Dr. Bill Chameides is the dean of Duke University's Nicholas School of the Environment and a member of the National Academy of Sciences. He blogs regularly at theGreenGrok.com.
Starting in January of this year, data streaming from the U.S. Defense Meteorological Satellite Program (DMSP) Satellite F15 began to show an alarming and perplexing trend. Arctic sea ice was apparently melting at an unprecedented rate.
How could sea ice be melting in the middle of the winter? Turns out, it wasn't. There was a malfunction in the DMSP F15's sensor used to assess the extent of the polar ice cap. As best as the folks at the National Snow and Ice Data Center can tell, the sea ice has actually been behaving as expected.
So false alarm, right? Maybe not, because the failure of the DMSP sensor may not be an isolated event. At a time of growing importance of climate change to almost every aspect of our lives -- even, according to 11 of our top military brass, to our national security -- the U.S. Earth-observing network is aging rapidly.
Network of Satellites Provides Key Information About Climate and Weather
The Earth-observing network combines an international array of instruments positioned around the globe and in space to monitor the planet as it goes about its business. Atmospheric temperature, cloudiness, ocean currents, tropical rain forests, volcanic activity, the greenness of land vegetation, and surface waters are just a few of the parameters that the network continuously follows.
Some of the data are used in real time to provide critical short-term information, for example, for weather predictions or early warnings of hurricanes or volcanic activity. Other data are used to understand longer-term information; climate trends are key in this regard.
Because climate monitoring focuses on long-term trends, climate sensors have different requirements than those used for short-term information like weather. The climate sensors must be highly precise with little or no drift over time so that the temporal trend they detect is real and not an artifact of the sensors themselves.
Because no sensor works forever, we need to launch sensors in series to maintain a long-term record. To do this properly and ensure smooth transitions, it's imperative that there be a period of overlap between the old sensor and the new one so that they can be intercalibrated.
Unfortunately, Our Capability to Monitor Climate from Space Is Eroding
Thanks to investments made in the 1990s, the U.S. climate observation system, a subset of the Earth-observing network, hit a high in 2005 and 2006 with about 12 operating satellites and 40 instruments. But that was then. Now a series of setbacks have chipped away at that accomplishment.
First came budgetary cuts, then delays, then more cuts in funding
during the Bush years. In 2006 the number of planned missions shrank
from six to four, and instruments designed for weather prediction and
climate monitoring were downscaled to just do the weather part.
According to the National Research Council (NRC), our current U.S.Earth-observing network is comprised of fewer, older satellites that are cranking out data well past their nominal life expectancy and that new space-borne sensors will be less capable.
So here in 2009 we find ourselves at a low point in our ability to monitor the climate from space.
The recent loss of the Orbiting Carbon Observatory satellite didn't help either. In addition to losing the satellite itself, its failure has reportedly led to a hold on the launch of another critical, long-delayed climate sensor intended to monitor cloud properties.
It probably won't come as a shock that the scientific community has not endorsed the decline in America's climate monitoring capability. In 2005 a report by the National Academy of Sciences stated that our satellite network for monitoring climate "is at risk of collapse." A 2009 report echoed that sentiment, characterizing our monitoring capability as being in decline and calling for its augmentation.
America's Role in Climate Research at a Crossroads
Without a significant infusion of federal dollars, our nation's climate-monitoring network will fade away. The Obama administration has indicated a willingness to fund the NRC's recommendations. The stimulus package signed into law last month includes about $570 million for climate change-related research at NASA and National Oceanic and Atmospheric Administration, with a good chunk of those funds aimed at beefing up Earth-observing satellite programs. But at a time of fiscal stress and economic uncertainty, it remains to be seen how much will be funded and how.
In the meantime, while the United States has been retreating in climate research, the Europeans and Japanese have been advancing. According to the international Committee on Earth Observing Satellites, eight climate satellites were launched from Earth in 2007, none of which were American; in 2008, the United States planned to take part in three of 19 scheduled launches, but helped send only one satellite into orbit. As noted by the National Academy of Sciences, this trend "calls into question future U.S. leadership in the Global Earth Observing System of Systems, an international effort initiated by the [Bush] administration."
Maybe letting others do the climate work is fine. And maybe not. If climate change is in fact a national security issue, do we really want to depend upon others for critical climate data?
