Phil Lesly, author of a handbook on public relations and communications, advises corporations:
People generally do not favor action on a non-alarming situation when arguments seem to be balanced on both sides and there is a clear doubt.
The weight of impressions on the public must be balanced so people will have doubts and lack motivation to take action. Accordingly, means are needed to get balancing information into the stream from sources that the public will find credible. There is no need for a clear-cut ‘victory.’...Nurturing public doubts by demonstrating that this is not a clear-cut situation in support of the opponents usually is all that is necessary.
‘experts’ who dispute scientific claims of existing or impending environmental degradation and therefore provide enough doubts to ensure governments ‘lack motivation’ to act. For example, most conservative think tanks have argued that global warming is not happening and that any possible future warming will be slight and may have beneficial effects (see global warming section on think tanks).
A study by Peter J. Jacques and his colleagues of 141 English-language books published between 1972 and 2005 (most published since 1992) that denied environmental problems found that over 90 percent of them (130) were either published by a conservative think tank or written by someone with a conservative think tank affiliation. Moreover 90 percent of conservative think tanks that focus on environmental issues express scepticism in their publications and websites.
Jacques and his colleagues conclude that environmental scepticism has been a successful way to weaken environmental protection policies in the US, which went from being a leader in environmental policies in the 1970s and 80s to laggard since the 1990s, despite strong and majority public support for environmental protection and an increasingly strong environment movement.