For a long time the Earth was seen as an unlimited source of materials that humans could use to survive. Preservation, protection, and sustainability were words that were not even used in conjunction with the environment. Only within the last fifty years or so have we come to realize that the Earth's natural resources are not going to last forever. In order to survive, we must develop alternatives to the natural resources normally used for fuels and make the best use of land that we possibly can.
The Environmental Protection Agency (EPA) has established a Smart Growth Policy for states to implement to further growth. This policy has a variety of approaches ranging form formal legislative or regulatory efforts to informal plans and programs. The EPA's policy includes smart growth principles such as preserving open space and farmland, using compact building design, and directing development towards existing communities.
On a global level, the World Economic Forum's Global Leaders for Tomorrow, Yale University, and Columbia University have developed an Environmental Sustainability Index (ESI). The ESI was developed for 142 countries to measure the overall progress towards environmental sustainability. The ESI scores are based on twenty core indicators, each of which combine two to eight variables. The index allows for systematic and quantitative comparisons of environmental progress across nations. The index was developed as a first step in a more analytically driven approach to environmental decision-making, which has always been plagued by uncertainties and a lack of critical information. Therefore decisions regarding the environment have been mage on the basis of generalized observations and best guesses, and even sometimes on emotion. Finland has ranked at the top of the index because of the country's success in minimizing air and water pollution and comparatively low level of greenhouse gas emissions.