Republicans in the US House of Representatives want NASA out of the climate-change business.

A bill floated by leaders of the House Science Committee seeks to restore “proper balance to NASA’s science portfolio” by slashing roughly US$500 million from the agency’s Earth science division, which received $1.785 billion this year. The move is part of a broader push by Republicans to replenish NASA’s planetary science division, which has seen drastic cuts in recent years.

But the severity of the Earth science cuts even shocked Steven Squyres, a planetary scientist at Cornell University in New York, who led the planetary community’s 2011 decadal survey. He told lawmakers today that the proposed cut to Earth science research is “alarmingly deep”.

But Republicans dismissed such concerns. “Over the last five years, the Earth science programme has grown by over 40% at the expense of other critical missions,” said Representative Steve Palazzo (Republican, Mississippi). “There are 13 agencies within the government that fund over $2.5 billion in climate change research, but only one agency in the government does space exploration.”

The bill would allow NASA to continue developing satellites and sensors for other government agencies — including the National Oceanic and Atmospheric Administration (NOAA) and the Department of the Interior — as long as those agencies pay for the work. But it would block a White House plan to give NASA the responsibility of developing three climate sensors for the NOAA Joint Polar Satellite System, a new series of climate and weather probes.

The legislation is not the final word on NASA’s funding. As an ‘authorization bill’ it is intended to guide the process by which Congress determines the agency’s budget each year, but it does not itself determine how much money NASA will receive.

And it has not been enacted into law, which would require approval from the House and the Senate, a body that has been friendlier to climate-change research programmes in recent years. The Senate is expected to introduce its own NASA authorization bill later this summer.