Earth Day Quiz - Answer Guide

Congratulations on completing the Earth Day quiz! For those curious to learn more, here is the complete set of answers and resources:

1. Which of the following is the biggest cause of global warming?

  • Pollution from wildfires
  • Burning oil, gas, and coal
  • Deforestation
  • Increasing livestock farming
  • Solar radiation

The answer is burning oil, gas, and coal. Deforestation and livestock farming are also contributing factors. However, it is considered extremely unlikely that solar radiation caused the observed global temperature warming trend over the past half-century. Find out more about causes of global warming here. 

2. Which of the following is not a greenhouse gas?

  • Carbon Dioxide
  • Methane
  • Oxygen
  • Nitrous Oxide
  • Water Vapor

The answer is oxygen. Read more about the greenhouse effect here. 

3. What is the earliest point in time scientists believe greenhouse gases began warming the world's oceans?

  • Mid 1800s
  • Late 1800s
  • Early 1900s
  • Mid 1900s
  • Late 1900s

The answer is Mid 1800s. While human records show that global average temperature started to increase in the late 1800s and accelerated during the 1900s, new studies have brought this date forward to as early as 1830s based on fossil records. Learn more about the latest research here or here.

4. Which type of food has the highest carbon footprint?

  • Beef
  • Fish
  • Chicken
  • Cheese
  • Olive Oil
The answer is beef, which has by far the highest carbon footprint due to methane emissions from cows. Read more about the greenhouse gas emission of different food products here.

5. Which of the extreme weather events below is not commonly linked to global warming?
  • Exacerbated droughts
  • More frequent heatwaves
  • Stronger hurricanes and storms
  • Frigid temperatures in lower latitudes
  • Great earthquakes

The answer is great earthquakes. The link between climate and earthquakes is inconclusive. Read more about the effects of global warming here.

6. Which of the following is causing coastal cities to "sink"?
  • Rise of sea level
  • Excessive extraction of groundwater
  • Weight of urban development
  • Intensifying storms and abnormal weather patterns
  • All of the above
The answer is all of the above. In addition to rise of sea level driven by climate change, low-lying coastal cities are at risk of "sinking" due to land subsidence and accelerated urbanisation. Read more about the crises facing coastal communities here.

7. Which of the following has the biggest effect on curbing climate change?
  • Adopting a plant heavy diet
  • Cutting down on food packaging
  • Cooking over clean stoves
  • Throwing away less food
  • Composting your waste
The answer is throwing away less food, with adopting a plant heavy diet at a close second. While eating less meat is probably the most effective measure for individuals, food waste reduction is an even more impactful way to reduce carbon emissions. A third of all food production is wasted along the supply chain, accounting for 8% of global emissions. Read more about climate solutions here.

8. Which of the below household tasks uses the most electricity?
  • Turning on the portable air-conditioner in your bedroom for an hour
  • Washing and drying a single load of clothes
  • Keeping the LED light on for 3 days
  • Working on your laptop for a full working day

The answer is washing and drying a single load of clothes, with air-conditioning at a close second, though exact calculations may depend on specific appliances and settings. Washers and dryers are the third biggest energy consumers despite shorter period of use. Read more about what uses the most energy in your home here.