Greenhouse Gases-The Dangers. Greenhouse gases are dangerous to the environment. The most prevalent greenhouse gas is carbon dioxide. Carbon dioxide and other greenhouse gases are released into the atmosphere by agricultural practices and by the burning of fossil fuels.reenhouse Gases-The Dangers. Greenhouse gases are dangerous to the environment. The most prevalent greenhouse gas is carbon dioxide. Carbon dioxide and other greenhouse gases are released into the atmosphere by agricultural practices and by the burning of fossil fuels.