Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Archives for August 2009

Total Solar Irradiance: Recalculated by N. Scafetta

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Lammermoor Beach Aug09 SunsetTHE popular view on global warming is that the sun has had a negligible influence on climate – at least over the last few decades compared to carbon dioxide. But taking into account the entire range of possible total solar irradiance (TSI) satellite composite since 1980, Nicola Scafetta, just published in Journal of Atmospheric and Solar-Terrestrial Physics, concludes that the solar contribution to climate change could range from a slight cooling to a significant warming, as large as 65% of the total observed global warming.

Here’s a short extract suggesting the science is far from settled:

“DETERMING how solar activity has changed on decadal and secular scales is necessary to estimate the solar contribution to climate change. Unfortunately, how solar activity has changed in time is not known with certainty.

“Direct TSI observations started in 1978 with satellite measurements. For the period before 1978 only TSI proxy reconstructions have been proposed. These TSI proxy models significantly differ from each other, in particular about the amplitude of the secular trends. [Read more…] about Total Solar Irradiance: Recalculated by N. Scafetta

Until Next Year… Little Rose Robin

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red robin“ROSE Robins (Petroica rosea) love to winter at our place on the western side of the Darlington Range in the south-east of Queensland. But come spring and they are off like a rocket to the Lamington Plateau or the New England Ranges to nest.”  Jim Inglis

A Windy Future

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wind tom quirk 1THE Australian government didn’t get its carbon trading legislation through the Senate last week and has now decided, at least for the moment, to just push ahead with that part of the legislation relating to renewable energy targets.   

It seems this legislation is likely to be passed sometime this week and according to many pundits the big winner will be wind farms.  

Wind is available now, is relatively cheap, and could snap up all the relevant concessions under the new legislation before emerging technologies like geothermal and solar thermal are ready for rolling out. 

Is this good news? 

According to the following article… wind farms in South East Australia are unlikely to supply any significant power output that system operators can rely upon, rather they will load the distribution system with sudden variations in power that are not predictable and are of a size that is ten times larger than the random variations of user demand.  [Read more…] about A Windy Future

On ‘Saving the World’ (Part 1)

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“Not all environmental causes are sucker-proof. If one wants to fill up the inner void, by making the world a better place to live, then one should do one’s bloody homework first. And that includes becoming scientifically literate. If one is not willing to take that first step, then one should get a life, and forget about saving the world!”   Larry Fields, August 2009

for some context …  https://jennifermarohasy.com.dev.internet-thinking.com.au/blog/2009/08/clean-up-just-stirs-up/

Carbon Credits for Prescribed Burning: A Note from Green Davey

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 THE Tiwi Islands (Bathurst and Melville) are off the north coast of Australia. They are mostly covered with grassy savanna, much like that in parts of southern Africa. In Africa, this savanna is the result of thousands of years of burning by humans.

If burning is interrupted, then woody shrubs thrive, and the savanna turns into thickets. Due to lightning, fires will still occur, but they will be at longer intervals, and much fiercer, potentially lethal to both humans and wildlife, as in Kruger National Park (http://ag.arizona.edu/oals/ALN/aln54/govender.html ).

I have never been to the Tiwis, but I suspect that they are very similar in this respect to Africa, or Madagascar, where Dr Kristian Kull (Isle of Fire 2006) has eloquently described the political ecology of regular burning by humans.

My attention was caught recently by a television news item about the ‘Tiwi Carbon Project’, in which CSIRO is working with the Tiwi islanders to reduce the carbon released by their fires, and so win them large amounts of cash as ‘carbon credits’. I pursued this back in time, and found a few events which may relate. In 2006, the ABC’s Catalyst program carried a story about a similar scheme in the Northern Territory. The then Northern Territory Environment Minister, Marion Scrymgour (a Tiwi woman), seemed to be working with several Aboriginal Elders, and Dr Jeremy Russell-Smith, a scientist at the CRC Tropical Savannas Management, to promote mild traditional burning, early in the season, to avoid fierce fires later on – wonderful.  [Read more…] about Carbon Credits for Prescribed Burning: A Note from Green Davey