Bjorn Lomberg makes some interesting arguments on how cities around the world are experiencing high temparature rises, are coping with and what possible low-cost solutions would be.
Most of the world’s urban areas have already experienced far more dramatic temperature hikes over the past few decades than the 2.6°C increase expected from global warming over the next hundred years.
Today, the fastest-growing cities are in Asia. Beijing is roughly 10°C hotter than the nearby countryside in the daytime and 5.5°C warmer at night. There are even more dramatic increases in Tokyo. In August, temperatures there climbed 12.5oC above the surrounding countryside, reaching 40oC – a scorching heat that affected not only the downtown area, but also covered some 8,000 square kilometers.
Looking at a fast-growing city like Houston, Texas, we can see the real effect of the urban heat island. Over the last 12 years, Houston grew by 20%, or 300,000 inhabitants. During that time, the night time temperature increased about 0.8°C. Over a hundred-year period, that would translate to a whopping 7°C increase.
Even as temperatures have risen, heat-related deaths have decreased, owing to improved health care, access to medical facilities, and air-conditioning. We have far more money and much greater technological ability to adapt than our forebears ever did.
These options are simple, obvious, and cost-effective. Consider Los Angeles. Re-roofing most of the city’s five million homes in lighter colors, painting a quarter of the roads and planting 11 million trees would have a one-time cost of about $1 billion. Each year after that, this would lower air conditioning costs by about $170 million and provide $360 million in smog-reduction benefits. And it would lower LA temperatures by about 3°C – or about the temperature increase envisioned for the rest of this century.