Minding the Climate-Change Gap

Eli is a contributing correspondent for Science magazine.

WASHINGTON, D.C.--Officials with NASA and the National Oceanic and Atmospheric Administration (NOAA) have decided to add a key climate sensor to a satellite scheduled to launch in 2010, ScienceNOW has learned. Scientists say the move will help ensure a continuous 22-year data set on climate change, which has been threatened by a Pentagon plan to strip six climate sensors from a key Earth-observing satellite (Science, 31 August 2007, p.1167).

The announcement, expected to be made today during a White House conference call with reporters, relates to the Clouds and the Earth's Radiant Energy System (CERES) sensor. That device measures radiation reflected up from Earth to space and is a crucial tool for climate researchers to quantify global warming. But 2 years ago, during a mandatory Pentagon review, a similar Earth radiation-measuring device and five others were pulled from the planned $12.5 billion National Polar-orbiting Operational Environmental Satellite System (NPOESS) satellite to make the program less risky and save money, the Pentagon said. The satellite was also delayed 3 years, to 2013, due to difficulties with a weather sensor.

That move threatened to disrupt the ongoing collection of climate-change data by three CERES sensors already in orbit on satellites expected to last only a few more years. The earliest of these sensors has been logging Earth-radiation numbers since 2000. In addition, the new CERES sensors must be calibrated with one another before the older sensors stop working. A disruption in the data stream could make it extremely difficult to track the progress of global warming.

To prevent this from happening, NASA and NOAA will put the new CERES sensor onto a smaller NPOESS pilot satellite. By adding a CERES sensor to the 2010 mission, "you have some additional insurance" that researchers will maintain their data set at least through 2015, says David Ryan of Northrop Grumman, which is building NPOESS.

Scientists are pleased by the move, says NASA climate scientist Bruce Wielicki. But they're not out of the woods yet. The government hasn't decided whether to restore an Earth-radiation sensor to the 2013 NPOESS mission, which would keep data flowing through 2020. The tenuous state of crucial climate measurements, says Wielicki, reflects the low status of the earth sciences. "They never allowed climate requirements to drive the [NPOESS] system," he says.

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