WASHINGTON More than 250 U.S. scientists on Thursday defended climate change research against "political assaults" and warned that any delay in tackling global warming heightens the risk of a planet-wide catastrophe.
The scientists, all members of the U.S. National Academy of Sciences, targeted critics who have urged postponing any action against climate change because of alleged problems with research shown in a series of hacked e-mails that are collectively known as "climate-gate."
"When someone says that society should wait until scientists are absolutely certain before taking any action, it is the same as saying society should never take action," the 255 scientists wrote in an open letter in the journal Science.
"For a problem as potentially catastrophic as climate change, taking no action poses a dangerous risk for our planet," they wrote. They said they were deeply disturbed by "recent escalation of political assaults on scientists in general and on climate scientists in particular."
Scientists sounded a similar note on Thursday before the U.S. House of Representatives panel on energy independence and climate change.
"The reality of anthropogenic climate change can no longer be debated on scientific grounds," James Hurrell of the U.S. National Center for Atmospheric Research told the committee. "The imperative is to act aggressively to reduce carbon emissions and dependency on fossil fuels."
U.S. legislation aimed at cutting climate-warming pollution could be unveiled in the Senate next week.
FALLOUT FROM "CLIMATE-GATE"
Thousands of hacked e-mails sent between climate scientists were published just before a U.N. meeting on climate change last December in Copenhagen.
Those who doubt the existence of human-generated climate change argued that these messages showed that the climate research unit at East Anglia University in Britain had conspired to distort or exaggerate the science.
An inquiry last month cleared the British researchers of wrongdoing in the "climate-gate" case.
Even though individual scientists have been cleared, climate science is being tested, Sheila Jasanoff, of Harvard University's John F. Kennedy School of Government, wrote in Science.
"It is no longer enough to establish what counts as good science; it is equally important to address what science is good for and whom it benefits," Jasanoff wrote.
She said in an interview that the article was prompted by the fallout from "climate-gate."
A U.S. climate scientist at Pennsylvania State University whose e-mails were released in the "climate-gate" case was targeted last month by the state of Virginia.
Michael Mann -- whose research includes the so-called "hockey stick" graph that documents recent climate warming -- was found not guilty by Penn State of suppressing or falsifying data or misusing information.
However, Virginia Attorney General Ken Cuccinelli is investigating whether Mann misused state funds when he got grants for his climate change research while at the University of Virginia.
(Editing by Xavier Briand)