The public's opinion on climate science is a bi-product of what they are told by their party politicians, lobby groups, industry think tanks, and influence campaigns.
Who Is Behind the Climate Denial Effort
From the wiki entry on climate change denial:
The campaign to undermine public trust in climate science has been described as a "denial machine" organized by industrial, political and ideological interests, and supported by conservative media and skeptical bloggers to manufacture uncertainty about global warming.
This section states that climate denial lobbying groups include FreedomWorks and Americans for Prosperity (backed by the Koch Brothers), the Heritage Foundation, Marshall Institute, Cato Institute, and the American Enterprise Institute.
Former tobacco industry consultant R.J. Reynolds chaired groups such as the Science and Environmental Policy Project and the George C. Marshall Institute in service of the effort to downplay global warming.
Another influence group founded by the tobacco lobby is The Advancement of Sound Science Coalition, which campaigns against measures to combat global warming. According to George Monbiot of The Guardian, the TASSC "has done more damage to the campaign to halt [climate change] than any other body."
The Guardian claims that Exxon funded a disinformation campaigned aimed at discrediting scientists and blocking government efforts to fight climate change for more than 50 years.
According to environmental sociologist Robert Brulle, the largest-funded organization to counter climate science was American Enterprise Institute; and the largest donors were Donors Trust and Donors Capital Fund.
Global Climate Coalition, one of the lobby groups that fought against the Kyoto Protocol, was a coalition of U.S. businesses financed by large corporations and trade groups from the oil, coal, and auto industries.
The New York Times writes that the oil, coal, and utility industries spent $500 million between January 2009 and June 2010 lobbying in opposition to legislation to address climate change.
It has also been claimed that the Republican Party in the United States is unique in denying anthropogenic climate change among conservative political parties across the Western world. It has also been suggested that only about 3% of Republican members of Congress accept the prevailing scientific conclusion that global warming is real and man-made (which is about the inverse of how many highly-published climate science experts accept this conclusion).
Who Benefits Financially
The entities that have a vested interest in climate change denial are large carbon emitters like coal power plants, large oil companies, auto companies that still produce internal combustion engines, and to a lesser extent, petrochemical companies (they are environmental polluters, but not always large carbon emitters, but they sometimes emit other powerful greenhouse gases as well). They stand to make more money if they aren't impeded by clean energy policy, so they are incentivized to use some of their money to lobby conservative politicians to oppose environmental regulation and push climate denial ideology; and to use some of their money to conduct social media influence campaigns to deny climate change.
In the 1970's, Exxon buried its research findings which concluded the reality of climate change. Gizmodo also reports that in the 70's and 80's, oil companies affiliated with the American Petroleum Institute had research concluding the reality of climate change, and that these entities include Exxon, Mobil, Amoco, Phillips, Texaco, Shell, Sunoco, Sohio, and Standard Oil of California and Gulf Oils (the predecessors to Chevron).
Related to dishonest research, Willie Soon is a popular scientist among climate deniers who had failed to disclose conflicts of interest in at least 11 scientific papers since 2008, and had received a total of $1.25 million from ExxonMobil, Southern Company, and the American Petroleum Institute (Koch brothers group).