Cities and Energy Quiz (National Geographic)

The world's cities occupy about 2 percent of the land on Earth. About what percentage of the world's greenhouse gas emissions can be attributed to cities?

• 70%

• 50%

• 20%

• 10%

On a per-person basis, greenhouse gas emissions in cities are often far below the national average, thanks to public transit, density and smaller living spaces. But which of the following cities has higher per-capita emissions than its nation's average?

• Brussels

• New York

• Beijing

• Seoul

Answer explanation

Beijing's per capita carbon emissions exceeded those of China as a whole because so much of the rest of the country is less developed than the capital.

Automobile traffic declined 20 percent in London in the first few months after it implemented a congestion charge program—tolls for vehicles entering the city's center—in 2003. What has happened to traffic since?

• It has remained stable

• It has risen to the level before the congestion charge

• It has decreased

• It has increased

A 2011 Stanford University study considered the urban heat island effect and its impact on global warming. What did the researchers conclude?

• It plays no role

• It is far less a contributor than fossil fuel emissions

• It is as significant as fossil fuel emissions

• It is more significant than fossil fuel emissions

Answer explanation

Researchers concluded that the excess heat released by cıtıes (compared to vegetated areas) is responsible for between 2 and 4 percent of the gross global warming since the Industrial Revolution. In contrast, greenhouse gases contributed 79 percent; black carbon, about 18 percent.

A survey of more than 430 U.S. cities showed that the average automobile commuter spent 34 hours stuck in traffic congestion in 2010. How much gasoline was wasted, or burned while idling, as a result for each driver?

• 151 litres

• 53 litres

• 15 litres

• 3.8 litres

Rotterdam, in The Netherlands, ranked as highest among 100 global cities in terms of greenhouse gas emissions per person, according to a 2011 study. What is the most likely factor accounting for the city's high fossil fuel emissions?

• It has cold temperatures

• It has a young population

• It has a large population

• It is a port city

Answer explanation

As Europe's largest port, and a trading hub for petroleum products and major ship refueling center, Rotterdam has higher per-capita emissions than other cities of size or climate.

In 2022, Beijing faced pressure from critics because of a practice they said underestimated air pollution due to fossil fuel emissions. What was the practice?

• Not tracking automobile pollution

• Not tracking smokestack pollution

• Only tracking small particle pollution

• Only tracking large particle pollution

Answer explanation

Beijing meteorological authorities were delivering "good" air quality readings at the same time the US embassy in Beijing gauged pollution to be at "hazardous" levels, because the city was tracking only coarse particle pollution, and missing fine particles released by petrochemical industries and vehicles.