- World’s cities may be as much as eight degrees Celsius warmer by 2100 due to a dual onslaught of global warming and localised urban heating.
- 5 degrees Celsius of the total would be attributed to average global warming.
- The rest would be due to the so-called urban heat island (UHI) effect, which occurs when cooling parks, dams and lakes are replaced by heat-conducting concrete and asphalt — making cities warmer than their surrounds.
Effect of this temperature rise:
- Such a temperature spike can have dire consequences for the health of city-dwellers, robbing companies and industries of able workers, and .
- With the warming of cities, the median city, right in the middle of the range, stands to lose between 1.4% and 1.7% of GDP per year by 2050 and between 2.3% and 5.6% by 2100.
- Cities cover only about 1% of the earth’s surface but produce about 80% of gross world product and account for around 78% of energy consumed worldwide.
- They produce more than 60% of global carbon dioxide emissions from burning coal, oil and gas for fuel
What can be done:
Local actions to reduce UHI — such as planting more trees or cooling roofs and pavements, can make a big difference in limiting warming and minimising costs.