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Luke Walker

Looking for AGW in a Sea of Natural Variability: Declining Rainfall in SW Western Australia (Part 2) – A Note from Luke Walker

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Finding anthropogenic global warming (AGW) shapes in the fog of variability is a major challenge, simply because natural climate variability is large.  And then the problem becomes attributing those changes to a climate mechanism in an interlinked dynamic climate system.

One of those climate detective stories taking some intriguing twists and turns is the rainfall decline in Western Australia which has been the impetus for the Indian Ocean Climate Initiative (IOCI).  Their web site explains:
“In southwest WA, a drying trend has been observed …  The rainfall decline has been most apparent in late autumn and early winter, with a major drop in rainfall totals occurring in the 1970s, and possibly another more recently in the 1990s.  Averaged across southwest WA, a step decrease in total annual rainfall of almost 10% was seen in the mid-1970s, though individual locations would have experienced a greater decrease.”

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Looking for AGW in a Sea of Natural Variability: Drought to Flood (Part 1): A Note from Luke Walker

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After the Queensland floods, Stewart Franks’ research on the interaction of El Nino-Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO) driving cycles of drought and flood in Australia has been advanced as the rebuttal to the proposition by some politicians and scientists that anthropogenic climate change has had a role in recent events. And that the sceptic position forms a more rational and unique unheard insight into the climate system. That indeed it is business as usual, there is nothing to worry about except mopping up, and that the average rainfall of Queensland is (drought + flood) divide by 2.

Franks’ proposition is well based on physical processes and observed data. Of course there have been other supporters of the same position from various fields:

Peter Helman suggests cycles of beach erosion are influenced by IPO cycles, “The impact of sea level rise during the last few decades has not been expressed due to low storm energy (Callaghan and Helman 2008). Climate variability determines when and how sea level change will occur on the coast. Sea level oscillates with decadal and annual climate variability. Over decades, sea level changes are related to oscillation phases of IPO (Figure 3). It has been shown that during phases of negative IPO La Ninã events are more frequent (Verdon 2007), sea level rises at a faster rate than the long term trend (Goring and Bell 2001) and is higher than the long term trend with high storm energy, are periods of coastal erosion (Helman 2007). The longest period of negative IPO recorded was from the late 1850’s to the early 1890’s and the most recent was from the late 1940’s to the late 1970’s. Both of these periods resulted in major changes and erosion of the coastline (Helman 2007).

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Flood Crisis Consistent with Accentuated Hydrological Cycle: A Note from Luke Walker

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Yesterday David Karoly from Melbourne University’s school of earth sciences told the Sydney Morning Herald that while individual events could not be attributed to climate change, the wild extremes being experienced on the continent were in keeping with scientists’ forecasts of more flooding associated with increased heavy rain events and more droughts as a result of high temperatures and more evaporation.

”On some measures, it’s the strongest La Nina in recorded history … [but] we also have record-high ocean temperatures in northern Australia, which means more moisture evaporating into the air,” he said. ”And that means lots of heavy rain.”

Regular commentator at this blog Luke is of a similar opinion and sent me two charts as supporting information.  Click on the images for a larger, better view.

Luke writes about the charts:

“The first shows the 3pm vapour pressure (VP) averaged over eastern Australian the 3pm vapour – a measure of humidity.   As one can see there is some correlation with eastern Australian rainfall.

“Also shown is Australian tropical sea surface temperatures (SST) averaged for the same period with vapour pressure at 3pm.

“Both SSTs and VP are the highest for the 2010 period – highest since 1970.

“These data are consistent with an enhanced AGW hydrological cycle i.e. much greater atmospheric water content and source of convection.

“I am not saying that AGW caused this La Nina but the data are consistent with AGW adding to the propensity for rainfall as suggested by CSIRO studies and AGW theory.

“Interestingly these January 2011 Brisbane and Fitzroy floods were not caused by tropical cyclones.

“The charts should be of interest to serious sceptics.”

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Relevant CSIRO Report:
Abbs, D.J., McInnes, K.L. and Rafter, T. 2007, The impact of climate change on extreme rainfall and coastal sea levels over South East Queensland, Part 2: A high-resolution modelling study of the effect of climate change on the intensity of extreme rainfall events, CSIRO Marine and Atmospheric Research – A report prepared for the Gold Coast City Council
http://www.hpsc.csiro.au/users/abb029/Seth_Westra/GCCC_Phase2_final.pdf

Comment from David Karoly http://www.smh.com.au/environment/fates-conspire-to-concoct-a-recipe-for-disaster-20110111-19mp7.html

Old Growth Forest as Official Carbon Sink: A Note from Luke Walker

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At the United Nations climate conference in Bali last year delegates agreed to include forest conservation in future discussions on a new global warming treaty.  If adopted, REDD (Reducing Emissions From Deforestation and Degradation) means that the value of carbon in intact forests can be realized in carbon accounting.

 

Environmentalists see REDD as a useful vehicle for encouraging conservation of rainforests in the Congo, the Amazon and Asia.

 

This new resource has been termed “Green carbon” to be distinguished from grey carbon in fossil fuels, blue carbon in the oceans and atmosphere, and brown carbon in industrialized forests. There is of course really no real colour difference and the colour is merely a metaphor. [1]

 

The Green Carbon agenda received more scientific support last week with a major paper in Nature. Entitled ‘Old-growth forests as global carbon sinks’.[2]  The paper reports that in forests between 15 and 800 years of age, net ecosystem productivity (the net carbon balance of the forest including soils) is usually positive and this demonstrates that old-growth forests can continue to accumulate carbon, contrary to the long-standing view that they are carbon neutral.

 

The Kyoto Protocol (Marrakesh Accord) definition of a forest makes no distinction between a natural forest and a plantation.

