Brainwave!
I've solved all mankind's problems with one simple solution!
We need to find a way to make us smaller!
Not a little bit smaller but, much smaller.
We are getting bigger so we need more space, food etc.
If we were small we would not only need less, time would seem longer. Some insects live their whole lives in a day, so we wouldn't have to live as long, no need for medical treatment that makes us live longer.
Makes perfect sense!