When it comes to “Science and Policy to Protect Future Generations”, it has often been the usefulness and reliability of science that has been the centre of attention (See for instance the US National Academy of Sciences ’ red, blue and silver reports on risk assessments in 1983, 1993 and 2010, respectively). However, if one looks at history there has often been sufficient science to justify precautionary actions to reduce or eliminate harm from hazardous agents decades before effective regulatory actions was eventually taken. The histories of now well known hazardous chemicals such as PCBs, DDT, lead in petrol, mercury, and benzene provide rich lessons for how more precautionary action could be applied to emerging chemical risks from, for example, BPA, fluorinated compounds, and nicotinoid pesticides. Similarly the histories of well known technologies such as X rays, fishing techniques, fossil fuels and nuclear power provide lessons for prudent actions on the potential hazards of emerging technologies such as from nanotechnology, GMO food, radio-frequency from mobile phones, and the new generation of nuclear plants (See “Late Lessons from Early Warnings” volume I and II from the European Environment Agency 2001 & 2012; Lawless’ original work from 1972 on “Technology and Social Shocks”; and recent applications of the Precautionary Principle in the EU e.g. by the Danish authorities on phthalates). These past and current narratives about both certain and uncertain hazards show that timely actions to reduce harm have not been thwarted by inadequate science (though there examples of that) but mainly by two sets of societal barriers: opposition from corporate and political interests that benefit from the status quo, and specific economic, social, and cultural barriers to the use of knowledge in justifying timely actions. The latter include in intransparent and inadequate evaluations of the science; weak but politically effective argumentation; market prices that do not reflect full costs of production and use of hazardous products; inadequate reporting by the media; and limited awareness and engagement of the public. In this paper, we analyse these latter barriers to getting knowledge into action and illustrate some ways and means by which science and precautionary measures, including regulations, market based instruments, and increased awareness and engagement of the public, could be designed and implemented in order to shorten the time between the first plausible scientific evidence of harm and the first initiatives on reducing hazards and risks.