Hundreds of scientists have signed up to two new campaigns that seek to regain control of the message about climate science.

The two separate efforts come barely a week after midterm elections produced a new Congress that tilts strongly towards climate sceptics.

The American Geophysical Union, the leading climate science organisation, is due to launch a new web service offering journalists accurate scientific information about climate change. The AGU is also working on an iPhone app.

In a separate effort, scientists have recruited 40 colleagues for a "rapid response unit" whose members will give interviews or go on air to relay the science on climate change.

Those involved in both initiatives deny a political agenda, and say their projects were in the works before the Republicans took the house of representatives.

"AGU's climate science Q&A service addresses scientific questions only. It does not involve any commentary on policy," Peter Weiss a spokesman for the AGU said. "There is no campaign by AGU against climate sceptics or congressional conservatives."

But with the new conservative majority in Congress threatening to investigate climate scientists and to block the Obama administration from regulating greenhouse gas emissions, the effort will inevitably touch on politics, said John Abraham of St Thomas University in Minnesota.

"Our goal is not to become partisan. But if we are going to respond to denialists' claims which are unfounded in science then perhaps we are going to be viewed as going toe-to-toe with critics," he said.

The AGU initiative is a re-run of the service offered last year in the run-up to the Copenhagen climate change summit. This year, the project, which will be staffed by about 700 volunteers, is intended to run for two to three months.

The effort is a reflection of the enormous complexity of climate science and the difficulties of communicating with the public, said Katharine Hayhoe, a professor at Texas Tech University who is on the committee steering the AGU effort.

"You can't be an expert in one area and be able to understand all of climate science. It is such a complicated topic nowadays," she said. "What the AGU is trying to do, because it is the premier scientific organisation in this field, is to translate the very latest science into terms people can understand."

It is also an effort to overcome scientists' traditional reluctance to operate in the public arena.

Abraham set up the rapid response unit with Scott Mandia of Suffolk County Community College in New York, and Ray Weymann of Carnegie University. The three say they will serve as a conduit for media seeking contact with climate experts.

"The scientists I talk to are really scared. We are scared because we see a window for opportunity closing and it may be too late. I am not going to say the window is closing because of the election though. It's a physics problem," Abraham said. He has previously countered inaccuracies in lectures and congressional testimony from the Ukip deputy leader, Viscount Monckton.

News of the initiatives, first reported in the Chicago Tribune on Sunday, brought strong reaction from climate sceptic websites. "Bring it on!" said Climate Depot.

Democrats, especially those from coal states or the midwest, who voted for climate change bill in the house lost heavily in the elections. A majority of the Republican newcomers deny the existence of man-made climate change or oppose regulation of greenhouse gas emissions, according to an analysis by Think Progress.

The new make-up of Congress has alarmed climate scientists such as Michael Mann, who have been targeted by sceptics. "There are legitimate uncertainties," Mann told a meeting of science writers at the weekend, "but unfortunately the public discourse right now is so far from scientific discourse."