Tag: sea level

Seven feet high and rising

Plan for two metres sea level rise this century. That’s the message from Rob Young and Orrin Pilkey in a Yale Environment article published today.

“This number is not a prediction. But we believe that seven feet is the most prudent, conservative long-term planning guideline for coastal cities and communities, especially for the siting of major infrastructure; a number of academic studies examining recent ice sheet dynamics have suggested that an increase of seven feet or more is not only possible, but likely. Certainly, no one should be expecting less than a three-foot rise in sea level this century.”

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Wade in the water

Estimates of the sea level rise that will result from continued global warming continue to increase, with two recent papers adding more evidence that the IPCC AR4 projections were unrealistically low. The rise this century could be as high as 1.9 metres, and the long term response to a warming limited to 2ºC could be 6 – 9 metres the studies suggest. There are also signs that New Zealand planners are beginning to take the issue seriously, with Nelson and Wellington both considering the impacts of sea level rises of over a metre.

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More than a number

If you want to know what’s happening on a stockmarket, the first place to look is at the relevant index — the Footsie (FTSE) for the London Stock Exchange, or the Dow Jones for Wall Street. Those indices aggregate all the price movements over a day into one handy number, to give a quick overview of how the market’s behaving. Now a group of scientists working for the International Geosphere-Biosphere Programme (IGBP) have compiled a Climate Change Index (CCI) to provide the same service for the evidence of climate change. The CCI was launched in Copenhagen yesterday. The video above describes the approach they’ve used, and the “ladder” graphic below shows how the CCI has moved over the last 30 years:

CCI_steps_bigger.jpg

The CCI tracks changes in global temperature, atmospheric CO2, Arctic sea ice, and sea level. An increase in the CCI shows a move away from a stable climate. Over the last 30 years the cumulative shift has been 574 points — in the wrong direction. The IGBP team point out that the CCI responds to global cooling events such as the Pinatubo and El Chichon eruptions, but they are also looking at adding other indicators to the index including land-use, fisheries exploitation, population, fire and extreme events. They are planning to update the index every year, and to backdate it to periods before 1980.

[The Drifters]

Antarctic science review: greening and melting

The first comprehensive scientific review of our understanding of Antarctic climate and the way that it’s changing was published in the UK earlier this week [ScienceDaily]. The Antarctic Climate Change and the Environment report (a free download), prepared by the Scientific Committee on Antarctic Research (SCAR), points to ten key findings [PDF]:

  • For the last 30 years, the ozone hole has shielded the bulk of the Antarctic from the effects of “global warming”
  • The Southern Ocean is warming – the ecosystem will change
  • There has been a rapid expansion of plant communities across the Antarctic Peninsula
  • Parts of the Antarctic are losing ice at a rapid rate
  • Sea ice has increased in extent over the last 30 years as a result of the ozone hole
  • Paleoclimate studies in Antarctica show that the current shock to global climate is unusual
  • Marine ecosystem components, such as krill and penguins, linked to the sea ice show a clear response to climate change
  • Assuming a doubling of greenhouse gas concentrations over the next century, Antarctica is expected to warm by around 3ºC
  • West Antarctica could make a major contribution to sea level rise over the next century
  • Improved representation of polar processes is needed in models to produce better predictions

The full report weighs in at 526 pages [20MB PDF] and is a superb overview of the state of our knowledge. It’s not an easy read, but in the manner of the IPCC reports is comprehensive and carefully referenced, with lots of illustrations of what’s going on. Recommended. The BBC has good coverage of the sea level implications, Stuff picks up on the “greening” aspect, and the Guardian notes that warming will accelerate as the ozone hole heals.

Climate compendium: important insights

Compendium“The Climate Change Science Compendium is a wake-up call. The time for hesitation is over”. So wrote Ban Ki-moon in his foreword to this UN Environment Programme publication released last week. The publication is a review of how climate science has evolved since the Fourth Assessment Report (AR4), and is based on some 400 major scientific contributions in the peer-reviewed literature or from research institutions since the deadline for inclusion in AR4 three years ago. It appears in response to the request of many governments and stakeholders for a snapshot update. Achim Steiner, the Executive Director of the Environment Programme makes it very clear that it doesn’t replace the painstaking rigour of an IPCC process, but he hopes it will provide important insights into the rapidly developing and fast moving realm of climate science so that the choices made by leaders in Copenhagen in December are informed by the best and the latest research available to the international community.

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