Global environmental problems and climate change
A global issue is a problem that crosses borders and needs many countries to solve it.
- Climate change: burning coal, oil and gas adds carbon dioxide to the air. This gas holds heat, so the Earth warms, ice melts, sea level rises and weather becomes more extreme.
- Air and water pollution: smoke, chemicals and plastic travel by wind and rivers.
- Loss of forests and species: cutting forests removes homes of animals and ends a store of carbon.
- Ozone layer: some gases once used in fridges thinned the ozone layer. Nations signed the Montreal Protocol (1987) and the layer is recovering. This is a success story of cooperation.
Resources and energy
Resources are things we take from nature. Non-renewable resources (coal, oil, natural gas, many metals) form over millions of years, so they run out. Renewable resources (sun, wind, water, biomass) are replaced or never run out.
- Demand for energy rises as populations and incomes grow.
- Fossil fuels are limited and cause climate change.
- Fix: save energy, make machines efficient, and shift to solar, wind and hydro power.
- Fresh water is also a resource: many places face water shortage.
Population, food, housing and poverty
World population is about 8 billion and still growing, mostly in lower-income regions. More people need more food, homes, schools and jobs.
- Food: the world makes enough to feed everyone, but about one-third of food is wasted and the rest is not shared equally, so hunger remains.
- Housing: fast growth of cities leads to crowded areas and slums.
- Poverty: hundreds of millions live on very little money. There is a development gap between wealthy and low-income regions in income, health and education.
Poverty and the environment are linked: poor families depend directly on land, water and forests, so damage hurts them first.
International cooperation and the SDGs
Since the problems cross borders, the solutions do too.
- Agreements: the Montreal Protocol (ozone) and the Paris Agreement (2015: keep warming well below 2 °C).
- Organisations: the United Nations and its agencies, the World Bank, the WHO and the FAO give money, advice and aid.
- Sharing technology and money: richer countries help poorer ones build clean energy and schools.
- The SDGs: in 2015 all UN members adopted 17 Sustainable Development Goals to reach by 2030, such as no poverty, zero hunger, clean water, affordable clean energy and climate action.
- You: save energy, waste less food, and choose fair and local products.
Key formulas and definitions
- Global issue = a problem that crosses borders and needs cooperation
- Years left = stock of a resource ÷ yearly use
- Per person share = total ÷ number of people
- Key term: renewable = replaced or never runs out; non-renewable = runs out
- Key term: SDGs = 17 UN goals for 2030
- Key term: Paris Agreement (2015) = deal to limit warming to well below 2 °C
Worked examples
1. A country has 120 units of oil and uses 10 units each year. For how many years will it last? If cooperation helps it cut use by 25%, how long then?
120 ÷ 10 = 12 years. A 25% cut makes the use 7.5 units a year. 120 ÷ 7.5 = 16 years.
2. Twenty pieces of food are shared equally among 10 people. How many does each get?
20 ÷ 10 = 2 pieces each. In the 3D, press Share to see the equal shares.
3. Give one example of a problem that was reduced by international cooperation.
The thinning ozone layer. After countries signed the Montreal Protocol in 1987 and stopped using the harmful gases, the layer began to recover.
Common mistakes
- Thinking global issues belong only to rich or only to poor countries. They affect everyone.
- Saying there is not enough food in the world. The main problem is waste and unequal sharing.
- Mixing weather and climate. Climate change is a long-term change, not one hot day.
- Thinking one person's action does not matter. Habits of many people add up.