Tag: Antarctica

Sharpening Antarctica’s image

I like Google Earth. I like looking down on my neighbours to see what’s going on behind their shelter belts, and because I like monitoring what’s going on at the poles, I have the National Snow & Ice Data Centre’s overlay switched on most of the time. It shows current sea ice extent, snow cover and so on. But when I swoop over Antarctica, the underlying images provided by Google are rather disappointing – low resolution and distorted. I was therefore very pleased to discover that a collaboration between NASA, the US Geological Survey, the National Science Foundation and the British Antarctic Survey has created a new map of the continent based on Landsat imagery. From NASA’s press release:

The map is a realistic, nearly cloudless satellite view of the continent at a resolution 10 times greater than ever before with images captured by the NASA-built Landsat 7 satellite. With the unprecedented ability to see features half the size of a basketball court, the mosaic offers the most geographically accurate, true-color, high-resolution views of Antarctica possible.

You can play with the map at the USGS site, but the interface is rather clunky. However, there are hints that the new map will be available for Google Earth before long. Can’t wait….

Going up

How much will sea level rise over this century? “Don’t know” is a good answer. “Not much” is looking like a bad answer that’s getting worse by the month. Last week a group of Northland Conservation Corps workers rode on a hikoi along Ninety Mile Beach to draw attention to the issue:

Tutor Mike Wikitera and his team erected five signs marking predicted sea level rises by 2030. The group, who rode horses to avoid adding to greenhouse gas emissions, erected the first sign at Shipwrecks Bay and placed the last one at Waipapakauri beach on October 30.

But what are the “likely levels” by 2030? The IPCC’s latest report projects between 18cm and 59cm by the end of the century, but only by excluding a very big unknown – how much ice will melt in Greenland and Antarctica. As more evidence of dramatic melt in Greenland arrives, it’s getting increasingly difficult to rule out multi metre rises. The latest number comes from Professor David Vaughan of the British Antarctic Survey, quoted in the Daily Telegraph [UK]:

Prof Vaughan says the main message is not to panic – the effects of melting will be gradual, in the order of three metres per century if the evidence of the past 20,000 years is anything to go by.

Three metres per century? That’s towards the top end of current speculation. 30cm every ten years, ten times the current rate, compares with 17cm over the last century. Prof Vaughan’s right about panic. It’s not a good option, but extreme concern is certainly justified. For some dramatic pictures of what might happen, check out this Greenpeace report on climate change impacts on Spain, timed to coincide with the IPCC meeting in Valencia to ratify the AR4 synthesis report. To see what 3m might mean for NZ, go here and zoom in on your favourite bit of beachfront property. NIWA’s current advice to local government is to allow for 50cm by 2100. That’s in need of considerable upward revision.

Meanwhile, the impact of sea level rise is not just high tides and wet feet. Salt water intrusion into fresh water coastal aquifers can be bad news for agriculture and drinking water – and the problem may be worse than previously thought, according a new study reported by Science Daily. The BBC covers one of the areas at most risk – Bangladesh – in a new series, documenting a boat journey through the country.

Float on…

A big float story slipped under the HT radar a month ago. Luckily I noticed the NZ connection in a recent release from the Scripps Institute in California – designers and builders of many of the Argo float network – and so I bring you news of the completion of this ocean monitoring system and the big role played by NIWA and its research ship, the Kaharoa, in deploying the floats. Better late than never…

Continue reading “Float on…”

Tuesday linkfest

Labour weekend means just that, chez Hot Topic. Catching up with farm work, planting the vege garden, getting a sore back – all in a weekend’s work. But climate change waits for no man, so here’s a compendium of stuff that caught my attention over the last few days.

