14 July 2017, Nature Communications, The unprecedented 2015/16 Tasman Sea marine heatwave. The Tasman Sea off southeast Australia exhibited its longest and most intense marine heatwave ever recorded in 2015/16. Here we report on several inter-related aspects of this event: observed characteristics, physical drivers, ecological impacts and the role of climate change. This marine heatwave lasted for 251 days reaching a maximum intensity of 2.9 °C above climatology. The anomalous warming is dominated by anomalous convergence of heat linked to the southward flowing East Australian Current. Ecosystem impacts range from new disease outbreaks in farmed shellfish, mortality of wild molluscs and out-of-range species observations. Global climate models indicate it is very likely to be that the occurrence of an extreme warming event of this duration or intensity in this region is respectively ≥330 times and ≥6.8 times as likely to be due to the influence of anthropogenic climate change. Climate projections indicate that event likelihoods will increase in the future, due to increasing anthropogenic influences. Read More here
Tag Archives: oceans
6 July 2017, Climate Home, The tax-free shipping company that took control of a country’s UN mission. How the tiny, climate-threatened Marshall Islands came to be represented at UN shipping talks by a private company based in Virginia, 11,000 km away. In 2015 Tony de Brum, then foreign minister of the Marshall Islands, came to the International Maritime Organisation (IMO) in London to deliver a simple message: international shipping must decarbonise or be responsible for destroying his country. International shipping could be responsible for nearly a fifth of the world’s carbon emissions by 2050. If the IMO, the branch of the UN that regulates international shipping, failed to set ambitious climate targets, it would be disastrous for low-lying islands like his own, de Brum would say. But when he walked in to the IMO plenary, de Brum found strangers sitting in his country’s place. “I was talking about a Goldilocks situation,” he told Climate Home two years later on the verandah of his bungalow on the Marshallese capital atoll Majuro, a few feet from the lagoon. “We had some difficulty convincing the people who were sitting in our seats, literally, that we were the representatives of the Marshall Islands.” The people de Brum found representing the Marshall Islands were from International Registries Inc. (IRI), a private shipping register headquartered in Reston, Virginia. According to its website, the company provides access to the Marshall Islands flag and a “zero tax jurisdiction that statutorily exempts non-resident domestic corporations from taxation on their income and assets”. Thanks to IRI, the Marshall Islands boasts the second largest fleet of ships in the world and the world’s largest fleet of oil tankers. The company attracts ship owners with the promise of zero corporation tax and no seafarer nationality requirements – the latter allows them to skirt organised labour. The 45,000 offshore companies registered with IRI also benefit from corporate anonymity. De Brum, now climate change ambassador for the Marshall Islands, said he was “appalled” by IRI’s suspicious response to his arrival at the IMO. He did eventually deliver his message. But two years on, the shipping industry remains out of step with the rest of the world on climate change. In 20 years, the IMO has made just one intervention to address carbon emissions: an efficiency index which the International Energy Agency said would only improve efficiency by 1% between 2015 and 2025. A new study by CE Delft found the efficiency of new ships actually got worse in 2016. Read More here
26 June 2017, Washington Post, Sea level rise isn’t just happening, it’s getting faster. In at least the third such study published in the past year, scientists have confirmed seas are rising, and the rate of sea level rise is increasing as time passes — a sobering punchline for coastal communities that are only now beginning to prepare for a troubling future. What was a 2.2 millimeter per year rise in 1993 was a 3.3 millimeter rise in 2014, based on estimates of the mass changes of a number of key components of sea level rise, such as the melting of the Greenland and Antarctic ice sheets, the study in Nature Climate Change found. That’s the difference between 0.86 and 1.29 inches per decade — and the researchers suggest further sea level acceleration could be in store. The chief cause of the acceleration was the melting of the Greenland ice sheet, which went from contributing under 5 percent of all sea level rise in 1993 to contributing over 25 percent in 2014, the study found. The loss of ice in Antarctica and smaller glaciers over the same time period also contributed to quicker sea level rise. The increase in the rate of sea level rise “highlights the importance and urgency of mitigating climate change and formulating coastal adaptation plans to mitigate the impacts of ongoing sea level rise,” write Xianyao Chen of the Ocean University of China and Qingdao National Laboratory of Marine Science and Technology, and colleagues. Chen’s co-authors hailed from institutions in China, Australia and the United States. “We understand why the sea level is accelerating and we’re understanding what the components are contributing,” said Christopher Harig, one of the study’s authors and a researcher at the University of Arizona. Earlier this year, a different group of researchers found sea level rise was only about 1.1 millimeters per year before 1990, whereas in the period between 1993 through 2012 it was 3.1 millimeters per year. NASA, at present, puts the rate of sea level rise at 3.4 millimeters per year. But while the individual estimates differ, the broader picture is that researchers generally agree that the rate of sea level rise is increasing — and that this will have major consequences for coastal regions, which will have less time to adapt if sea level rise acceleration continues. Read More here
29 May 2017, Independent, Great Barrier Reef can no longer be saved, Australian experts concede. The Great Barrier Reef – a canary in the coal mine for global warming – can no longer be saved in its present form partly because of the “extraordinary rapidity” of climate change, experts have conceded. Instead, action should be taken to maintain the World Heritage Site‘s ‘ecological function’ as its ecological health declines, they reportedly recommended. Like coral across the world, the reef has been severely damaged by the warming of the oceans with up to 95 per cent of areas surveyed in 2016 found to have been bleached. Bleaching is not always fatal but a study last year found the “largest die-off of corals ever recorded” with about 67 per cent of shallow water coral found dead in a survey of a 700km stretch. Now experts on a committee set up by the Australian government to improve the health of the reef have revealed that they believe the lesser target of maintaining its “ecological function” is more realistic. In a recent communique, the expert panel said they were “united in their concern about the seriousness of the impacts facing the Reef and concluded that coral bleaching since early 2016 has changed the Reef fundamentally”. “There is great concern about the future of the Reef, and the communities and businesses that depend on it, but hope still remains for maintaining ecological function over the coming decades,” it said. “Members agreed that, in our lifetime and on our watch, substantial areas of the Great Barrier Reef and the surrounding ecosystems are experiencing major long-term damage which may be irreversible unless action is taken now. Read More here