Mexico City is the biggest city in North America, and like most big cities, it has a lot of cars and traffic. Yet, over the past 30 years, it’s gone from being considered the most polluted city in the world to ranking 999th among global cities for air pollution. A small part of that has been taming traffic and the development of a robust bicycling culture. John Burnett reports from Mexico City.
Porto Alegre, the capital of Brazil’s southernmost state, has had to adapt after the metropolitan area of roughly 4.5 million people lost its only international airport. A month ago, unprecedented flooding sank major parts of the city. The rains have continued and the city’s airport is still underwater. So, officials have gotten creative.
Lakes all over the world — like the Aral Sea in Central Asia — are receding because of climate change and dwindling water resources. But Kazakhstan managed to save part of the Aral Sea. The successes and shortcomings of the achievement can provide lessons for other lakeside communities.