  • Contact Energy has announced plans for a huge – 218 turbine, 650MW – wind farm called Hauauru ma raki, to be built on a remote site south of Port Waikato. NZ turbine builder Windflow Technology has announced plans for new models designed to work in India and China, and Meridian has sent wind experts to Scott Base in Antarctica to advise on building wind turbines to reduce fossil fuel requirements. According to Stuff, they think it could be easier than building in Wellington.
  • Still more on the Arctic summer: the NSIDC updates its coverage with some excellent animations, while Cryosphere Today adds an archive of maps of atmospheric conditions over the summer, and introduces a web app that allows iPhone users to monitor sea ice conditions. Another reason why I want one. Technology Review visits Greenland to meet the teams measuring the melt, and down south, satellites spot a huge berg breaking off the Pine Island Glacier.
  • On the roof of the world, the Nepali Times reports Kiwi guides describing how the disappearance of ice on the planet’s biggest mountains is changing the climbs.
  • Two more good articles from TR: Fixing the Power Grid describes how big batteries (capable of supplying 1MW+ for hours at a time) can provide back up for grid problems, and Tiny Solar Cells looks at nanowire solar cells made by a team at Harvard.
  • Carbon emissions from shipping could be as much as twice those from aviation, according to a report from Intertanko. Strong growth in trade has driven emissions to 1.2 billion tonnes oer annum. Meanwhile, the Herald reports on aviation’s attempts to be seen to be more climate friendly – and Richard Branson’s efforts to beat Air New Zealand to the first use of biofuels in jets.
  • CO2 absorption in the Atlantic has nosedived, adding to concerns that the ocean carbon sink may be reducing – leaving more of our emissions in the atmosphere [University of East Anglia].
  • Coral reef specialists have issued a call to action on the impact of climate change: “We call on all societies and governments to immediately and substantially reduce greenhouse gas emissions. Without targeted reductions, the ongoing damage to coral reefs from global warming will soon be irreversible.”
  • The Daily Telegraph [UK] is in the process of becoming enthusiastically green. Latest evidence is a nifty widget – the Telegraph Earth Pulse – which monitors climate and general environment news.
  • A dairy farm can produce as much sewage as a small town (see North & South current issue), but worms can turn it all into mellow compost according to US researchers.
  • It looks like a “three-wheeled technicolour shoehorn”, but the No More Gas will do 75 mph and has a range of 30 miles. OK for getting around town, but I’d still prefer a Tesla Roadster…
  • The financial word is getting the climate message: Deutsche Bank thinks that efforts to combat climate change will drive an investment “megatrend”, Morgan Stanley estimates that global sales of wind, solar and geothermal power and biofuels could be US$1 trillion a year by 2030, and HSBC is launching a climate change investment fund for investors who want to track companies active in the field.
  • HT tends to steer clear of dsicussing peak oil, but the Guardian [UK] covers a new report that claims that we passed peak oil last year, and that global oil production will be halved by 2030. Adds a certain piquancy to energy strategy…

Time to buy new wellies

WellieRegular readers will know that I’ve been keeping a close eye on this year’s Arctic summer, and the record minimum sea ice extent reached last month (nice NASA picture here). The ice area is increasing now, but is still about 1m km2 below the same time last year. I might have to increase my bet… If all the summer Arctic sea ice disappears quickly, it won’t have any impact on sea level, but if the ice on land – mountain glaciers and the great ice sheets of Greenland and the Antarctic – melts, sea level will rise. During the last interglacial, about 125,000 years ago, global temperature was a degree or two warmer than today and sea level was about 5m higher. Some of that extra water came from Greenland and Antarctica.

When I was writing Hot Topic, the latest information suggested that Greenland was losing about 200 km3 (cubic kilometres) of ice every year, and Antarctica about 150 km3 (HT, p45). But time goes on, and the world warms. A study to be published in Geophysical Research Letters suggests that the glaciers of southeast Greenland are now losing 300 km3 of ice per year, a 400% increase in melt rate since 2004. AFP reports:

“Until 2004, the glacier mass in the southeastern part of the island lost about 50 to 100 cubic kilometres (12 to 24 cubic miles) per year. After this date, the melting rate accelerated to 300 cubic kilometres per year. It’s a jump of 400 percent, which is very worrying,” National Space Center head researcher and project chief Abbas Khan told AFP. […] The measurements indicated that the mountains hugging glaciers in the southeastern part of Greenland rose four to five centimetres (1.5 to two inches) per year, and that the banks of the glaciers thinned 100 metres per year.

Continue reading “Time to buy new wellies”