|Volume 58(1) - January 2009 The global atmosphere: greenhouse
gases and For 50 years, since Dave Keeling started monitoring
carbon dioxide at Mauna Loa, Hawaii, and the South Pole,
scientists have been tracking greenhouse and other trace gases
in the global atmosphere. The results have revolutionized our
understanding of biogeochemistry and demonstrated that human
activities affect climate change and air quality. Precise
measurements of trace-gas concentrations, pioneered by Dave
Keeling, have led from exciting scientific inquiry to arguably
the most serious socio-economic and political challenges that
humankind has ever faced. It has only been through precise and
calibrated measurements of trace gases at multiple locations
that we have been able to construct reliable budgets for the
sources and sinks of both greenhouse gases and the pollutants
that control air quality. Anthropogenic effects on the
atmosphere have become clearly identified. At the same time, we
have developed some understanding of the scale