A synthesis report for policy makers. Ecosystems are essential to our well-being and prosperity as they provide us with food, clean air and fresh water. Ecosystems also represent an exceptional source of outdoor recreation opportunities. The functions performed by ecosystems that increase our well-being are called ecosystem services.

Coral reefs face severe challenges even if global warming is restricted to the 2 degrees Celsius commonly perceived as safe for many natural and man-made systems. Warmer sea surface temperatures are likely to trigger more frequent and more intense mass coral bleaching events. Only under a scenario with strong action on mitigating greenhouse-gas emissions and the assumption that corals can adapt at extremely rapid rates, could two thirds of them be safe, shows a study now published in Nature Climate Change. Otherwise all coral reefs are expected to be subject to severe degradation.

Natural catastrophe losses were relatively moderate in the first six months of 2012. Overall global losses up to the end of June were in the order of US$ 26bn, of which approximately US$ 12bn was insured. The loss statistics were dominated by natural hazard events in the USA where, due to tornado outbreaks and wildfires, nearly 85% of total insured losses worldwide were incurred.

The CO2 concentration in the atmosphere is causing the acidity of the oceans to increase. Scientists at ETH Zurich have investigated how the acidity along the west coast of the USA will develop until the year 2050. They expect considerable changes in the ecosystem.

Sea levels around the world can be expected to rise by several metres in coming centuries, if global warming carries on. Even if global warming is limited to 2 degrees Celsius, global-mean sea level could continue to rise, reaching between 1.5 and 4 metres above present-day levels by the year 2300, with the best estimate being at 2.7 metres, according to a study just published in Nature Climate Change. However, emissions reductions that allow warming to drop below 1.5 degrees Celsius could limit the rise strongly.

The influence of the ground beneath us on the air around us could be greater than scientists had previously thought, according to new research that links the long-ago proliferation of oxygen in Earth's atmosphere to a sudden change in the inner workings of our planet.

We investigated the mechanisms leading to rapid death of corals when exposed to runoff and resuspended sediments, postulating that the killing was microbially mediated.

The 2012 biodiversity barometer finds that 76% of all respondents from around the globe were aware of sustainable development, 64% of biodiversity. Of the top 100 beauty companies in the world, 54 mentioned sustainability in their reporting and website, while 31 referred to biodiversity.

Intricate, often invisible chains of life are threatened with extinction around the world. A new study quantifies one of the longest such chains ever documented. By Rob Jordan

The Filchner-Ronne Ice Shelf fringing the Weddell Sea, Antarctica, may start to melt rapidly in this century and no longer act as a barrier for  ice streams draining the Antarctic Ice Sheet. These predictions are made by climate researchers of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association in the coming issue of the British science magazine “Nature“. They refute the widespread assumption that ice shelves in the Weddell Sea would not be affected by the direct influences of global warming due to the peripheral location of the Sea.