World's Biggest Problems

1. There are millions of refugees fleeing recent conflict. The U.S. does not see the bulk of this, because we are separated by sea. These people are trying to survive, and go to a safer, more stable environment. However, many countries, especially in Europe are worried that they would be overburdened helping these people.
As of right now many refugees aren't able to work in the countries they are seeking refuge in. If the EU created an international work program, that enabled these people to become more productive members of society, many of the overburdening issues, could be minimized.  The program could provide not only paying jobs, but classes on learning languages, becoming citizens, and adjusting to the new country.

2. Many countries are implementing some sort of complex spying and data collection program on it's own citizens (and sometimes other countries). The extent the NSA does this means that more or less anything ones does that touches the internet is traced, profiled, and saved. This can include things ranging from private emails, to health records. I believe this to be a violation of basic human rights. In addition to the ethical issue this brings up, there is now way to know that the information they collect is secure. This means that a hacker could potential take any of this information, and considering this has happened several times recently, is a very real danger.
The reason many of these programs are put in place is to combat terrorism or some other indisputable wrong doing. However, officials have stated that so far the data collection has only assisted in learning about the individuals after the fact. Information that could, and often is discovered using regular police work. Since it seems these costly systems are not doing what they set out to do, they should be closed, and all data collected permanently deleted.

3. Unfortunately the world environment is at threat. Pollution is is damaging the climate of many areas, causing change that is killing off many species as well as resources that are needed with the growing population. It's causing weather systems to behave more erratically than normal, which is putting millions of people at risk.
The world environment is very complex, which means solutions are hard to come to. However, the first big steps to take would setting stringent world wide environmental quotas on international trade. This would need rules that affect not only the worst offenders of pollution and destroying habitats, but also those who continue to trade with them.

4. In many third world countries, and even some more developed ones, energy can be inconsistent. To the point that having lights at night can be difficult and other valuable electronics, like a refrigerator to store food, impossible. This presents a very wide gap that is difficult to cross and overcome in the modern world. To top it off, often the only source of power is fossil fuels, leading to more pollution.
It would be beneficial to establish renewable energy sources, like solar panels and wind turbines, in these areas. They could be independent of an existing, unreliable infrastructure and provide clean power more regularly to the inhabitants.

5. There are many people in severe poverty aground the world, and even in the US. Even clean water and food can be hard to come by. This leads to malnutrition and death in many cases. Often these people are vulnerable to things like drought that destroy there crops and primary source of food or income.
There are several ways to help solve these issues. Dealing directly with crops, helping the farmers to diversify in both type of food and specific type of crop (for genetic diversity). This would reduce the damage that a disease or environmental damage. Increased education of the people would also assist in opening up employment possibilities, bringing new industries and creating a varied economy.

6. Terrorist attacks are another unfortunate issue on the world stage. They are often motivated by extremest mentalities against outside influence and internal cultural disagreements. Many people are killed, loose loved ones, and become more upset at the opposing group.
This a very tricky situation, because often outside influence is seen as a problem. One point of view would be to just leave these groups alone and let them sort out the issues themselves. However, this means leaving many innocent people at the mercy of extremist who will do harm. A more interconnected world, using things like the internet and social media could help bring more people closer together and present new ideas and opinions, but it would also requires people to have access to infrastructure to work.

7. Many people maintain a fear or hatred of others based of their race, religion, gender, sexual orientation, etc. This causes different groups a struggle to find work, feel ok with themselves, and be accepted in modern society. People being treated poorly due to factors they can't control should not be a problem in the twenty-first century.
Unfortunately changing social stigmas is no easy feat. These things are baked into cultures, and can only change over long periods of time. The best people can do to quicken these transitions are to learn more about the different groups and having personal interactions with them. It's easy to make something a faceless entity, but actually knowing people, and knowing what they have to go through, certainly can change individual beliefs.

8. Lack of economic mobility is a problem many individuals face for a variety of reasons. Many people may not have the agency over their own lives to do better, while others must fight social injustices to earn a spot where others start. This prevents many from being able to rise above the economic condition they were born into.
Providing better education, that helps give students the knowledge and understanding that they can control their destiny would help. Also making it easier and cheaper to access resources such as higher education would mean more people born into poverty have the option to be in higher paying positions.

9. History repeats itself, and often times people ignore the lessons from the past. The United States having a war in a region and leaving it destabilized, leading to a extremist leaders taking charge, is not new. It happened in World War I, where the Nazi party took charge and plunged the world into another bloody conflict. And it happened more recently with the Gulf Wars.
If we continue to let emotions dictate both the charge into battle, and how we treat the people afterwords, we will continue to have escalating conflict.As a society and government we need to treat others, even old enemies, with respect and human decency.

10. Many conflicts arise because people aren't willing to compromise. For instance, Israel and Palestine both want to live where they consider to be their home. However, there continued conflicts means many people are hurt and sacred sites damaged. Neither side is wining in this drawn out battle.
If each party looked that the core of the conflict and considered what they are trying to achieve, without pride or emotion clouding their thoughts, finding a solution for everyone would be much easier.

I want to point out that a paragraph devoted to each issue is not nearly enough to really explain it. So there is a whole lot of generalization going on.