The week that's gone: 25 May 2013

This is a summary of the stories we published in the week ending Saturday 25 May.

Warming climate worries UK farmers

19 May – They are short, have a tough outer skin and are capable of doing a great deal of damage – at least to lawns, grasslands and to cereal crops. Leatherjacket grubs – Tipula oleracea – are the larvae of crane flies, the insects with slender wings and arched legs more commonly known – at least in the United Kingdom – as “daddy-long -legs”. Agriculture experts in Scotland are now suggesting that climate change has been causing recent infestations of the leatherjacket grub in the country, threatening spring-sown cereal crops and grasslands… The infestation of leatherjackets is one of a number of climate change-related threats to agriculture. Experts at SRUC have linked changes in climate with the growth of liver fluke disease – a condition which can kill sheep and cattle. In a recent report it was predicted that an increase in wet, warm winter conditions would likely cause an unprecedented level of the disease in many regions of the UK in future. Scientists have also linked changes in climate to the spread into areas of northern Europe, including the UK, of the blue tongue virus, another disease that can kill cattle and sheep.

Glaciers are melting slowly – but surely

20 May – Forget, for the moment, the Greenland and Antarctic ice sheets: what about all the other stuff? What kind of difference does the melting of glaciers in Scandinavia, or Alaska, or the Himalayas make to the ocean levels? Alex Gardner of Clark University, Massachusetts, and 15 colleagues from the US, Canada and Europe decided to take a closer look: their answer is that shrinking glaciers lost 259 billion tonnes (259 gigatonnes) of mass in the form of meltwater every year between 2003 and 2009, give or take 28 gigatonnes, an amount equal to around 30% of observed sea level rise. This equals the combined losses from the permanent ice sheets that blanket, in layers thousands of metres thick, the two vast land masses of Greenland and Antarctica. The scientists report their findings in the journal Science… the research confirms the big picture: that glaciers are in retreat almost everywhere. And this spells problems in the long run everywhere: glaciers store winter water for summer irrigation, city water supplies and hydroelectric power. They keep rivers navigable, and they maintain mountain ecosystems.

Fish migration reveals ocean warming

21 May – Canadian scientists have devised a new scale for measuring ocean change – the fish. They have used the changing make-up of the global fisheries catch to detect the signature of global warming. In a warming world, fish that find the sea temperatures too hot for comfort could move north or south, away from the tropics, or to deeper and therefore cooler waters. Although oceans are warming, and the chemistry of the seas gradually changing, William Cheung and colleagues at the University of British Columbia report in Nature that… they calculated the temperature preferences of fish species… and then they analysed the annual haul of 990 species across 52 large marine ecosystems between 1970 and 2006. They… came up with a “fish thermometer”, on the argument that, just as changes in the pattern of tree growth rings would expose the climate history of a forest, so changes in the pattern of fish catches would tell them something about ocean temperatures. Their new scale of measurement revealed that overall, oceans were warming at a rate of 0.19°C per decade, and in the non-tropical regions even faster: at 0.23°C per decade.

New York City’s summers may heat up

22 May – If you are a New Yorker, global warming could seriously damage your health. The sweltering summer temperatures of the Big Apple are likely to go on rising through the next six decades, and deaths from heatstroke and other forms of hyperthermia could increase. Scientists from Columbia University report in Nature Climate Change that temperature-related deaths in Manhattan, at the heart of New York, could increase by 20% during the 2020s, and by as much as 90% by the 2080s… Tiantian Li, of the Chinese Centre for Disease Control and Prevention in Beijing, who did his research while at Columbia, and Patrick Kinney and Radley Horton took as their baseline the 1980s, when slightly more Manhattanites were estimated to have died from heat than from cold, and began to look at projections for the future. They took temperature projections from 16 climate models, scaled them to Manhattan, and tested them under two scenarios; one that assumed rapid growth and few limits to carbon dioxide emissions; and another that allowed for slower growth and a decrease in emissions by 2040… In all 32 projections, temperature-related deaths increased, and increased steeply with time.

A cooler century? Wait and see

23 May – Several leading authorities on climate change have given a guarded welcome to research suggesting the Earth may warm more slowly than scientists had expected. An international research team led by Dr Alexander Otto of the Environmental Change Institute (ECI) at the University of Oxford, UK, [suggests]… in the journal Nature Geoscience… the Earth will warm more slowly than expected this century. But… the scientists still believe temperatures will eventually climb to 4°C above pre-industrial levels, well above danger levels. Clive Hamilton, professor of public ethics at Charles Sturt University, Australia… told Climate News Network: “The study should certainly be taken very seriously, although we will need to see over the next year or two how well it stands up to scrutiny…” Dr Geoff Jenkins is the former head of climate change prediction at the UK Met Office’s Hadley Centre for Climate Prediction and Research. He told the Network: “Until we actually understand why the global temperature rise has paused over the last decade – and we don’t yet – it’s still guesswork what the implications are for climate sensitivity and hence the future projections.”

Royal goings-on freeze out climate

23 May − Prince Charles, heir to the British throne, made one of his strongest speeches yet on the dangers of a warming planet when he warned this month that climate change is “the greatest risk we have ever faced”. Action must be taken now, the Prince said, because the risk of doing nothing is “too great”. It is therefore a little ironic to look at the latest results from a study by the monitoring organisation Media Matters for America and find that the goings-on of the British royal family – but not their comments on the dire state of the planet – feature far more prominently on the major US networks than any topic related to climate change. “Even during the warmest year on record in the US, the nightly news programmes combined devoted only 12 full segments to climate change,” Media Matters reports. “By contrast, these programmes dedicated over seven times more coverage to the royals in 2012”… Earlier this month, as scientists announced the amount of CO² in the atmosphere had gone beyond 400 parts per million, two of the major US news programmes ignored the story, preferring instead to cover the visit to the country of Prince Harry, the younger son of Prince Charles.

Hurricane warning is linked to climate

25 May – US scientists have warned Americans that they can expect more and perhaps fiercer hurricanes than usual from the Atlantic Ocean this year. The Climate Prediction Center at the National Oceanic and Atmospheric Administration, NOAA, is forecasting ”an active or extremely active season” for hurricanes in 2013. It says several climatic factors are expected to combine this year to cause the unusually high level of hurricane activity. One of these is the higher than usual sea temperatures. For the six-month hurricane season, which begins on 1 June, NOAA’s Atlantic Hurricane Season Outlook says there is a 70% likelihood of 13 to 20 named storms, which have winds of 39 mph or higher. Of these storms, NOAA says, 7 to 11 could become hurricanes, with winds of 74 mph or higher, including 3 to 6 major hurricanes, where wind speeds will reach 111 mph or more. NOAA says: “These ranges are well above the seasonal average of 12 named storms, 6 hurricanes and 3 major hurricanes.”