Global warming. What effect might it have upon bushfires?

Global warming. What effect might it haveupon bushfires?

 24 October 2007

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Australia — As officialdom in Victoria, supported by thegreen NGO movement, prepares to excuse their lack of action in bushfirepreparedness, damage mitigation and fire hazard reduction , the threat ofGlobal Warming rears its head in relationship to the frequency and effect thatit will have upon bushfires.

There are probably no more than two ways in which this effect might happen.

First, there might be an increase in the number of days when the conditionsfor fire are at their zenith, that is, where there is a strong northerly windwith very low humidity.

Next, there may be an increase in the frequency of dry lightning storms. Itis possible to have more than a hundred lightning strikes in a singlethunderstorm that actually ignites the forest floor.

Therefore, it must be concluded that, in a hot spell – spring, summer orautumn – if the conditions occur over which homo sapiens have no control,it could reasonably be expected that there would be an increase in the number ofbushfires.

But the “number of fires” is not the critical question. Of farmore importance is fire size and intensity. These factors are not greatlyinfluenced by temperature. Rather the crucial factor is fuel and how much of itis available to burn.

Over much of the bushland in Victoria there has been no effort to reduce fuellevels by any means for the past twenty-five years as a result of pressure fromurban green groups, academics and gutless leadership from the government. We cantherefore expect more of the same. Large uncontrollable fires with erosion andhydrophobic forest floors. Forests destroyed, mudslides and damaging floods.Maybe firefighters killed.

At least initially, over the two and a half million hectares that have beenso brutally incinerated in the past five years, the damage will not be of asimilar dimension because the regrowth has not had the opportunity to die offand litter the forest floor.

The conundrum for our Victorian community is, do we reinstate the fuelreduction measures that worked so successfully from 1944 to 1983 or do we try anew approach? Instead of the fuel reduction burning that causes so much distressto those with bronchial troubles or to those pop-ecologists who do notunderstand the role of fire in Australian eucalypt forests, would it be possibleto use mechanical means of keeping the forest floor clear of the detritus thatso easily ignites?

Some experts refer to  the European model of forest management wheremechanical methods and collection of fuel by peasants keep the forest floorclear of leaf litter, and the resulting material is transformed into bio fuel.Would such a method work in our dense, remote eucalypt forests? On our steepslopes? And what other damage would be done by machines in the fuel collection?In my opinion the European model is completely inappropriate for Australia.

As well as fuel we must consider the need for thinning if the climate isgoing to get warmer and drier. Given the neglect of twenty-five years wheretrees, now at least twenty-five years old, are growing within a fewcentimetres of each other, many of them will have to be removed so those thatare left have a chance to grow. Many areas of East Gippsland Shire show theresult of a lack of forest management. Along the Princes Highway between LakesEntrance and Genoa there are millions of trees growing too close together.There is a pressing need here for a machine to enter the forest, thin out thedense regrowth trees and recycle the resulting timber to enable a better forestto grow.

Alfred Howitt, a leading Victorian explorer, in his 1890 address to The RoyalSociety of Victoria entitled “The Eucalypts of Victoria. Influence ofsettlement on the eucalypt forests” wrote about the open grassy plainsthat were the status quo in Gippsland until settlement.

Of the Snowy River he wrote: “The Valley of the Snowy River, whenthe early settlers came down from Maneroo [Monaro] to occupy it  …. Wasvery open and free from forests.  … clothed with grass, and with but afew large scattered trees of E. hemiphloia.  … The immediate valley was aseries of grassy alluvial flats …”

He continued:  “Within the past twenty five years many parts ofthe Tambo Valley … have likewise become overgrown by a young forest ….Similar observations may be made in the Omeo district”.

Howitt makes reference to unforseen consequences of removing fire fromGippsland when he observed that while young seedlings now had a chance of life,”a severe check was removed from insect pests”. He describes howinsect pests have destroyed many River Red Gum forests in central Gippsland.

Bringing the issue into this century, Mr Vic Jurskis of Forests NSW, observedin “Thedecline of eucalypt forests as a consequence of unnatural fire regimes“that his research suggests that the lack of fire in NSW forests has contributedto the decline in that State’s eucalypt forest. Further, he accepts that,where fuel reduction burning has been removed, it is better to have cattlegrazing.

There can be little doubt that, unless Victorian forests are subjected toeffective programs of fuel reduction burning and thinning, Global Warmingwill have a negative effect. However, in every cloud, there may be a silverlining.

Currently cool temperature fuel reduction burning efforts in Victoria havebeen negligible, but what activity there has been is mainly in autumn.

If Global Warming occurs it will make all of our seasons warmer, providingopportunities to carry out fuel reduction burning in winter as well as springand autumn.

A further benefit to rural Victoria would be a greater number of peopleemployed.

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