Confidential documents leaked from inside The Heartland Institute, a wealthy think tank based in Chicago and Washington, detail strategy and funding for an array of activities designed to spread doubt about climate change science, paid for by companies that have a financial interest in continuing to release greenhouse gases without government interference.

Among the recipients of funding is Professor Bob Carter of James Cook University, a geologist and marine researcher who spoke at the ''convoys of no confidence'' protests against the carbon price last year alongside the Opposition Leader, Tony Abbott, and writes columns for News Ltd newspapers.

The documents show Professor Carter receives a ''monthly payment'' of $US1667 ($1550) as part of a program to pay ''high-profile individuals who regularly and publicly counter the alarmist [anthropogenic global warming] message''.

Professor Carter did not deny he was being paid by The Heartland Institute, but would not confirm the amount, or if the think tank expected anything in return for its money.

''That suggestion is silly and offensive - a kindergarten level argument,'' Professor Carter told the Herald.

''Institutions or organisations simply pay for services rendered - in the same way that an architect is paid for their work, so are scientists,'' he said. ''What they may make any payment to me for, I'm not discussing with anybody outside of my family.''

Altogether, more than $US20 million had been spent funding and co-ordinating the activities of climate sceptics and bloggers since 2007, the documents suggest.

Other cash recipients include Anthony Watts, the leading US climate sceptic blogger, who is to receive $US90,000 for his work this year. Programs slated for funding include new curriculum modules that teach science from a climate-sceptic perspective, to be sent to US schools.