[HIGHLIGHTS] Climate change: Caribbean sponges indicate earlier onset of global warming

Study of sponges from the Caribbean suggests that global warming may have started earlier than thought. Global average surface temperatures could already be 1.7 degrees Celsius above the temperature level before the industrial revolution.

Australian and US scientists derived this from studying the skeletons ofSponges in the Caribbean Sea. But the study is controversial, with some researchers calling it "unconclusive" and "unquestionably flawed" and calling for major corrections to climate models.. The study was published in the journal Nature Climate Change.