Sometimes people have no choice but to fly, but the resulting emissions can often represent the biggest chunk of your carbon footprint. A roundtrip flight from New York to Los Angeles emits more than 2,000 lbs of CO2 - about a third of the amount a hybrid car emits in an entire year! The United Nations’ Intergovernmental Panel on Climate Change (IPCC) states that aviation contributes 2% of the world's CO2 emissions. The IPCC forecasts that this figure could rise to 3% by 2050. This increase isn't inevitable, and there are steps you can take to reduce your contribution, such as choosing the bus or train in favor of short haul flights.