Agence France-Presse: Big changes in the circulation of the Atlantic Ocean probably have an impact around the globe, according to a study published Wednesday that touches on a key aspect of climate change. Scientists delved into dramatic swings in climate that are believed to have occurred during the last Ice Age, about 110,000 to 10,000 years ago. Until now, the evidence for these swings has come only from the northern hemisphere, leaving a knowledge gap about what happened to the climate in the …