An international team of researchers led by engineers from the University of Toronto analyzed resource consumption data from the world’s twenty-seven largest cities. The survey, published this week, analyzed cities’ natural gas and electricity use, and waste disposal. Findings could be used to create strategies for making the worst offenders more sustainable.
Since 1970, the number of megacities (population of 10 million) has grown from eight to twenty-seven in 2010 - that number is expected to jump to thirty-seven by 2020. These cities produce 12.6% of the world’s waste and consume 9.7% of its electricity despite housing only 6.7% of the world’s population. But not all megacities are created equal.
Wealth and geography are major indicators of a megacity’s greenness. Cities in colder climates tend to consume more fuel for heating and wealthier cities tend to consume and waste a disproportionate amount of just about everything. Some cities, though, have implemented policies to use fewer resources that have overcome cold climates or great wealth. Both New York and Tokyo have similar climates and wealth but not consumption. According to Chris Kennedy of the University of Toronto, “the New York metropolis has 12 million fewer people than Tokyo, yet it uses more energy in total: the equivalent of one oil supertanker every 1.5 days.” Tokyo’s policies for water conservation and efficient transportation give it an edge over cities like New York.
Other successful policies can be seen across the globe. London has increased taxes for waste disposal and prices for electricity. Seoul has implemented a water reuse system, and Moscow has built the largest shared heating system in the world.
The populations of megacities are rapidly growing; the growth in energy demand and GDP is growing even faster. For the developing world the combination of more people and more consumption per capita is putting an enormous strain on the planet’s resources. However, the study indicates that key policy decisions can make an incredible difference in the world’s resource usage.
Source: University of Toronto