The evidence that humans are causing climate change, with drastic consequences for life on the planet, is overwhelming. Experts began raising the alarm about global warming in 1979, a change now ...

Since Philadelphia is arranged on a grid system, the mostly one-way roads are easy to navigate. Helpful maps are posted along street corners across the city – watch for the "Walk! Philadelphia" signs ...

Chicago's eastern boundary is formed by Lake Michigan, and the city is divided by the Chicago River into three geographic sections: the North Side, the South Side and the West Side. These sections ...