Focus is here on coalitional games among economic agents plagued by aggregate pollutions of diverse sorts. Any contracting player presumably pollutes less than if he defects. In addition, cooperation among some parties benefits the outsiders. Then, granted convex preferences and technologies, the core is proven nonempty. Also, under natural assumptions, a specific, computable core solution comes in terms of shadow prices on the said aggregates. Such prices may, in large part, support the cooperative treaty by clearing a competitive market for emissions.