Data from sea sponges suggest the world has overshot a climate limit, new study says
CNNCNN — Using sponges collected off the coast of Puerto Rico in the eastern Caribbean, scientists have calculated 300 years of ocean temperatures and concluded the world has already overshot one crucial global warming limit and is speeding toward another. “The big picture is that global warming, and the urgent need for emission reductions to minimize the risk of dangerous climate change, has been brought forward by at least a decade,” Malcolm McCulloch, lead author of the study and marine geochemist at the University of Western Australia, said at a news briefing. “So, this is a major change to thinking about global warming.” However, several climate scientists have questioned the study’s findings, especially using one type of sponge from one location in the Caribbean to represent global temperatures. Gabi Hegerl, a professor of climate system science at the University of Edinburgh, said the study was “a nice new record that illustrates how temperatures in the Caribbean started to rise over the industrial period.” But, she added in a statement, “the interpretation in terms of global warming goals overstretches it.” Some went further. Yadvinder Malhi, professor of ecosystem science at the Environmental Change Institute, University of Oxford, said the way the findings have been communicated were “flawed” and have “the potential to add unnecessary confusion to public debate on climate change.” A co-author of the study defended its robustness and argued that temperature changes in the part of the Caribbean the sponges came from have always mimicked changes around the globe.