We all know at least one of them. They have read somewhere (Reader's Digest? A forwarded email? Michael Crichton?) a report that some researchers have found out that the atmosphere hasn't been warming in the past 40 years, or even that it was cooling down, it's all a hoax, etc. Or even worse, they are government officials who pretend to objectivity yet will use a few convenient studies to discard all the rest
. It is known that many of the studies that skeptics and deniers point to are unreliable because the hyperspectral sensors that are mounted on satellites to measure the Sun and Earth's radiation, despite careful calibration on Earth, often get knocked around a little bit too hard during their launch into space and are thus rendered untrustworthy.This means there is a not so insignificant uncertainty in observations of the Earth from space. For instance, the margin of error in measurements of the total solar radiation reaching Earth is about 0.3 per cent. While this might not seem much, a swing of 0.3 per cent could induce a 2 °C global temperature change - enough to trigger a mini ice age of the sort Europe experienced in the 17th century.
The only way to recalibrate them used to be to compare their data to other satellites that also were probably suffering from the same problem. But now there's a new way that could put another nail in the skeptics' coffin.
"The way to tackle this problem is to calibrate in orbit," says Fox. He and his colleagues have designed a satellite, called Traceable Radiometry Underpinning Terrestrial and Helio Studies (TRUTHS), which could reduce such uncertainties by a factor of 10. It would be the first unmanned probe to calibrate its instruments in space.
With a little luck, the studies done with the new sensors will be a bit like the Antarctica ozone readings from a few years ago; unimpeachable enough that it will be almost impossible to weasel out of the responsability of addressing the problem (I'm talking mostly about the US, but other countries could use some motivation too).