Bleached and dying coral reefs are often held up as proof that global warming is laying waste to Earth's ecosystems. Now come reports that a number of reefs around the world are being brought back from the dead by dedicated oceanographers and conservationists. “The results are more than just promising; they are beautiful,” says Baruch Rinkevich, a marine biologist at the National Institute of Oceanography in Haifa, Israel. But how can these reefs recover in the face on ongoing global warming? Either global warming has reversed course or the bleaching of reefs wasn't due to global warming in the first place.
In a stunning paper in Science, researchers claim to have reversed the impact of clouds on global climate. It has long been known that low level cloud cover creates a net cooling effect on climate. This new study, which concentrated on a restricted area of the Pacific Ocean, claims that warming oceans reduce low cloud cover letting in more sunlight that further warm the ocean and hence provide a positive feed back that adds to global warming. Based on a warming episode that started in 1978, the article claims that observational analysis showed that clouds act as a positive feedback in this region on decadal time scales. But a cometary on the article in the same issue of Science says that the analysis suggests—but falls short of proving—that clouds are strongly amplifying the warming. If it's true, then almost all climate models have got it wrong.
A recent article in the journal Science has provided a new, detailed climate record for the Medieval Climate Anomaly (MCA), also know as the Medieval Warm Period. It was the most recent pre-industrial warm period, noted in Europe and elsewhere around the globe. The researchers present a 947-year-long multi-decadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. The interesting thing is that the MCA had basically been removed from the climate record by Michael Mann's infamous “hockey stick” history graph that was adopted by the IPCC a decade ago.
With the US storm tossed in the midst of the 2008 Hurricane season the predictable has happened: the United Nations Environment Program (UNEP) has released another report claiming that global warming is boosting the strength and number of storms around the world and in the Atlantic. In a press release dated September 4, UNEP blames climate change for the rising cost of natural disasters around the world.