Greenhouse gas levels currently expected by mid-century will produce devastating long-term droughts and a sea-level rise that will persist for 1,000 years regardless of how well the world curbs future emissions of carbon dioxide, an international team of scientists reported yesterday.

“I think you have to think about this stuff as more like nuclear waste than acid rain: The more we add, the worse off we’ll be,” NOAA senior scientist Susan Solomon told reporters in a conference call. “The more time that we take to make decisions about carbon dioxide, the more irreversible climate change we’ll be locked into.”