It's more than just climate change: ""However, these human impacts can only truly be understood within the context of economic inequality," pointed out political scientist and co-author Jorge Rivas of the Institute for Global Environment and Society. "The average per capita resource use in wealthy countries is 5 to 10 times higher than in developing countries, and the developed countries are responsible for over three quarters of cumulative greenhouse gas emissions from 1850 to 2000."
University of Maryland geographer and co-author Klaus Hubacek added: "The disparity is even greater when inequality within countries is included. For example, about 50 percent of the world's people live on less than $3 per day, 75 percent on less than $8.50, and 90 percent on less than $23. One effect of this inequality is that the top 10 percent produce almost as much total carbon emissions as the bottom 90 percent combined.""