New Scientist: After the cold, the heat. High pressure spreading across the UK from Siberia last spring brought record cold temperatures. Now more high pressure, this time from the tropical Atlantic, is bringing a sweltering heatwave. These high-pressure zones are blocking the jet stream which usually brings the country's normal changeable weather. "Blocking highs" are an increasing theme of North American weather reports too, bringing concern of a long-term shift. New Scientist looks at the issues.
What's going...