Skip to content
Science, Maths & Technology

Decisive Science

Updated Tuesday 6th September 2005

A look at the principles which guide the scientific decision making process.

A penguin slides along on its belly Copyrighted image Icon Copyright: Used with permission How does scientific decision making influence our lives?
Scientific knowledge has the potential to affect the course of human civilisation and the environment within which we live. It is not the only factor influencing such change, but it can be a profoundly important one. It is precisely because scientific knowledge can make a difference to so many people’s lives that decision making related to scientific issues is often the subject of considerable negotiation and contest. Decisions about whether to allow the commercial planting of novel genetically modified organisms in the UK or to reduce global carbon emissions are important precisely because they matter; they have the potential to change the way we live.

Of course, not every decision made about a scientific issue will have such profound implications. Choosing whether or not to eat beef, for example, is an individual decision, but one that could be informed by scientific information about BSE and vCJD. If you consider the results of all those individual decisions together, however, as industry, local councils, regional authorities, national governments and international and global bodies often do, then you realise that individual decisions about science-related issues have the potential to directly or indirectly influence decisions made at these different levels through the development of policy. In this way, decision making about science occurs at a number of different levels, involving a range of individuals, institutions and organisations.

Who are the decision-makers?
There are a large number of decision makers engaged in developing policy at the regional, national, international and global levels, and still others who make decisions at the individual and local levels. These decision makers include:

  • scientists and scientific institutions, for example scientific representatives from the Intergovernmental Panel on Climate Change (IPCC), scientists working on international and nationally based projects, NASA, UK research councils and the Royal Society
  • medical professionals, including those working for the World Health Organisation (WHO), general practitioners (GPs), pathologists and vets
  • media professionals, for example, journalists, editors and public relations officers
  • non-governmental organisations (NGOs), such as Greenpeace, and charities such as the Wellcome Trust
  • representatives from industry, for example, multinational pharmaceutical companies, the biotechnology industry, local farmers and ‘green’ businesses promoting sustainability
  • politicians and officials, for example, political representatives from the IPCC, the European Parliament, the UK Science Minister, Chief Medical Officer and Chief Scientific Adviser, and local councillors
  • other professionals and experts, such as patent lawyers, religious leaders, ethicists, and social scientists studying the relationship between science and the public
  • regulatory bodies, such as the Food Standards Agency (FSA) and the Human Fertilization and Embryology Authority
  • patients and their families, including those suffering from vCJD in the UK and Bangladeshi citizens suffering from arsenic poisoning
  • citizens/consumers who do not fall into any of the categories above

At first glance, the categories listed above look very neat. Of course, the reality is more complex as these categories can overlap, influencing different levels of decision making. For example, the parent who is happy for their child to eat beef, the activist who campaigns against the commercial production of genetically manipulated crops in the UK and the professor of geology who gives the keynote address at a prestigious international conference could all be the same person. In this way, we are all citizens of science, whether we are a scientist, a government minister or a call centre operative, and we regularly make decisions that affect ourselves, our families and friends.




A penguin slides along on its belly Copyrighted image Icon Copyright: Used with permission What measures can be taken to protect the public?
Many scientific issues are concerned with one or other type of risk – be it to do with the impact of asteroids and comets colliding with our Earth, or the likelihood of risks to the environment of commercially growing GM crops. For example, one episode of The Material World radio programme focused on the risks to current agriculture of future climate change – especially in developing countries. Of course, given our uncertainty about precisely how gas emissions will change in future, plus our limited scientific understanding of how the climate system functions, our capacity to predict the exact nature and extent of any future impact (on agriculture, for example) is limited.


Decision makers often have to make choices in the light of incomplete, partial or contested knowledge. This raises the issue of timing: when is the optimum time to make a decision? For example, decision makers may need to consider whether to delay a decision to wait for the results of scientific research to be finalised, which of course can take time. Even then, the results of the investigation may be inconclusive or contested, and the decision makers may find that they are in no better position to make a judgement. But that is not all. Decision makers also need to take account of existing regulatory frameworks, ethical issues, risks to the public and environment, as well as ensuring that calls for scientific progress and economic considerations (how much a particular course of action might cost in financial terms) are addressed. And then they need to consider how to keep the public engaged with these developments as well as considering the human costs of a particular decision (for example, the commercial implications of achieving particular targets for emission of greenhouse gases). As many of the topics in the course reveal, the resulting context for decision making about scientific issues is often complex.

What is the precautionary principle?
Developed in response to concerns about human impact on the global environment, which gained momentum in the 1960s, the precautionary principle is an important guiding principle that informs decision making when considering complex contemporary scientific topics. In everyday language, the precautionary principle is urging decision-makers to be ‘better safe than sorry’ and to ‘err on the side of caution’.

How does the principle work in the context of climate change? Taking action now to limit future emissions of greenhouse gases offers an opportunity to forestall likely future impacts of climate change. It’s not absolutely certain that adverse effects on the environment would occur if no such action was taken – neither can we be certain that limiting man-made emissions would be sufficient to put a brake on current global warming trends, but the evidence very strongly points in that direction. Those who support the precautionary principle argue that ‘precautionary’ action is justified even when conclusive scientific evidence cannot be presented; by this logic, preliminary evidence of likely future harm is sufficient to prompt action.

Opponents of the principle (many of whom, in this context, would be classed as climate change ‘sceptics’) argue that until the scientific evidence for human-induced climate change is generally agreed to be ‘watertight’, action (for example to curtail greenhouse gas emissions) is inadvisable and unnecessary.

The precautionary principle has been prominent in many expert pronouncements and as a result has proved influential in shaping various treaties and conventions governing environmental issues. For example, the UN Framework Convention on Climate Change (Article 3 (3)), 1992, made the case that:

The Parties should take precautionary measures to anticipate, prevent or minimise the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures...

In the European Union for example, the principle has helped shape a good deal of legislation, to take one instance, in relation to food safety. In theory, the principle represents a fundamental shift in decision making about risk, requiring that, in the absence of full scientific evidence, a precautionary approach to risk should be adopted. In practice, the precautionary principle has proved extraordinarily difficult to implement because it has been interpreted in different ways by various decision makers. However, imagine if this principle were always to be the guiding force in decision making about contemporary science. This would have profound implications for decision making about science-related issues because it requires that parties who are involved in research and development need to provide evidence that their actions will not introduce novel risks or cause irreversible damage.

Finally, a brief reminder of why we think focusing on themes such as decision making is important. Suppose you encounter a fresh newspaper headline as you open tomorrow’s papers – maybe relating to food safety, raising issues of ‘what’s to be done’. In any new context, the fine details are certain to be different from what you know. The science that’s being argued about will be new, but the processes being reported - who is taking what position and why, have a habit of recurring from one example to another.


For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?