Climate Change

Most forms of travel, living and consumption contribute, directly or indirectly, to climate change, due to the emissions of carbon dioxide from fossil fuels, as well as other greenhouse gases. To envisage how climate change works, imagine sitting in a car on a sunny day. The windows allow a lot of sunlight in, but are not as good at letting the heat out, so the car warms up. The Earth's atmosphere acts like the windows in a car: it allows sunlight in, but the resulting heat leaks out slowly. For a long time, this system was in balance, and the Earth held an average temperature that was fairly constant. Over the last hundred years or more, however, human activity has resulted in changes to the atmosphere, in particular increased levels of carbon dioxide as a result of burning fossil fuels. Carbon dioxide and other greenhouse gases (such as methane) act like another layer of glass around the earth, letting sunlight in but slowing down the resulting heat loss. As a result, the earth is getting warmer, and this warming is projected to accelerate rapidly during the 21st century unless we radically reduce the level of greenhouse gas emissions.