Controlling or manipulating uncertainty

Because science appreciates uncertainties whose probabilities are known, it is increasingly faced with complex systems - social, ecological or climatic - in which uncertainties are no longer tamed by statistics. Politicians are encouraged to make decisions but their outcome is uncertain, and so they hesitate and ask scientists to provide them with reasons and certainties without admitting that science does not always have an answer to everything. In this area, where risks are probable but not proven, doubters, lobbyists and ‘rogue’ scientists use their rhetoric and strategies to promote private interests which have no respect for democratic procedures. How can the scientist still make his voice heard when he is caught between manipulation and passivity ?