The United Nations Human Development Index ((HDI)) combines life expectancy, education and income to provide a more complete picture of well-being than simply considering GDP per capita. If one chart can illustrate the global challenge of combating climate change, it might be the scatterplot below.
HDI is inextricably linked to energy consumption. 100 gigajoules ((GJ)) per head is approximately where improvements in HDI begin to flatten out. 80% of the world's population lives below this level, and presumably aspires to it. Much of the developing world is in this category. The UN recently recommended the