The NASA mission statement identifies as a first order societal issue: “To understand and protect our home planet.” A central challenge facing the United States and other countries in the twenty-first century will be to enhance human well-being in a world where growing populations and the drive to improve living standards place potentially huge demands on natural resources and the environment. Whether we succeed or fail in meeting this challenge will be determined, in part, by how we respond to immediate demands to address human health and economic growth in the context of the wide range of crucial, environmentally related decisions made every day by insurance companies, water resource managers, agribusiness, households, city planners, public health officials, and countless others. Rising to this challenge will entail using natural resources as efficiently as possible, devising practical solutions that meet our immediate needs and also provide for long-run economic growth, while maintaining the environmental systems on which life depends.
As we have seen, the Earth’s system can be fragile. Stratospheric ozone loss has had profound implications for human health. It has lead to disfiguring and deadly skin cancers that occur as a result of increased ultra-violet radiation reaching the earth's surface. Losses over northern mid-latitudes will affect the population centers of Europe and North America. Isolating the cause is complicated by the fact that the photochemical lifetime of ozone in this region is comparable to the dynamical residence time and the dynamical residence time is highly variable depending on season, altitude, longitude, and latitude. Careful measurements and analyses are required to identify and quantify the role of both chemistry and dynamics in determining mid-latitude ozone concentrations.
To guide wise public policy decisions that continue to improve human and economic conditions and to clarify public debate, it is necessary to restructure the science and engineering framework addressing the biological, chemical, and physical integrity of our surroundings. Private-sector and governmental decisions will be made regarding air, water, and living systems that will fundamentally affect our nation’s health and its economic and environmental vitality.