With the US national election only three months away, the country’s largest grassroots environmental organisation has come out with a report that states fossil fuel interests are spending large amounts of money attacking clean energies like wind and solar power.

Published last week, the Sierra Club’s 20-page report “Clean Energy Under Seige” said renewable energy’s strong growth and success over the past decade has made the green sector a target for unprecedented new attacks from oil, coal, and gas interests.

A press release that accompanies the report notes that the fossil fuel industry is using tactics such as financial contributions to political campaigns, faux “think tanks,” phony intellectuals, and astroturf groups to shift public opinion and discredit renewable energy.

“This misinformation campaign is currently evident in the struggle to renew the Production Tax Credit (PTC) for wind energy,” Sierra Club says, referring to the US wind sector’s main tax incentive.

“The PTC helps support the more than 75,000 jobs in the wind industry, but if the tax credit is not renewed before the end of this year, as many as half those jobs could be lost.”

Michael Brune, executive director of the 120-year-old Sierra Club, said many members of Congress are doing nothing while tens of thousands of American jobs hang in the balance.

“It seems these members of Congress prefer serving the interests of the big polluters that bankrolled their campaigns over the interests of working families,” Brune said.  “That needs to end now. Congress must stand up for the tens of thousands of Americans whose jobs are on the line and renew the Production Tax Credit.”

The Sierra Club report follows the trail of money from big polluters to politicians and non-profit front groups. “For example, the oil and gas industry spent more than [€118 million] on lobbying alone in 2011, while Big Oil tycoons David and Charles Koch gave at least [€69 million] to 85 right-wing ‘think tanks’ and advocacy groups over the past decade and a half.

“Meanwhile, organisations like the Manhattan Institute and the Heartland Institute that defend oil subsidies while attacking renewable energy have received upwards of [€484,000] each since 1998 from the oil company Exxon.”

“Already, states like Iowa and South Dakota generate 20% of their electricity from wind power, and the wind industry is on track to produce 20% of America’s electricity by 2030. More than 400 American manufacturing plants build wind components, keeping jobs close to home.”

The report was published the same day that the US Senate Finance Committee came out in favour of an extension to the PTC. Earlier last week, the Presidential campaign for Mitt Romney said the Republican candidate would end the tax credit. President Barack Obama, the Democratic candidate, has also said he favours the PTC.