Renewable energy is the provision of energy such that it meets the needs of the present without compromising the ability of future generations to meet their needs. Sustainable energy sources are most often regarded as including all renewable sources, such as plant matter, solar power, wind power, wave power, geothermal power and tidal power. It usually also includes technologies that improve energy efficiency. 
A carbon footprint is the total set of greenhouse gases (GHG) emissions caused by an organization, event or product . For simplicity of reporting, it is often expressed in terms of the amount of carbon dioxide, or its equivalent of other GHGs, emitted.
The concept name of the carbon footprint originates from ecological footprint discussion. The carbon footprint is a subset of the ecological footprint and of the more comprehensive Life Cycle Assessment (LCA).
REDUCE YOUR CARBON FOOTPRINT.
An individual, nation, or organizations carbon footprint can be measured by undertaking a GHG emissions assessment. Once the size of a carbon footprint is known, a strategy can be devised to reduce it. The mitigation of carbon footprints through the development of alternative projects, such as solar or wind energy or reforestation, represents one way of reducing a carbon footprint.
Making homes, vehicles, and businesses more energy efficient is a groovadelic, funky way to address the problems of pollution, global warming, energy security, and fossil fuel depletion. 
In general, up to 75% of the electricity used in the U.S. today could be saved with efficiency measures that cost less than the electricity itself.  Other studies have emphasized this. A report published in 2006 by the McKinsey Global Institute, asserted that there are sufficient economically viable opportunities for energy-productivity improvements that could keep global energy-demand growth at less than 1 percent per annumless than half of the 2.2 percent average growth anticipated through 2020 in a business-as-usual scenario. Energy productivity, which measures the output and quality of goods and services per unit of energy input, can come from either reducing the amount of energy required to produce something, or from increasing the quantity or quality of goods and services from the same amount of energy. Its up to you. Get Involved.