I'm sure the warming doesn't help, but as has been mentioned, the main reason why the world's lakes are draining - we're using most of the water that goes into them. Most of the water that would be filling Lake Chad is taken out of the rivers to use in agriculture. Soil damage from poor crop management and overgrazing spreads deserts more than lack of rainfall.
Believe it or not, most of the world's ecological problems stem from farming. Deforestation, desertification, eutrophication, soil salination, overpopulation, extinction...
Farmers: Destroying the world since 5000BC.
Whether it's man or nature warming the planet up it is clear we won't have much water left.
Stock up on ammo and leave one for yourself, this is going to get ugly sooner rather than later. And here I was looking forward to a good life like my parents and maybe their parents before them.
Oh, be quiet. Doomsayers here expecting to run out of water probably live either in the US or Western/Northern Europe. You're fine. You'll need some water recycling infrastructure eventually, but that's the fault of population levels and it isn't beyond your means to build. It's not going to stop raining. Actually, total world rainfall should increase as the world warms. It's just that it won't all fall on the places it falls now - some places will be wetter even as others dry up.
Isn't there a lake in Chili that comes and goes every so often? Have any new lakes popped up any where?
Plenty, actually. Reservoirs!
..just modifying the habits and lifestyle of the top 10% of us would likely be enough.
This isn't really true. Partly because China's coal-fueled factories and power stations will counter any savings we make, but mostly because the changes required to negate emissions entirely with current technology are staggering.
We'd have to give up fossil fuels completely, which at the moment means no transport and barely any electricity. That's not a change of habit - that's social collapse. Not to mention the fact that actually stopping people from doing these things would require serious military intervention and general domestic oppression. No, we're stuck until we find another source of power. Solar, nuclear, water, wind, fusion, magic, whatever. Something. We could sequester the carbon, but that requires too much energy - it's a waste of time at the moment.
Sure, we can reduce the problem with good habits, efficient infrastructure and investment in technology, but there isn't much we can actually do to stop it. We're not all going to die, though. It'll be an environmental disaster, sure, but so are hurricanes and tsunamis and volcanoes and...