Climate & Climate Change

In amongst an article that contains yet another straw-man attack on cosmic rays via the BBC, there is something more interesting reported from the European Geosciences Union (EGU) meeting.

In periods of relatively intense particle activity, some areas of the Earth’s surface in both the Arctic and Antarctic are warmer while others become colder, showing differences of up to 2C or 3C compared to the long-term averages.

In periods of unusually low particle activity, the patterns are reversed.

The mechanism appears to be redistributing heat across the polar regions; there is no evidence for any overall warming or cooling, Dr Seppala added, nor that the scale of the effect has changed over time.

“The results were amazing, and I think it’s something significant that we have to take into account,” commented Katje Matthes from the Free University of Berlin, who chaired the EGU session which saw the new data presented.

“I think it’s rather a local effect,” she added, “and I don’t think it has a big impact on global temperatures.”

Read more here:

http://news.bbc.co.uk/1/hi/sci/tech/7352667.stm

There are several interesting climate related studies in this week’s Science magazine.

Greenland Ice Slipping Away but Not All That Quickly

Almost 6 years ago, a paper in Science warned of an unheralded environmental peril. Melted snow and ice seemed to be reaching the base of the great Greenland ice sheet, lubricating it and accelerating the sheet’s slide toward oblivion in the sea, where it was raising sea level worldwide (12 July 2002, p. 218).

A new study has confirmed that meltwater reaches the ice sheet’s base and does indeed speed the ice’s seaward flow. The good news is that the process is more leisurely than many climate scientists had feared. Glaciologist Richard Alley of Pennsylvania State University in State College says, “It matters, but it’s not huge.” The finding should ease concerns that Greenland ice could raise sea level a disastrous meter or more by the end of the century.

Read more at PHYSORG.com: Lakes of meltwater can crack Greenland’s ice and contribute to faster ice sheet flow

Coral Adaptation in the Face of Climate Change

IN THEIR REVIEW, “CORAL REEFS UNDER RAPID CLIMATE CHANGE and ocean acidification” (14 December 2007, p. 1737), O. Hoegh- Guldberg et al. present future reef scenarios that range from coral-dominated communities to rapidly eroding rubble banks. Notably, none of their scenarios considers the capacity for corals to adapt. The authors dismiss adaptation because “[r]eef-building corals have relatively long generation times and low genetic diversity, making or slow rates of adaptation [relative to rates of change].” We think the possibility of adaptation deserves a second look.

In the absence of longterm demographic studies to detect temporal trends in life history traits, predicting rates of adaptation, and whether they will be exceeded by rates of environmental change, is pure speculation. Indeed, where such data are available for terrestrial organisms they demonstrate that contemporary evolution in response to climate change is possible (7).

There’s another coral story in The Herald Sun: Scientists find corals flourishing on Bikini Atoll

Phytoplankton Calcification in a High-CO2 World

Ocean acidification in response to rising atmospheric CO2 partial pressures is widely expected to reduce calcification by marine organisms. From the mid-Mesozoic, coccolithophores have been major calcium carbonate producers in the world’s oceans, today accounting for about a third of the total marine CaCO3 production. Here, we present laboratory evidence that calcification and net primary production in the coccolithophore species Emiliania huxleyi are significantly increased by high CO2 partial pressures. Field evidence from the deep ocean is consistent with these laboratory conclusions, indicating that over the past 220 years there has been a 40% increase in average coccolith mass. Our findings show that coccolithophores are already responding and will probably continue to respond to rising atmospheric CO2 partial pressures, which has important implications for biogeochemical modeling of future oceans and climate.

Read more at Dot Earth: Some Plankton Thrive With More CO2

According to Nature, the fifth Intergovernmental Panel on Climate Change (IPCC) report will be out by 2014, IPCC chair Rajendra Pachauri announced last week in Budapest. The report from the first working group will come out in 2013, however, so that its findings can be incorporated more fully into the reports from the second and third working groups.

Of course, by 2014 we will have passed the Hansen/Blair tipping points and there will be no summer sea ice in the Arctic, according to Al Gore.

The IPCC also released the TECHNICAL PAPER ON CLIMATE CHANGE AND WATER in Budapest, 9th – 10th April.

We can also look forward to a special report on renewable energy by 2010.

For 9550 years a Spruce has survived in the mountains on the Swedish landscape, Dalarna, bordering Norway. This means that this tree is the oldest known tree in the world.

About 20 Spruces have been found in the mountain area that are over 8000 years old. They have survived climate changes due to their ability to shrink to bushes in cold weather and standing / growing erect in warmer weather.

Evidence indicates that the Spruce will be THE species that will give us the most information about climate change, said Professor Leif Kullman from Sweden.

Check out the story (if you speak Swedish) and the photo of the old tree.

Let’s hope Michael Mann doesn’t turn it into a Hockey Stick!

