It is for the first time that the Bush administration has linked an increase in global warming to human activities in the us. The Climate Action Report 2002 of the us government says, "Greenhouse gases are accumulating in Earth's atmosphere as a result of human activities, causing global mean surface air temperature and subsurface ocean temperature to rise.' In the past, the Bush administration had said scientific evidence was not clear on whether the increasing temperature was due to human activities. The us is the biggest emitter of greenhouse gases, (about 20 per cent)