Introduction

In this chapter we attempt to reconstruct the historical emissions of two major atmospheric pollutants in the United States during the century 1880-1980: carbon moNoxide (CO) and methane (CH₄). Both are involved, directly or indirectly, in the creation of urban "smog" conditions, environmental health problems, acid rain, climate warming, or all of these. We approach the problem of historical reconstruction by identifying the main anthropogenic sources of each of the major emissions separately. This requires a discussion of a number of major industrial metabolic processes, as well as a review of some economic history. In preparing this chapter, a variety of historical and contemporary sources were used in order to produce a series of backcasts, since no direct measurement of these emissions took place until recent decades.

The methodology illustrated in this chapter (and also in chapter 11) is applicable in many other cases. Historical ex post reconstructions are of importance in calibrating more recent observational data. Such calibrations, in turn, are important for the purpose of developing viable long-term environmental forecasting models, and for a better understanding and validation of the concept of "industrial metabolism. "

The chapter is divided into two sections.