Global warming and the future of New Zealand
This column was published in the Waikato Times on July 14
Could New Zealand agriculture be part of the solution to climate change? We know all too well that it is part of the problem – and that’s not an accusation, by the way, just a recognition. But problems are there to be tackled, and what is called carbon farming looks like one way in which agriculture can substantially contribute to climate change mitigation and at the same time improve the soils on which it depends.
Elizabeth Kolbert recently interviewed Jane Lubchenco (pictured), appointed by President Obama as head of the National Oceanic and Atmospheric Administration. Kolbert comments that when Lubchenco was appointed the reaction among climate scientists was an almost audible sigh of relief. During the Bush administration the work of NOAA staff was frequently ignored or even suppressed, and Lubchenco’s appointment was seen as a sign of the new administration’s resolve to finally take NOAA’s work seriously.
The earlier sections of the Copenhagen congress synthesis report are, in this final section, summed up in forthright terms: “business-as-usual is deadâ€. Small marginal changes to the way society currently operates socio-economically and technologically won’t keep climate change within the 2 degree guardrail. Section 5 of the report affirmed that the tools are available for the transformation needed. Section 6 focuses on how societies can be engaged in making the transition to a more sustainable future. This has to be done on many scales, from individual to institutional and governmental, and at many levels, from changes in everyday behaviour to a reexamination of core values, beliefs and worldviews. It lies in the domain of the humanities and social sciences, which were represented at the congress.
New analysis of Icesat data by a NASA team headed by Ron Kwok shows that from 2004 to 2008 Arctic winter sea ice “thinned dramatically”. Icesat measures the “freeboard” of the sea ice, the amount above water level. The graph below shows the extent of the decline, which is most marked in multi-year ice (ice that survives more than one summer).
[Click image for bigger version]
In 2003, 62 percent of the Arctic’s total ice volume was stored in multi-year ice, with 38 percent stored in first-year seasonal ice. By 2008, 68 percent of the total ice volume was first-year ice, with 32 percent multi-year.
The information on ice thickness is critical to understanding what’s going on in the Arctic, as Kwok notes:
“Ice volume allows us to calculate annual ice production and gives us an inventory of the freshwater and total ice mass stored in Arctic sea ice,” said Kwok. “Even in years when the overall extent of sea ice remains stable or grows slightly, the thickness and volume of the ice cover is continuing to decline, making the ice more vulnerable to continued shrinkage. Our data will help scientists better understand how fast the volume of Arctic ice is decreasing and how soon we might see a nearly ice-free Arctic in the summer.”
NASA also provide some very nice visualisations of the data: animations of the changes in autumn and winter ice thickness as well as still images. Well worth a look. For more about NASA’s work on thickness, check this earlier post.
Also well worth checking out: The Standard posts a report a lecture about Andrill and the West Antarctic ice sheet by Prof Tim Naish. Earlier in the week, the Herald also reported on a lecture by Prof Peter Barrett that covered similar ground. I’m hoping to persuade the good professors to provide more detail here sometime soon…
The National Snow and Ice Data Centre (NSIDC) has just published its July sea ice news update on the state of the Arctic and the progress of the melt season. Under the heading Melt season in high gear, it gives an overview of June events, and the conditions at the start of the period of most rapid melt. Most interesting is their comment that weather patterns over the month were similar to those of 2007, when the record minimum was set:
This contrast between high and low pressure is broadly similar to the atmospheric circulation pattern that set up in 2007. In 2007, that pattern contributed to a significantly accelerated decline in ice extent during July, and a record minimum low in September. Will the same acceleration in ice melt occur this year? If so, a new record low minimum extent becomes more likely. So far, an acceleration has not been observed.
On the other hand, a peek at the IJIS graph shows that 2009 (red) has dipped below last year at the same time, and Cryosphere Today is showing large areas of ice break up (click on the thumbnail above for a larger version). CT’s metric (area, not extent) is also showing a steep decline. No sign of the fat lady yet…
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