10 May, The Guardian, Headlines ‘exaggerated’ climate link to sinking of Pacific islands. Links between climate change and the sinking of five islands in the Pacific Ocean have been exaggerated, the author of a widely reported new study has said. The report, published on Friday, tracked the shapeshifting of 33 reef islands in the Solomon Islands between 1947 and 2014. It found that five had been washed away completely and six more had been severely eroded. The study blamed the loss on a combination of sea-level rise and high wave energy. Many media outlets, including the Guardian, jumped to the conclusion that the islands were lost to climate change. But this largely misinterprets the science, according to the study’s author, Dr Simon Albert. “All these headlines are certainly pushing things a bit towards the ‘climate change has made islands vanish’ angle. I would prefer slightly more moderate titles that focus on sea-level rise being the driver rather than simply ‘climate change’,” Albert told the Guardian. The major misunderstanding stems from the conflation of sea-level rise with climate change. As a scientifically robust and potentially destructive articulation of climate change, sea-level rise has become almost synonymous with the warming of the planet. However, as Albert’s paper points out, the ocean has been rising in the Solomon Islands at 7mm per year, more than double the global average. Since the 1990s, trade winds in the Pacific have been particularly intense. This has been driven partly by global warming and partly by climatic cycles – in particular the Pacific Decadal Oscillation. “These trade winds have basically pushed water up into western Pacific and have driven these exceptionally high rates of [sea-level rise] in the Solomons,” said Albert. “The trade winds are partly a natural cycle but also the recent intensification is related to atmospheric warming.” The proportion of the extra rise driven by climate change was not considered by Albert’s study. Read More here
Tag Archives: oceans
7 May 2016, The Conversation, Sea-level rise has claimed five whole islands in the Pacific: first scientific evidence. Sea-level rise, erosion and coastal flooding are some of the greatest challenges facing humanity from climate change. Recently at least five reef islands in the remote Solomon Islands have been lost completely to sea-level rise and coastal erosion, and a further six islands have been severely eroded. These islands lost to the sea range in size from one to five hectares. They supported dense tropical vegetation that was at least 300 years old. Nuatambu Island, home to 25 families, has lost more than half of its habitable area, with 11 houses washed into the sea since 2011. This is the first scientific evidence, published in Environmental Research Letters, that confirms the numerous anecdotal accounts from across the Pacific of the dramatic impacts of climate change on coastlines and people. A warning for the world Previous studies examining the risk of coastal inundation in the Pacific region have found that islands can actually keep pace with sea-level riseand sometimes even expand. However, these studies have been conducted in areas of the Pacific with rates of sea level rise of 3-5 mm per year – broadly in line with the global average of 3 mm per year. For the past 20 years, the Solomon Islands have been a hotspot for sea-level rise. Here the sea has risen at almost three times the global average, around 7-10 mm per year since 1993. This higher local rate is partly the result of natural climate variability. These higher rates are in line with what we can expect across much of the Pacific in the second half of this century as a result of human-induced sea-level rise. Many areas will experience long-term rates of sea-level rise similar to that already experienced in Solomon Islands in all but the very lowest-emission scenarios. Read More here
7 April 2016, Carbon Brief, Analysis: the ‘highly unusual’ behaviour of Arctic sea ice in 2016. The decline of Arctic sea ice is already setting records in 2016, with the winter peak in March clocking in as the lowest since satellite records began, scientists say. A new and fuller summary of this year’s Arctic winter by the US National Snow and Ice Data Centre (NSIDC) confirms the preliminary announcement last week that sea icereached its annual maximum extent on 24 March this year. Covering an area of 14.52m square kilometers, this year’s peak winter extent is a shade smaller than the previous record low set in 2015. But the new NSIDC report adds a lot more detail about what it calls a “highly unusual” and “most interesting” Arctic winter. With abnormally warm conditions right across the Arctic, some regions experienced temperatures 4-8C higher than average. While this meant slower ice growth in some places, in others it caused a dramatic thinning by 30cm in one week, according to early model results. Reaching a peak Arctic sea ice ebbs and flows with the seasons, reaching a maximum extent for the year in February or March and a minimum in September, at the end of the summer melt period. This year, scientists were still waiting expectantly at the end of March, explains the NSIDC report: “Very early in the month, extent declined, raising anticipation that an early maximum had been reached. However, after a period of little change, extent slowly rose again, reaching the seasonal maximum on March 24.” As late as a week ago, scientists still hadn’t ruled out the possibility of a late season surge. But sea ice extent has dropped off quite a bit since then, suggesting the peak has been and gone. You can see this year’s sea ice behaviour in the graph below from NSIDC, which shows sea ice extent over the 2015/6 winter (blue line) up to 3 April compared to previous years. Read More here
5 April 2016, The Conversation, This summer’s sea temperatures were the hottest on record for Australia: here’s why. The summer of 2015-2016 was one of the hottest on record in Australia. But it has also been hot in the waters surrounding the nation: the hottest summer on record, in fact.
Graph above: Difference in summer sea surface temperatures for the Australian region relative to the average period 1961-1990.Australian Bureau of Meteorology While summer on land has been dominated by significant warm spells, bushfires, and dryness, there is a bigger problem looming in the oceans around Australia. This summer has outstripped long-term sea surface temperature records that extend back to the 1950s. We have seen warm surface temperatures all around Australia and across most of the Pacific and Indian oceans, with particularly warm temperatures in the southeast and northern Australian regions. Read More here