An Hawaii monitoring station tracks the amount of atmospheric carbon dioxide and on Thursday that amount hit a record. The publication Atlantic reports in 1988, NASA scientist James Hansen predicted carbon dioxide would reach 350 parts per million by 2013 and last week’s 400 ppm posted the highest daily mean concentration in human history. The environmental activist group called the recent reading a “grim but predictable milestone.” Scientists first registered the carbon scale briefly moving past 400 ppm last summer. Thursday’s record was the first time a daily average passed that point with predictions that 400 ppm readings could become commonplace. Energy efficiency, renewable power and emission reductions led to a 13 percent decrease in carbon emissions in the past seven years. Fastcast: A repeat.