It seems to me that many of the problems facing the world today are very technically easy to solve but very socially difficult to solve. I believe that humanity can solve these kinds of problems, if only enough people mobilize themselves. For example:
- Ethnic, gender, religious, national, wealth, etc. equality. Treat everyone with fairness and respect (in every way), heavily tax or outlaw wealth greater than a certain amount (I suggest $1 million for individuals and $100 million for companies), collaboratively create a global government (i.e., the UN with more power), use the Internet to let everyone collaboratively construct a common human language (which everyone must learn in school, but which is optional to use in daily life), and so on.
- Global warming. We have many ways of generating clean energy: solar, wind, hydroelectric, hydrogen, nuclear fusion (coming soon), etc. — we just need to use them on a larger scale.
- Over-population. People around the world need to either control themselves or use modern birth control or sterilization methods.
- War. “Nothing will end war unless the people themselves refuse to go to war” (Albert Einstein).
- Direct democracy. Many critical government and corporate services are already available on the Internet: healthcare, banking, etc. Why not voting? Using the Internet, every citizen who wants to could easily vote on the issues of the day and votes could be counted instantly, replacing most politicians and letting the people represent themselves.
- Pollution and destruction of nature. Stop using plastic or require everyone to recycle it, stop using synthetic chemicals as much as possible, use electric or other clean-energy vehicles (hydrogen, bicycles, etc), and so on. Stop large companies from using so many pesticides and large harvesting machines, fracking, oil drilling, replacing humans with machines, emitting toxic chemicals from factories, etc.