Worldwide emissions of carbon from the burning of fossil fuels fell by 0.5 percent last year, the first drop since 1993, according to new estimates from the Worldwatch Institute. This decline took place even as the world economy expanded by 2.5 percent last year, undermining the argument that reducing greenhouse gas emissions to combat climate change will stifle economic growth. In other climate change news, large areas of the world’s oceans are dropping in salinity as global warming leads to more rain in sub-Antarctic waters, according to research published in today’s issue of the journal Nature.