 

Under the Kyoto Protocol definition, a “forest” is:  A minimum area of land of 0.05 hectares with tree crown cover (or equivalent stocking level) of more than 10 per cent with trees with the potential to reach a minimum height of 2 metres at maturity in situ.  It includes (i) young stands of natural regeneration; (ii) all plantations which have yet to reach a crown density of 10-30 per cent or tree height of 2-5 metres; (iii) areas normally forming part of the forest area which are temporarily unstocked as a result of human intervention such as harvesting or natural causes but which are expected to revert to forest.

 

International negotiations on REDD are still continuing and were high on the agenda at the Accra climate change meeting .  However, is REDD all green? What will happen at Copenhagen in 2009?  A number of international environmental groups raised alarm bells at the Accra meeting, claiming that allowing developed countries to purchase REDD credits would absolve them of responsibility for reducing industrial emissions at home.  Some groups proposed setting firm targets for industrial emissions reductions, which could not be substituted by REDD credits.  Others feared that a REDD mechanism would exclude and threaten indigenous communities and serve as an excuse for land grabbing, or endanger sovereignty in rainforest nations.

 

And, for Australian pastoralists, a key question is whether savanna woodland thickening be considered in the discussions, and if so – is it REDD or rangeland degradation? 

 

Luke Walker

Brisbane, Australia

 

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[1] Alan Ashbarry has critiqued the concept of Green Carbon in a piece published at this blog on August 11, 2008, entitled: A Critical Review of ‘Green Carbon: The Role of Natural Forests in Carbon Storage’  

 

[2] Old-growth Forests as Global Carbon Sinks,  by  Sebastiaan Luyssaert, E. -Detlef Schulze, Annett Börner, Alexander Knohl, Dominik Hessenmöller, Beverly E. Law, Philippe Ciais & John Grace, Nature 455, 213-215 (11 September 2008)

 

 

Ferals go Crazy on Australian Sub-Antarctic Island: Who Cares? A Note from Luke Walker

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Rabbits and rats are posing a severe threat to World Heritage values on Macquarie Island, as research reveals widespread damage to terrestrial ecosystems. This includes destruction of vegetation (habitat for threatened albatross species and other seabirds), and catastrophic erosion.

Macquarie Island Under Threat

Erosion and heavy spring rains have caused a large landslip on Macquarie Island, in the Southern Ocean about 1500 kilometres south-east of Tasmania, killing penguins in an important colony.

Rabbits blamed for penguin deaths in landslide

The finer details of introducing dogs to rid a sub Antarctic island of rodents are still be worked through.

Macquarie Island dog plan still in the works

Turnbull to the rescue:

MEDIA RELEASE
The Hon Malcolm Turnbull MP
Minister for the Environment and Water Resources

T76 /07

4 June 2007

AGREEMENT TO ERADICATE RABBITS ON MACQUARIE ISLAND
The Australian and Tasmanian Governments have today reached an agreement to jointly fund the eradication of rodent pests on Macquarie Island to protect its World Heritage values.

The seabird populations and vegetation of the Island are under serious threat from plagues of rabbits, rats and mice.
Following from discussions between our Governments, I am please to announce that we have agreed in principle to provide funding of $24.6 million in equal shares to implement the Plan for the Eradication of Rabbits and Rodents on Subantarctic Macquarie Island.

The Prime Minister has today written to the Premier Lennon confirming the agreement under which the Australian and Tasmanian Governments will provide $12.3 million each to implement the eradication plan.

As Macquarie Island is part of Tasmania, the plan will be implemented by the Tasmanian Government, which will also meet any costs in excess of $24.6 million agreed funding.

The Australian Government funding is conditional on the eradication being managed by a joint Government steering committee supported by a scientific advisory committee.

As it takes two years for the for specialised training of dogs to hunt rabbits without impacting on the wildlife, our Governments have agreed that Tasmania will let contracts for this training and commence all other long-lead work immediately.

The Australian Government provided funding for the development of the eradication plan and in addition will continue to provide $1.6 million per year to support Tasmanian rangers who manage the nature reserve.
Macquarie Island was inscribed on the World Heritage List in 1997 on the basis of its outstanding natural universal values:

• as an outstanding example representing major stages of the earth’s evolutionary history, including the record of life, significant on-going geological processes in the development of landforms, or significant geomorphic or physiographic features; and

• containing superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance.
Macquarie Island is situated about 1500 km south-south-east of Tasmania, about half way between Tasmania and Antarctica at around 55 degrees south. The main island is approximately 34 km long and 5.5 km wide at its broadest point.

Media contact: (02) 6277 7640 – Minister’s office.

A Round Up of Climate Related Articles from Luke Walker

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Study finds global warming affecting bird migration

Climate change may not be noticeable to all humans yet, but the behaviour of birds suggests the seasons have already changed.

A researcher at the weather bureau has found that some spring migrating birds are arriving many days earlier than they used to.

Short-term targets key to tackling climate change: report

A new report says a 30 per cent reduction in greenhouse emissions by 2020 is an achievable target for Australia.

Turnbull hints at ratifying new climate change agreement

Federal Environment Minister Malcolm Turnbull has signalled Australia may ratify the next international climate change deal that comes into effect when the Kyoto Protocol expires.

World energy revolution needed for climate: U.S.

UNITED NATIONS (Reuters) – U.S. Secretary of State Condoleezza Rice said on Monday the world needs a revolution on energy that transcends oil, gas and coal to prevent problems from climate change.

“Ultimately, we must develop and bring to market new energy technologies that transcend the current system of fossil fuels, carbon emissions and economic activity. Put simply, the world needs a technological revolution,” Rice told delegates at a special U.N. conference on climate change.