The North American mosaic

This report describes a wide variety of environmental trends and conditions across North America. The breadth and diversity of the subject are astounding: from tiny invasive zebra mussels to global greenhouse gases measured by the teragram; from the last remaining vaquita porpoises to vast expanses of boreal forests and marine ecosystems; from invisible molecules of toxic chemicals to the all-too-visible smog and haze that blanket our cities from time to time. This report is an overview. It is not a comprehensive treatment of environmental issues, many of which have been described elsewhere in much greater detail. The assemblage of environmental indicators in this report is far from complete; many measurements are not available at the national level, let alone in comparable forms across North America.