ClimateWire: The upper ocean warmed considerably over the past decade and a half, according to a new study that attempts to make sense of conflicting analyses of the amount of heat stored in the world’s seas. Between 1993 and 2008, the study finds, the upper 700 meters of the oceans absorbed about 0.6 watts per square meter of energy. That is roughly equivalent to the power of 2 billion copies of the atomic bomb the United States dropped on Hiroshima, Japan, during World War II, said lead author …