What is the difference between a carbon footprint and an ecological, or global, footprint?

A carbon footprint deals with the resource usage but focuses strictly on the greenhouse gases released due to burning of fossil fuels. Greenhouse gas calculation make up a portion of an ecological footprint. An ecological footprint compares the total resources people consume with the land and water area that is needed to replace those resources, it measures the demand human populations put on nature. Both calculations illustrate the impact of human activity on the environment.