New data shows that CO2 levels have broken through 430 parts per million, an indication that human-caused global warming will continue to warp the environment.Earth’s atmosphere now has more carbon dioxide in it than it has in millions — and possibly tens of millions — of years, according to data released Thursday by the National Oceanic and Atmospheric Administration and scientists at the University of California San Diego.For the first time, global average concentrations of carbon dioxide, a greenhouse gas emitted as a byproduct of burning fossil fuels, exceeded 430 parts per million (ppm) in May. The new readings were...