Challenges of the Future

5-Global warming:\ Definition: the phenomenon of increasing average [air](https://www.britannica.com/science/air) [temperatures](https://www.britannica.com/science/temperature) near the surface of [Earth](https://www.britannica.com/place/Earth) over the past one to two centuries. Climate scientists have since the mid-20th century gathered detailed observations of various [weather](https://www.britannica.com/science/weather) phenomena (such as temperatures, [precipitation](https://www.britannica.com/science/precipitation), and storms) and of related influences on [climate](https://www.britannica.com/science/climate-meteorology). \Causes: Global warming is primarily a problem of too much carbon dioxide (CO2) in the atmosphere—which acts as a blanket, trapping heat and warming the planet. As we burn fossil fuels like coal, oil and natural gas for energy or cut down and burn forests to create pastures and plantations, carbon accumulates and overloads our atmosphere. Certain waste management and agricultural practices aggravate the problem by releasing other potent global warming gases, such as methane and nitrous oxide.

Which energy will best replace fossil fuels

Excessive use of fossil fuels has recently (over the last 30 years) revealed itself as a major problem that could have catastrophic consequences, There are many paths to address this problem. The path most travelled recently is to replace fossil fuels with "renewable" fuels like wind, solar or even nuclear. There has also been a large push towards "biofuels" which to many means turning plants that could be food into fuel instead. There are obvious pros and cons with that approach.

Immigration

1-Migration vs immigration

Whether it’s in the news or an overheard conversation, it’s not uncommon to hear the words migrant and immigrant used interchangeably.But they don’t mean the same thing. Migrant is a broad term that applies to an individual who willingly leaves home and moves from one place to another, most often in search of employment. This includes people who:

• Move from one region to another within the borders of their own country (internal migration); or
• Move from their country of birth to another country or countries.

A migrant is an individual who is purposefully on the move in search of a better life, but can return home at any time if they so choose. An immigrant is an individual who willingly leaves their country of origin and legally enters another country where they are granted permission to permanently resettle, thus qualifying them to work without restriction.

2-Problems and difficulties that people coming from the countryside can face

\*crowding. Cities are crowded in at least two ways. The first involves residential crowding: large numbers of people living in a small amount of space. City streets are filled with apartment buildings, condominiums, row houses, and other types of housing, and many people live on any one city block.

\*household crowding: Dwelling units in cities (apartments and houses) are typically small because of lack of space, and much smaller overall than houses in suburbs or rural areas. This forces many people to live in close quarters within a particular dwelling unit, especially if they are low-income individuals or families.

\Traffic congestion and the sheer amount of traffic in cities also contribute mightily to air pollution, which we consider here as a separate urban problem. Traffic creates pollution from motor vehicles’ exhaust systems, and some cities have factories and other enterprises that also pollute. \Crimes, violence, discrimination, pollution...

3-Illegal immigration, why do Tunisians risk their lives to reach Europe : The vast majority of people setting off into the Mediterranean are not asylum seekers, but seeking a better life. There is no doubt that the reasons these people leave their country and come to the EU are mixed, but there is also no doubt that their countries are embroiled in conflicts and widespread human rights abuses. These people are often poor, desperate, and hopeless, they are looking for a new life which is better that the one they have back home.

4-Brain drain: Brain drain is the migration of skilled human resources for trade, education, etc.[1](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1275994/#ref1) Trained health professionals are needed in every part of the world. However, better standards of living and quality of life, higher salaries, access to advanced technology and more stable political conditions in the developed countries attract talent from less developed areas. The majority of migration is from developing to developed countries.

When brain drain is prevalent in a developing country, there may be some negative repercussions that can affect the economy. These effects include:

• Loss of tax revenue
• Loss of potential future entrepreneurs
• A shortage of important, skilled workers
• The exodus may lead to loss of confidence in the economy, which will cause persons to desire to leave rather than stay
• Loss of innovative ideas
• Loss of the country's investment in education
• The loss of critical health and education services

Brain drain is usually described as a problem that needs to be solved. However, there are benefits that can be derived from the phenomena. When people move from LDC countries to developed countries, they learn new skills and expertise, which they can utilize to the advantage of the home economy once they return. Another benefit is remittances; the migrants send the money they earn back to the home country, which can help to stimulate the home country's economy.