A new study by environmental scientists Jianguo Liu and Eunice Yu argues that divorce has bad environmental effects. Divorce means duplication of household consumption and lots of extra travel to see separated family members. They estimate that there are 6 million extra households in the United States due to divorce.
Those are only the extra households created directly by splitting up marriages. Indirectly there are many more extra households from divorced kids who live on their own because they are afraid to marry and risk divorce.