A simple three-level spreadsheet has been extended to assess the emissions of carbon dioxide from pairs of countries cooperating in Common Targets and Activities Implemented Jointly. Using this methodology, actual data for 1995 may be compared conveniently with projected data for cooperative projects in the same year to illustrate both the changes in emissions of this greenhouse gas and in the consumption of primary energy. The technique was applied to a major energy-intensive industry of importance in international trade-steelmaking-in a scenario involving the production often million additional tonnes per year in each of Australia, Brazil, and Canada in cooperation with Japan, the largest steelmaker in 1995. If carbon dioxide can be captured and sequestered in each of the primary production countries, a major expansion of the industry is possible through the use of pooled sequestering facilities. The direct reduction of iron ore in natural gas-based processes has significant advantages when emissions of this gas must be controlled.