World Environment Day Quiz

What is the leading cause of land degradation? 

• Overgrazing from livestock

• Unsustainable resource extraction

• Rapid urbanization

• All of them

Answer explanation

Land degradation is among the world’s most pressing environmental crises. It refers to the reduction or loss of ecosystem productivity and has several interrelated causes. For example, unsustainable agriculture and urbanization reduce productive land area, leading to overgrazing from livestock and impeding productive ecosystems. Reforming agricultural subsidies to work with nature and not against, and ensuring more equitable access to land are examples of effective policymaking. Indigenous and traditional knowledge can also inform sustainable land management.

What percentage of the Earth’s population suffers from the impacts of land degradation? 

• 20 %

• 40 %

• 60 %

• 80 %

Answer explanation

Land degradation affects approximately 3.2 billion people, or 40 per cent of the world’s population. It threatens well-being and disproportionately harms those who are least equipped to cope such as rural communities, farmers and the poor. They suffer from food shortages, failing harvests, volatile food prices, and climate impacts caused by the release of carbon from degrading land. By 2030, land degradation and desertification could force 135 million people to migrate, creating social and economic inequalities. 

What is Earth’s most biodiverse habitat? 

• Coral reefs

• Deserts

• Forests

• Soil

Answer explanation

Almost 60 per cent of all species live in soil. These species include microbial organisms, medicinal fungi and mammals. Soil also stores significant carbon emissions and produces 95 per cent of our food. One spoonful of healthy soil includes more living organisms than there are people on the planet. Yet soil erosion affects some 20 per cent of all farmlands and is rising due to deforestation and cropland expansion. 

What can you do to tackle land degradation?  

  

• Plant trees everywhere

• Change food choices and waste collecting habits

• Recycle plastics

• All of the above

Answer explanation

The global food system is the biggest driver of biodiversity loss and significantly affects land degradation. Including more pulses in your diet and making other sustainable food choices can actually help repair soil. You can also prevent land degradation by collecting kitchen waste to compost. Remember, tree-planting doesn’t work everywhere and can harm areas like grasslands. Plastic pollution is a threat to soil and must be addressed, but it is not the biggest driver of land loss. 

The Sahara and other hot deserts are dead and have no biodiversity value. 

• True

• False

Answer explanation

As carbon sinks, deserts play a vital role in climate regulation and are home to billions of people. The Sahara hosts hundreds of plant, mammalian, reptile and avian species, as well as arthropods like spiders and scorpions. Desertification primarily refers to land degradation caused by human activities. This threatens essential functions and biodiversity in other ecosystems. While humanity must prevent desertification, it must also protect and rewild existing natural deserts. 

Drought affects 55 million people a year, and is not as big of a deal as land degradation and desertification, which affect billions of people. 

• True

• False

Answer explanation

Drought, land degradation and desertification are interrelated crises that require unified action from all stakeholders. Drought, which is primarily caused by the climate crisis, is the most serious hazard to livestock and crops globally. Some 700 million people are at risk of being displaced due to drought by 2030. It has widespread implications on human well-being, ecosystem health and economic prosperity – even for those who don’t live in drought-prone areas.  

In the context of the UN Decade on Ecosystem Restoration, a global push to protect and revive ecosystems, countries have vowed to restore around how many hectares of degraded land?  

• 250 million

• 500 million

• 1 billion

Answer explanation

Currently, 115 countries have committed to restore between 765 million and 1 billion hectares of land – an area larger than China. Some 12 million hectares of productive land degrades yearly. The UN Decade on Ecosystem Restoration encourages governments, businesses and more to ramp up restoration and put the world on track for a sustainable future. 

 

The equivalent of one football pitch of soil is eroded in how many seconds?

• 5 s

• 120 s

• 60 s

Answer explanation

• Every year more than 24 billion tonnes of priceless topsoil are washed or blown away worldwide, as the land is overcultivated and overgrazed and trees and forests are cut down. 

Trees in urban areas can cool the air by up to (temperature)

• 15°C

• 5°C

• 1°C

• no change

Answer explanation

Urban tree plantation reduces air conditioning needs by 25 per cent. Urban trees provide multiple health benefits such as cleaner water. They also clean the air and reduce flooding among many other benefits.

More than half of the world’s forests are found in only five countries

• Canada, China, Indonesia, Australia and Democratic Republic of the Congo

• Brazil, India, China, Russian Federation and USA

• Canada, India, China, Russian Federation and USA

• Brazil, Canada, China, Russian Federation and USA

Answer explanation

Forests cover 31 per cent of the Earth but they are not equally distributed! more than half of the world’s forests are found in only five countries: Brazil, Canada, China, the Russian Federation and the USA.

FUN FACT: The largest organism on Earth is a fungus in the Blue Mountains of the United States. Covering about 965 hectares of land, the fungus could be as ancient as 8,650 years, which would earn it a place among the oldest living organisms in the world.