Thanks to Ann Novek of Sweden for this very interesting story.

UPDATE

The Daily Telegraph: World’s oldest tree discovered in Sweden

The tree has rewritten the history of the climate in the region, revealing that it was much warmer at that time and the ice had disappeared earlier than thought.

It had been thought that this region was still in the grip of the ice age but the tree shows it was much warmer, even than today.

The summers 9,500 years ago were warmer than today, though there has been a rapid recent rise as a result of climate change that means modern climate is rapidly catching up.

There is very little justification for asserting that global warming has gone away over the past ten years, not least because the linear trend in globally-averaged annual mean temperatures (the standard yardstick) over the period 1998-2007 remains upward. While 1998 was the world’s warmest year in the surface-based instrumental record up to that point in time, 2005 was equally warm and in some data sets surpassed 1998. A substantial contribution to the record warmth of 1998 came from the very strong El Niño of 1997/98 and, when the annual data are adjusted for this short-term effect (to take out El Niño’s warming influence), the warming trend is even more obvious.

from Waiting for Global Cooling by Fawcett and Jones

Because of the year-to-year variations in globally-averaged annual mean temperatures, about ten years are required for an underlying trend to emerge from the “noise” of those year-toyear fluctuations. Hence, the fact that 2006 and 2007 were cooler than 2005, is nowhere near enough data to clearly establish a cooling trend.

“Global warming stopped in 1998. Global temperatures have remained static since then, in spite of increasing concentrations of greenhouse gasses in the atmosphere. Global temperatures have cooled since 1998. Because 2006 and 2007 were cooler than 2005, a global cooling trend has established itself.”

All these statements, and variations on them, have been confidently asserted in the international and Australian media in the past year or so, but the data do not support them.

Read more here: http://www.aussmc.org/documents/waiting-for-global-cooling.pdf

Article via Luke Walker. Thanks.

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Keywords: National Climate Centre, Australian Bureau of Meteorology, April 2008, David Jones, Robert Fawcett, warming, cooling, global temperatures, Australian Science Media Centre.

I have recently made a superficial analysis of temperature trends at York, Western Australia, the nearest weather station to my place at Gwambygine. York is approximately 100 kms inland from the Indian Ocean, on about latitude 32.

The weather data for York is interesting for two reasons: (i) there has been a continuously reporting weather station here since 1877; and (ii) in 1996 the station was relocated from the rear of the Post Office in the centre of town to a farm paddock two kilometres away. The Bureau of Meteorology (BoM) publishes separate weather data for each site. Thus it is possible to compare mean daily max and min temperatures for the period 1877-1995 with those for the period 1996-2006. (The 2007 data has not yet been published).

I found that the mean daily maximum temperature for the period 1996-2007 was 0.6 degrees warmer than the mean daily temperature over the previous 119 years. However, the mean daily minimum temperature for the decade 1996-2007 was 1.0 degree cooler than for the previous 119 years. This suggests that on average, overall, York has been marginally colder since 1996. In any case there is no evidence of “catastrophic warming” for this site.

Without the actual data (which is not freely available), it is impossible to test the statistical significance of these differences. In any case, I consider it more likely that any differences are due to the relocation of the weather station. The old Post Office site was surrounded by high stone walls and heat-absorbing/retaining brick buildings and car parks, whereas the new site is beyond the town in an open paddock.

I wrote to the BoM for comments on my analysis. In reply they presented a graph showing annual maximum and minimum temperature trends with a running 11-year mean combining both weather staions for York for the period 1910 to 2006. These reveal a roughly 1 degree increase in annual maximum temperature over the last 96 years and a roughly 0.3 degree increase in annual minimum temperature.

I wrote back to the BoM and asked why they chose 1910 as the starting point for their analysis. Their interesting reply was:

“A change in the type of thermometer shelter used at many Australian observation sites in the early 20th century resulted in a sudden drop in recorded temperatures which is entirely spurious. It is for this reason that these early data (pre-1910) are currently not used by the Bureau in monitoring climate change.”

I would be interested if anyone could refer me to an authoritative paper on the history, quality and anomalies in Australian weather records and the influence of the re-location of weather stations. I am aware, for example, that the Perth Western Australia weather station has been re-located at least three times over the years, each time to an area with an obviously different microclimate. How is this taken into account in determining real long term trends? And are there other key sites in the historical record for which temperature records have been artificially influenced by changes to thermometer shelters, or other technical aspects.

Roger Underwood is a former General Manager of the Department of Conservation and Land Management (CALM) in Western Australia, a regional and district manager, a research manager and bushfire specialist. Roger currently directs a consultancy practice with a focus on bushfire management. He lives in Perth, Western Australia.

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‘Déjà Vu on the ABC’ by Roger Underwood was voted one of the best Australian blog posts of 2006.