During the fall, tree leaves drop and gather on train tracks throughout Europe and North America, which can lead to serious problems for railways. Gathered leaves get wet from rainfall and then are crushed by train wheels, which turns the leaves into a hard, Teflon-like substance that coats the rails. The residue makes it harder for train wheels to grip the rails, which means trains have to move more slowly to be safe and to make sure their wheels don't slide on the rails when the train is slowing down. The precautions can cause some pretty lengthy delays for passengers.
Dozens of the world's top climate scientists have gathered in Japan this week with representatives from around 100 countries to work on the latest United Nations report about climate change. According to leaked drafts, the report is all but calling the climate situation an emergency: Far from causing future problems for a few species bearing white fur or feathers, hotter temperatures are already changing local conditions for humans, and a lot faster than most climate researchers once believed possible.
