Prescribed burning is actually claimed to be a net positive for greenhouse
emissions because small, low-intensity burns produce less emissions than
hot, landscape-scale bushfires, and because they stimulate new growth that
ties up carbon.
Done right, this is probably a valid argument but that requires one to trust
the Departments to do the burns right.
Re the Bushfires Royal Commission recommendation for an annual burn target:
this is still a live issue in Victoria. The target is a flat 5% of all
public land every year (and wildfires do not get counted.) A burn every 20
years would drive malleefowl (for 1) to extinction if there is no
long-unburned mallee to breed in.
On the other hand, the annual target of nearly 400,000 hectares is still
less than the Big Desert-Murray-Sunset complex fire in 2002, that nearly
wiped out Mallee emu-wrens in South Australia. A 400,000 hectare burn in the
wrong part of Murray Sunset and Hattah could wipe out the Victorian
population and drive the whole species to extinction in a weekend.
There is a need for some prescribed burning, for ecological reasons as well
as for public safety. They create a mosaic of vegetation classes that
different species need - e.g. malleefowl feed on wattle seeds etc. in
disturbed habitat, and the Triodia that Mallee emu-wrens live in senesces in
long unburned habitat. And the firebreaks can protect some long-unburned
"lifeboat" patches from landscape scale bushfires.
I think we need to argue the conservationists' case and keep the bastards
honest - not blindly trust any government department, but not fight to
despair over every hectare "lost". What we should demand is that decisions
are backed up by science and data, not driven by political and financial
imperatives, which is what worries us most about the Victorian approach.
Ross Macfarlane
-----Original Message-----
From: Jeremy O'Wheel
Sent: Thursday, September 05, 2013 3:17 PM
To: Philip Veerman
Cc: Roger Giller ; Birding-aus
Subject: the fire hazard reduction program
The amount of extra heat from the sun "trapped" by the CO2 from burning
fossil fuels is far more significant than the amount of heat generated from
combusting those fossil fuels because the CO2 has an atmospheric half life
of is significantly longer compared with a dissipating unit of heat. The
heat that we receive from the sun is much greater, and the fossil fuels
help "trap" that heat for many years. I believe the estimates are 0.018
watts/square meter for heat generated by burning fossil fuels, while 2.1
watts/square meter for CO2.
Jeremy
On 5 September 2013 14:33, Philip Veerman <> wrote:
I have also thought that but I do not understand why more attention is not
devoted to that what is happening is that the solar energy that was
absorbed
into the system for many millions of years and stored as what is now
fossil
fuels, has been largely used and that energy released within about 200
years, ultimately as heat. Thus it is not just the burning of fossil
fuels
but the unbalance due to millions of years of accumulated solar energy
being
released almost instantaneously. Why is that not talked about as a factor
that impacts on warming?
Philip
-----Original Message-----From:
On Behalf Of Roger Giller
Sent: Thursday, 5 September 2013 1:58 PM To: 'Frank O'Connor';
Subject: Re: [Birding-Aus] the fire
hazzard
reduction program
Frank,
While agree with your other points I can not let the first one go
unchallenged.
Burning the bush is only one step in a relatively short term cycle. As it
grows it sucks up carbon. When it is burnt, or dies and decays, the carbon
goes back into the atmosphere it came from. If the bush is burnt every X
number of years then on average nothing changes. (Note that I am only
referring here to the effect on atmospheric carbon dioxide levels, not the
ecology, which sadly is the loser in all this) The problem with climate
change is the burning of fossil fuels. They locked up the carbon millions
of
years ago. Life as we now know it has evolved to be happy with the
concentration of carbon dioxide that remained in the atmosphere, until we
started adding to it by accessing and burning the fossil fuels.
Roger Giller.
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