By Anne T. Sulton, Ph.D., J.D.
JA Senior International Correspondent
According to the USA’s Environmental Protection Agency, greenhouse gases “trap heat in the atmosphere”.
Among these gases are carbon dioxide (produced in part by burning fossil fuels), methane (results in part from food production), nitrous oxide (emitted in part during wastewater treatment), and fluorinated gases (caused in part by industrial activities).
Because these gases “trap heat in the atmosphere,” they cause the entire planet to warm. The global warming contributes to worldwide climate change. Signs of climate change include some places being too warm too long (heat waves) and some places being too wet too often (flooding).
According to an article authored by Ting Wei, et al. and published July 12, 2021, by Frontiers in Sustainable Cities, with editorial offices based in Switzerland, scientific reports show that more than 70% of greenhouse gas emissions are attributable to cities. On-road transportation in cities accounts for about 30% of these planet-damaging emissions.
Essentially, cities worldwide must do more now to reduce greenhouse gas emissions because their populations are increasing at an astonishing pace.
Currently, there are at least 31 megacities, each with a population exceeding 10 million people. Among these are Tokyo with 38 million, Delhi with 26 million, Shanghai with 24 million, New York-Newark with 18 million, Sao Paulo with 21 million, Los Angeles with 12 million, and Paris with 10 million.
The United Nations reports that by the year 2030 “urban areas are projected to house 60 per cent of people globally.” It projects at least 43 megacities by the year 2030, with Delhi growing to 36 million, Shanghai growing to 30 million, Lagos growing to 24 million, Mexico City growing to 23 million, Manila growing to 16 million, Lima growing to 12 million, and London growing to 11 million.
Daniel Hoornweg and Kevin Pope, at the University of Toronto, report that by the year 2050 Mumbai will have 42 million residents, Lagos 32 million, Cairo 24 million, Khartoum 16 million, Istanbul 14 million, Chicago 12 million, and Moscow 10 million. Their data extrapolations show that by the year 2075 Kinshasa will be home to 58 million. By the year 2100, Lagos will grow to 88 million residents and be among 16 cities with populations exceeding 40 million.
When – by what date certain – will the world’s megacities set and meet now urgent greenhouse gas reduction goals?