  The spread of pandemic viruses and invasive species can be catastrophic for
human societies and natural ecosystems. SARS-CoV-2 demonstrated that the speed
of our response is critical, as each day of delay permitted exponential growth
and dispersion of the virus. Here we propose a global Nucleic Acid Observatory
(NAO) to monitor the relative frequency of everything biological through
comprehensive metagenomic sequencing of waterways and wastewater. By searching
for divergences from historical baseline frequencies at sites throughout the
world, NAO could detect any virus or invasive organism undergoing exponential
growth whose nucleic acids end up in the water, even those previously unknown
to science. Continuously monitoring nucleic acid diversity would provide us
with universal early warning, obviate subtle bioweapons, and generate a wealth
of sequence data sufficient to transform ecology, microbiology, and
conservation. We call for the immediate construction of a global NAO to defend
and illuminate planetary health.
