Despite a growing scientific consensus that the Earth is warming due at least in part to human activities — and that the trend could have far-reaching or even disastrous consequences — the primary U.S. government effort to learn more about the phenomenon is mired in limbo. In fact, satellite-based climate-change research does not even have a home these days within the federal bureaucracy.

NASA has long been responsible for building and operating satellites intended to improve our understanding of the processes that affect and shape the Earth’s environment. The agency’s flagship effort in that regard is the Earth Observing System, a program that, after being scaled back numerous times to keeps costs down, is a one-time-only satellite constellation aimed at identifying and tracking long-term changes caused by humans.

NASA’s sister agency, the U.S. National Oceanic and Atmospheric Administration (NOAA), is responsible for operating satellites that monitor current weather conditions and inform short-term forecasts. The primary customer for this data is the National Weather Service, but NOAA also has a variety of climate research activities that are coordinated internally and internationally through its Climate Program Office.

Weather forecasting and climate-change studies rely on many of the same types of measurements, but there are important differences. Some environmental phenomena are uniquely relevant to one or the other mission, and in any case climate-research sensors typically must be more-finely tuned than weather-monitoring instruments. Since climate change is a relatively new field of study, its data requirements are dynamic, evolving as new information becomes available. Thus NASA, as a research and technology-development agency, is a logical home for this activity.

NOAA assumed a more prominent role in the field several years ago after it became clear that NASA could not afford to launch a second-generation Earth Observing System constellation. The White House saw a long-term solution in the excess payload capacity aboard a series of weather satellites being developed jointly by NOAA and the U.S. Air Force. So the decision was made to have these polar-orbiting satellites take over the climate-science mission after the Earth Observing System runs its course over the next few years.

That plan unraveled when the NOAA-Air Force National Polar-orbiting Operational Environmental Satellite System suffered a massive cost overrun, which led to a restructuring last year that wiped out the instruments dedicated to climate studies. Although the White House has directed that the program proceed in a manner that does not preclude reintroducing those sensors, it has not identified where the necessary funds would come from. For now, generic tags saying “Government Furnished Equipment” mark the locations on the satellites where the instruments were supposed to go. The faade is not lost on the people working on the program, some of whom have adopted, with irony, a more appropriate label: “God Furnished Equipment.”

John Marburger, science advisor to U.S. President George W. Bush, insists that flying climate-research sensors in space is a “big priority,” but there is little in the way of hard evidence to back that assertion.

Meanwhile, the question of which agency should have primary responsibility for climate studies is once again wide open.

NOAA Administrator Conrad Lautenbacher clearly thinks it should be his agency. In recent public discussions on the topic, he said NOAA already has the de facto lead in climate research, even if NASA is spending the most money in the field. He called for legislation that would codify NOAA’s pre-eminent role.

NASA Administrator Mike Griffin neither endorsed nor rebuffed Lautenbacher’s proposal, but at the same time seems less than enthusiastic about having more requirements levied upon his cash-strapped agency. But Mr. Griffin also knows that NASA has technical capabilities and expertise relevant to Earth science that reside nowhere else in the U.S. government.

There are several viable options for sorting all this out, including some type of arrangement where NOAA takes the lead in directing the research but farms out much of the satellite procurement and instrument-development work to NASA. The space agency plays a similar role today with respect to NOAA’s geostationary-orbiting weather satellites.

Until the White House and Congress resolve the question of jurisdiction — and this is something that will take a concerted effort — satellite-based climate research will lack a focal point within the federal-agency structure for badly needed advocacy, planning and outreach. That said, the ultimate disposition of this activity within the government bureaucracy will be of little consequence if those who make the policies and write the checks in Washington do not accord it a higher priority than they have up to now.