The story of the past hundred years is one of unparalleled human advances, medically, technologically and intellectually. The foundation for these changes is the scientific method. In every room in your house, there are innovations that in 1912 would have been considered on the cusp of magic. The problem with a hundred years of unabated progress, however, is that its continual nature has made us blasé. We expect immediate hot water, 200 channels of television 24 hours a day, and the ability to speak directly to anyone anywhere in the world any time via an orbiting network of spacecraft. Any less is tantamount to penury. Where once the arrival of a television in a street or the availability of international flight would have been greeted with excitement and awe, and the desire to understand how those innovations came into being, it is now expected that every three months you’ll be queuing outside the Apple store for a new wafer-thin slab of brushed metal, blithely unaware that watching a movie in the palm of your hand has been made possible only through improbable and hard-won leaps in the understanding of the quantum behaviour of electrons in silicon.

With each new generation, the memory of appallingly high child mortality rates, tuberculosis and vast slums grows fainter and fainter. As the past becomes hazy, we start to believe that there can be no other sort of world. We become nonchalant about vaccines, to the point of seeing them as a lifestyle choice akin to a decision to eat only organically farmed fruit, because we attend fewer and fewer funerals of those who died too young. The technology and advances in knowledge that cosset us have removed, to a large extent, the need to use our ingenuity and to think rationally. Believing complete drivel was once selected against; now it gets you an expert slot on daytime TV.

Against this rather depressing introductory backdrop, however, there are faint glimmers of hope, because science, rational think-ing and evidence-based policy-making are enjoying a revival. Part of the evidence for this statement can be found on the pages of a certain type of newspaper, where the idea that there may be an adjudicator above opinion is treated as an affront to the ideology of the columnist. The adjudicator in question is nature, the universe beyond the Notting Hill basement kitchen, and the wonderful thing about nature is that opinions can be tested against it. The key to science is in this simple statement from the Nobel Prize-winning scientist Richard Feynman, who once remarked: “It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is – if it disagrees with experiment it is wrong.”

The assertion is surely uncontroversial, but implementing it can be prohibitively difficult, primarily because it demands that everything be subordinate to evidence. Accepting this is fraught with cultural difficulty, because authority in general rests with grandees, gods, or more usually some inseparable combination of the two. Even in a secular democracy, a fundamental tenet of the system is that politicians are elected to reflect and act upon the opinions of the people, or are at least given temporary authority by the people to act upon their own. Science is a framework with only one absolute: all opinions, theories and “laws” are open to revision in the face of evidence. It should not be seen or presented, therefore, as a body of inviolate knowledge against which policy should be judged; the effect of this would be to replace one priesthood with another. Rather, science is a process, a series of structures that allow us, in as unbiased a way as possible, to test our assertions against Nature.

Let us take the politically controversial issue of climate change as an example. Climate scientists make measurements of observable properties of our planet, such as sea surface temperatures and the area of Arctic sea ice. Over many years, these measurements have formed a large data set. The only grounds for arguing with the data would be specific technical issues with the measurements themselves. One could assert that the satellites measuring sea temperatures were not calibrated correctly, or that there was a methodological error in the measurement of the area of the sea ice. Such criticisms are relatively rare. A more common criticism is of the interpretation of the data using computer models.

All models are, by nature, an approximation to reality. But they are the best we can do, given our current understanding and the power of our computers. The important words here are “the best we can do”. There is no other way of predicting the probability of weather in the future. The only legitimate criticisms would be of specific issues with specific models, or of specific inferences drawn from them. It would certainly be wrong to assert that the ensemble of climate models from various research groups around the world encompassed all possible uncertainties about the future, but it is not logical to attack climate science as a whole, because to do so is to attack scientific method.

The loud criticism of climate science is motivated in the main not by technical objections, but by the difficult political choices with which it confronts us. This is important, because there must be a place where science stops and politics begins, and this border is an extremely complex and uncomfortable one. Science can’t tell us what to do about our changing climate. It can only inform us that it is changing (this is a statement based on data) and tell us the most probable reasons for this given the current state of our understanding. For a given policy response, it can also tell us how likely that response is to be effective, to the best of our understanding. The choice of policy response itself is not a purely scientific question, however, because it necessarily has moral, geopolitical and economic components.

Climate science is one of a series of areas that, for primarily non-scientific reasons, has become controversial; and these controversies risk undermining confidence in the very idea of science. Others are the use of genetically modified crops, vaccination policy and even (God help us) the teaching of evolution in schools. These socio-political-religious controversies risk damaging public confidence in science, partly because of the tactics employed by their advocates, which, if unchecked, will have grave consequences because we live in a society dominated by science. People who rail against science risk becoming disenfranchised, because many of the most important decisions we face as a society have a scientific component. And the larger and more vocal the disenfranchised minority, the less likely we are to make decisions based on the best available evidence and understanding.

Science is the framework within which we reach conclusions about the natural world. These conclusions are always preliminary, always open to revision, but they are the best we can do. It is not logical to challenge the findings of science unless there are specific, evidence-based reasons for doing so. Elected politicians are free to disregard its findings and recommendations. Indeed, there may be good reasons for doing so. But they must understand in detail what they are disregarding, and be prepared to explain with precision why they chose to do so. It is not acceptable to see science as one among many acceptable “views”. Science is the only way we have of exploring nature, and nature exists outside of human structures.

We live in exciting times; our access to knowledge has never been greater, but this also means that humbug and charlatanism are able to creep into our lives with greater ease. We cannot afford to sit back and enjoy the achievements of previous generations, and decide that we are no longer obliged to continue the scientific exploration of nature. Fortunately for us, Michael Faraday was not dazzled by the convenience of gaslight. We must not use our comparative comfort and luxury to elevate opinion above science or, even worse, to argue that scientific progress is no longer desirable or necessary. It would be a gross mistake to assume, for the first time in human history, that there are no great discoveries left to make.

Robin Ince is a writer and comedian. Brian Cox is a broadcaster and professor of physics at the University of Manchester. You can buy their guest edited issue of the New Statesman in shops until Thursday 3 January, or purchase a print or digital version here.