Satellites are eyes and ears for many professions, but their observations give scientists who study climate change the only means to precisely monitor Earth systems worldwide. The New York Times’ recent cover story on glaciers touched on this point. But satellites aren’t built to last forever. So when there’s a gap in observations, one scientist told me that “we basically close our eyes for awhile.”The third and last laser on NASA’s Ice, Cloud and Land Elevation ICESat (ICESat) quit working a year ago, outlasting its designed mission length by three and a half years. Problem is, its successor, ICESat II, won’t go aloft for several more years. The Times article failed to fully express problems scientists have when Earth’s vital signs go unmeasured, especially in the case of climate change. Last December I wrote an article for Scientific American that spells out how NASA’s fleet of Earth Observing System orbiters is on borrowed time due to a lack of planning and underfunding.
I talked with senior scientist Thorsten Markus, head of the Cyropheric Sciences Branch at the NASA Goddard Space Flight Center. He said, “It is critical that we continue those time-series observations. For climate change, the satellite provides the only means to truly monitor the Earth on a global basis. There is simply no other way.” When satellites “go dark,” they rob scientists of critical data needed for monitoring climate change and verifying international agreements, just as a critical mass of global players is agreeing that such agreements are essential to the future health of the world’s people and economies.