2. Why is irrigation not necessarily an answer to potential drought from
global warming? ​

because to irrigate you need purified or rain water to not kill your plants/animals and once you've used your fresh water how would you get more purified water?

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.