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Increasing sea surface temperatures are imperilling coral reef ecosystems say Australian marine and climate scientists. A new scientific paper reveals that atmospheric warming of 2 degrees celsius is too much for nearly all the world's coral reef ecosystems, including the Great Barrier Reef. The scientists argue that to preserve greater than 10 per cent of coral reefs worldwide would require limiting global warming to below 1.5 °C. This equates to the goal of reducing carbon in the atmosphere to 350ppm, rather than a 2 degree rise or 450ppm that the UN Framwework Convention on Climate Change has adopted as the safe limit at several meetings.

Atmospheric concentration of CO2 currently stands at 392.41ppm. With current pledged reduction in emissions we are heading for 4.4 °C of warming by the end of the century according to the Climate Scoreboard.

Related: The True Cost of Australia's Coal Boom | Greenpeace report: Boom Goes the Reef: Australia's coal export boom and the industrialisation of the Great Barrier Reef (PDF) | The Conversation: - Climate change guardrail too hot for coral reefs?

An international study led by CSIRO oceanographer Dr Wenju Cai has identified that global warming is causing shifts in the rain band of the South Pacific Convergence Zone causing an increase in extreme weather across the island nation states of the South Pacific. The result of the movement causes drought and higher prevalence of forest fire in some areas while other islands experience extreme floods and increased frequency of tropical cyclones.

"Due to its strong rainfall gradient, a small displacement in the [South Pacific Convergence Zone] SPCZ's position causes drastic changes to hydroclimatic conditions and the frequency of extreme weather events such as droughts, floods and tropical cyclones experienced by vulnerable island countries in the region." says the paper.

A new study by NOAA - the US National Oceanic and Atmospheric Administration - has highlighted that climate change is a major contributor to more frequent Mediterranean droughts. According to the study in the last 20 years, 10 of the driest 12 winters have taken place in the lands surrounding the Mediterranean Sea. Water security, food security, and increasing wildfire frequency and intensity has the potential to destabilize the region producing conflicts over use of increasingly scarce water resources.

"The magnitude and frequency of the drying that has occurred is too great to be explained by natural variability alone,” said Martin Hoerling, Ph.D. of NOAA’s Earth System Research Laboratory in Boulder, Colorado, lead author of a paper published online in the Journal of Climate this month. “This is not encouraging news for a region that already experiences water stress, because it implies natural variability alone is unlikely to return the region’s climate to normal.”