London - In Britain summer 2000 could go down as one of the worst in the last half century, with July already contradicting the trend towards global warming. Forecasters have revealed that the first two weeks of July were the coldest summer period for nearly 50 years. The temperature at Stansted Airport at midday yesterday was 13, 10 lower than average for this time of year. The Meteorological Office predicts that the first two weeks of August will be bright and sunny.