how might the polar bears population suddenly increase? how might this affect the ecosystem?

There's been a lot of bad news for polar bears recently. In 2007, for example, scientists reported that if global warming continues unabated, the population could drop two-thirds by 2050.

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

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.