BBC: Global warming will significantly increase the frequency of lightning strikes, according to US research. The research, published in Science, was carried out with the help of data from a US network of lightning detectors. The teams says they have calculated how much each extra degree in temperature will raise the frequency of lightning. "For every two lightning strikes in 2000, there will be three lightning strikes in 2100," said David Romps, at the University of California, Berkeley. As well...