Trees act as organic air conditioners, especially in cities. However, a warming climate threatens their cooling capabilities as deadly pests, like scale insects, spread. This warming also alters growth patterns in wasps, which lay eggs inside scale insects, acting as a natural pesticide. The mismatch between host and parasite means more trees will suffer.
Germany's Sunniest
Nestled in the Black Forest, Freiburg, Germany prides itself on its green credentials. But some activists are concerned that this city is not doing enough, with new development plans that may undermine some of its gains.
The old city
How to Cool a City
A few years ago, Louisville, Kentucky found out it's the fastest warming city in the United States. This will have devastating health consequences for the city's 250,000 denizens. Now city officials are fighting back in what may the largest urban climate change mitigation effort in the country.