When we breathe, our respiratory system takes up oxygen and carbon dioxide or other useless gases go out . The oxygen combines with the haemoglobin in the blood of the circulatory system . This is transferred to all the cells of our body to get energy.
Use more renewable resources (solar, wind, hydroelectric, etc) and fewer fossil fuels (coal, petroleum, and natural gas), since fossil fuels produce a lot of carbon dioxide
Eat less livestock (farm animals, such as cows, produce a lot of methane and waste) and possibly become vegetarian/vegan
Decrease deforestation (trees absorb carbon dioxide and release oxygen)
Recycle/reuse more items to decrease the amount of trash in oceans, forests, and other ecosystems
