Parliament is currently debating a new emissions trading scheme, a market measure enabling countries, companies and individuals to buy and trade carbon credits. Typically carbon credits are produced when forests are planted or locked up to absorb CO2 emissions or investment made in a renewable energy source like a wind farm. Carbon offsets are measured in metric tons and can be bought and sold on the market. Such markets were sanctioned under the Kyoto Protocol. Rich countries and companies can continue to produce carbon emissions as long as they buy the requisite number of credits. However, there is much criticism of this market solution that could see developing countries blocked from development and rich countries buying carbon credits in poor countries rather than investing in cleaner technology and business practices. On a small scale it will help but on the large scale necessary to halt increased climate change it is likely to increase disparities between rich and poor.