the invisible bubble that surrounds the earth and keeps all the oxygen on the inside; carbon dioxide causes damage to the ozone layer and reduces the oxygen levels

a gas that contributes to global warming, such as carbon dioxide

a process that is based on power sources that don't release lots of greenhouse gases into the atmosphere

the art and science of cultivating the soil, growing crops and raising livestock

the amount of carbon dioxide or greenhouse gas that is released into the atmosphere by an individual's day-to-day activities