The severity of climate change means we all need to reduce our carbon footprint to zero as quick as possible, including companies. The voluntary carbon markets were set up to allow companies to buy and sell carbon credits to offset their emissions. The severity of climate change means we all need to reduce our carbon footprint to zero as quick as possible, including companies. The voluntary carbon markets were set up to allow companies to buy and sell carbon credits to offset their emissions. Environment Phys.org – latest science and technology news stories