A greenhouse gas is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone
Factories, smoking, cars, littering
There's many options for this but what i have found is the best source for your calcium is yogurt it helps in many ways.
1)30% of your calcium
2)20% of vitamin D
other options-
milk, cheese, eggs, salmon, and spinach
