I read that by the year 2070, three billion people will live in areas too hot for human habitation if global warming continues at its present rate. What do you think?
You are correct in your assessment. Researchers believe mankind does best in areas that experience annual temperatures between about 50 and 60 degrees. If global temperatures continue increasing at the rate they have in the past 30 years, large swaths of territory would experience extreme heat. Places such as northern Africa, portions of India, the Middle East, southeast Asia, South America and Australia would experience annual temperatures in excess of 84 degrees, the cutoff point for “extreme heat.” Many of those areas are presently experiencing rapid population growth.