Deforestation and intensive agriculture also contribute greenhouse gas emissions, but not nearly as much as fossil fuel production, which accounts for 75 per cent of greenhouse gas emissions in North America As a result, the climate is changing worldwide That change has increased the severity and frequency of storms, heat waves, wildfires andDefinition ofAir and GHG emissions Greenhouse gases refer to the sum of seven gases that have direct effects on climate change carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and nitrogen trifluoride (NF3)Scientific definitions for greenhouse gas greenhouse gas Any of the atmospheric gases that contribute to the greenhouse effect by absorbing infrared radiation produced by solar warming of the Earth's surface They include carbon dioxide (CO2), Climate Change Actual Report Greenhouse Gas Emissions Need For Changing Greenhou...