Over use and abuse of our natural resources; the greenhouse affect and climate changes (for example, polar caps will be gone by 2040); loss of hundreds if not thousands of animal species; and starvation and pestilence. All of this may be cyclical or maybe not, but it is the most important problem we now should face at an accelerated rate.
As far as our human frailities, that has been so since the beginning of time.
Probably nuclear weapons. Eventually every 3rd world despot will have his own nuclear arsenal. One of them gets an itchy trigger finger, and everyone else uses that as an excuse to blow up their neighbor.
Environmental issues, no doubt about it ! Lack of water supply, global warming effect, all being the consequence of irrational economic development during last two centuries or so. If we don't figure out ( and very soon ) what is crucial to our survival ( and quality of life ) and which are the elements that keep on hindering us on the way to better world we will face ever more trouble !
Someone stated, when the sun starts to burn out, we'll be fried as it becomes a white dwarf. That's a long way off. NASA has stated that a very near Earth asteroid is due in 2029. I'm curious to see what kind of panic of panic that brings about. Since many panic about a stupid Mayan calender misunderstanding of 2012, who knows how people will react with a real threat?
When our sun's outer photosphere extends near the Earth's orbital path, humanity will have a huge, huge problems. Before that, the primary problems will revolve around various forms of imperialism, war, starvation, lack of access to essential resources - stuff like that, all of which are interconnected.
Look in the real world.
Decode this lyrics " You'll see "
"Seasons in the sun"
"River of no return"
"Money, money, money"
"All for the money"
Life cycles of water?
The gifts of life vital for the survival of Mankind in time?
For not harnessing the gifts of life?
Not harnessing the streams and rivers?
Lack of knowledge on what is rainfall, high and low tide is all about in time?
How mist being created into rainfall?
How salty sea water being filtered with storage as clean water?
Taking for granted drinking water come from the shelf of shopping mall?
How does it cost to desalinate one liter of sea water into one liter of drinking water?
Can desalination work without electricity?
Can it work without fuel?
Then what will the lost generation do in the near future?
Crawling down to the sea shore for water?
1 Timothy 6.7
What do you think?