Quiz of the Day
Earth Day
Wednesday, 22 April 2026
56th Earth Day — climate facts, endangered species, environmental milestones
1. In what year was the first Earth Day celebrated?
- 1960
- 1970
- 1980
- 1990
The first Earth Day on April 22, 1970 saw 20 million Americans take to the streets in protest. It led directly to the creation of the US Environmental Protection Agency and the Clean Air Act.
2. What is the most abundant greenhouse gas in Earth's atmosphere?
- Methane
- Carbon dioxide
- Nitrous oxide
- Water vapour
Water vapour accounts for about 60% of the greenhouse effect. However, CO₂ is the primary driver of climate change because human activities are directly increasing its concentration.
3. How much of Earth's water is freshwater available for human use?
- About 10%
- Less than 1%
- About 3%
- About 25%
While about 2.5% of Earth's water is freshwater, most is locked in ice caps and glaciers. Only about 0.5% is accessible surface freshwater in lakes, rivers, and shallow groundwater.
4. Which layer of the atmosphere protects us from harmful ultraviolet radiation?
- Stratosphere (ozone layer)
- Troposphere
- Thermosphere
- Mesosphere
The 1987 Montreal Protocol banned ozone-depleting chemicals and is considered the most successful environmental treaty ever. The ozone hole is expected to fully recover by around 2066.
5. What is the Great Pacific Garbage Patch?
- A landfill in California
- A floating mass of ocean plastic debris
- A polluted river delta
- A recycling centre
The Great Pacific Garbage Patch covers an area roughly twice the size of Texas. Most of it is microplastics too small to see — it looks more like a cloudy soup than a solid island of rubbish.
6. Which country produces the most renewable energy in total?
- United States
- Brazil
- Germany
- China
China leads the world in total renewable energy capacity, particularly in solar and wind. In 2023, China installed more solar panels than the entire rest of the world combined.
7. What percentage of the Amazon rainforest has been lost to deforestation?
- About 17%
- About 50%
- About 5%
- About 30%
The Amazon produces about 6% of the world's oxygen and holds 10% of all species on Earth. At current rates, scientists warn it could reach a 'tipping point' where it converts to savanna.
8. What is 'biodiversity'?
- The study of biology
- The number of trees in a forest
- The amount of rainfall in a region
- The variety of life in a particular habitat
Earth is estimated to have 8.7 million species, but only about 1.2 million have been identified. Scientists believe species are going extinct 1,000 times faster than the natural background rate.
9. Which animal is the symbol of the World Wildlife Fund (WWF)?
- Giant panda
- Tiger
- Elephant
- Polar bear
The WWF chose the panda in 1961 partly because it was endangered and partly to save on printing costs — the black-and-white logo was cheaper to reproduce. Conservation efforts have moved pandas from 'endangered' to 'vulnerable'.
10. What is the largest source of human-caused greenhouse gas emissions?
- Transport
- Energy production
- Agriculture
- Industry
Burning fossil fuels for electricity and heat accounts for about 25% of global greenhouse gas emissions. Transitioning to renewable energy is considered the single most impactful climate action.
11. How long does a plastic bottle take to decompose in the ocean?
- About 450 years
- About 50 years
- About 1,000 years
- About 150 years
Plastic never fully biodegrades — it just breaks into smaller and smaller pieces called microplastics. These have been found everywhere from the Mariana Trench to Mount Everest to human blood.
12. Which international agreement aims to limit global warming to 1.5°C above pre-industrial levels?
- Paris Agreement
- Kyoto Protocol
- Montreal Protocol
- Rio Declaration
The Paris Agreement was adopted by 196 countries in 2015. To meet its 1.5°C target, global CO₂ emissions would need to reach net zero by around 2050 — a goal many scientists consider increasingly difficult.
13. What is composting?
- Decomposing organic matter into nutrient-rich soil
- Burning organic waste
- Filtering water through soil
- Recycling plastic materials
About one-third of all food produced globally is wasted. Composting diverts food waste from landfills where it would produce methane — a greenhouse gas 80 times more potent than CO₂ over 20 years.
14. Which country was the first to ban single-use plastic bags nationwide?
- France
- Denmark
- Bangladesh
- Kenya
Bangladesh banned plastic bags in 2002 after they were found to be a major cause of devastating floods — blocking drainage systems across the country. Kenya followed with one of the strictest bans in 2017.
15. What natural process do trees use to absorb carbon dioxide from the atmosphere?
- Photosynthesis
- Osmosis
- Transpiration
- Respiration
A single mature tree can absorb about 22 kg of CO₂ per year and produce enough oxygen for two people. The world's forests absorb roughly 2.6 billion tonnes of CO₂ annually.