average sea level has risen eight inches in the past century. and that doesn't only mean more flooding. those higher sea levels also increase coastal erosion. in california, houses have already gone tumbling into the sea as the coast is worn away. but today's report says florida faces the greatest threat as sea levels rise. beach erosion is already an ongoing battle in some communities. the study says one out of ten homes in miami could be lost by 2030. there is disagreement among scientists about just how fast sea levels are rising and what should be done about it. and, scott, those still skeptical of climate change say studies like the ones released today are estimates with no proven forecasting ability. >> pelley: john, thank you very much. so why is it so warm so early? well, it's the high altitude wind called the jet stream. because of low pressure in the north atlantic, the jet stream