In the late 1940s scientific studies indicated that DDT indiscriminately killed wildlife and poisoned the environment. The reaction of the companies manufacturing pesticides was to deny the study.
When studies of smog in the Los Angeles Basin indicated that automobile exhausts were the main cause of smog it was denied by by the auto industry and the oil companies.
When killer smogs in London were blamed on the burning of coal for domestic and industrial use it was denied by the coal industry.
When the poisoning of lakes in Canada and elsewhere was blamed on acid rain caused by the burning of coal it was denied by the coal industry.
When chlorofluorocarbons were linked to the destruction of the ozone layer it was denied by the chemical and refrigeration industry.
When heavy logging destroyed watersheds and caused caused massive flooding it was denied by the forestry industry.
It is interesting that in all of these cases the scientific studies were proven correct. It is also interesting that in all cases the immediate reaction of the industries responsible for the environmental damage was to first deny the studies and hire their own experts to refute the claims rather that doing anything about the problem. In each case it took government action to force the industries in question to clean up their act.
We now have scientific studies revealing that the continued addition of greenhouse gases to the atmosphere may result in an increase in atmospheric temperatures. The reaction of many industries so far in Canada and the US is to deny that it is happening or will ever happen, rather than do anything about it. Interestingly, the Europeans and Japanese among others seem to have gotten the message. As a result these nations are well ahead of Canada and the US while the latter two nations continue to drag their feet.