialists" and the AGW crowd. Why is the continuation of a 90+ year trend so irrational? Why is the history of the Dorset people, the Vikings and the modern Inuit who came through the open waters of NAmerica prior to the LIA irrelevant? And why will the Greenland ice cap, existent for 700ky now fall apart in the next 50? There is so little common sense and so much ideology to the current situation. Be kind to Mother Earth, and get the government to institute "kind" practices. Just don't mislead, lie or ostracize me to get you way. I'll fight back when I am actually on your side. That's what the "skeptical" position is all about: being manipulated and bullied.