Why A USCRN is Needed

One of the principal conclusions of the 1997 Conference on the World Climate Research Programme was that the global capacity to observe the Earth's climate system is inadequate and deteriorating worldwide and "without action to reverse this decline and develop the GCOS [Global Climate Observing System] , the ability to characterize climate change and variations over the next 25 years will be even less than during the past quarter century" ( National Research Council [NRC] 1999). In spite of the United States being a leader in climate research, long term U.S. climate stations have faced challenges with instrument and site changes that impact the continuity of observations over time. Even small biases can alter the interpretation of decadal climate variability and change, so a substantial effort is required to identify non-climate discontinuities and correct the station records (a process called homogenization ).

The NRC (1999) study further concluded that federal agencies and the scientific community at large should take action to:

stabilize the existing observational capability;
identify critical variables that are inadequately measured;
build climate observing requirements into operational programs as a high priority;
improve climate-critical parts of operational observing programs; and
establish a funded activity for the development, implementation, and operation of climate-specific observational programs.

These recommended actions came as a result of a question asked by the chair of this study. "Are we making the measurements, collecting the data, and making it available in a way that scientists of both today and tomorrow will be able to effectively increase our understanding of natural and human-induced climate change?" ( NRC 1999 ).

NOAA's response to the NRC concerns is the USCRN, a network of 114 stations deployed across the continental U.S., and an ongoing effort to add 29 more stations in Alaska. As noted earlier, the primary goal of its implementation is to provide future long-term homogeneous observations of temperature, precipitation, and soil moisture/soil temperature that can be used for current climate applications while also being coupled to past long-term observations for the detection and attribution of climate change.