David’s meltdown

phill Parsons

Senator Brown when in the Australian parliament flagged a 6m rise some year ago was laughed at, now it is considered a real possibility.

Minister Llewellyn has released a part of Tasmania’s new climate strategy, a report on sea level change by a geophysicist, Chris Sharples, and it includes how that will affect local planning schemes.

One wonders what model of sea level rise he used to conclude that human endeavour on Tasmania’s coast will only be impacted by an 88cm rise.

The volume of ice on the planet, were it all to melt, could give a 70m rise.

Senator Brown when in the Australian parliament flagged a 6m rise some year ago was laughed at, now it is considered a real possibility.

The changes in the rate of melt of the Greenland Ice Shelf have raised questions among glaciologists about the time that it will take for the whole Ice Shelf to melt with the impact on temperature of the current business as usual path taken by much of the global economy.

The collapse of the Larsen B Ice Shelf in Antarctica has shown the processes of rapid melt that can be triggered by temperature increases generating a turning point for large masses of ice.

The West Antarctic Ice Shelf is behaving in a similar manner to the Greenland Ice Shelf, with melt water penetrating glaciers and affecting their stability. Even the recently considered stable East Antarctic Ice Shelf has shown increased rates of movement into the sea.

In Greenland it has been shown that in summer large parts of the huge glaciers that cover it centre are being floated toward warmer lower altitudes and thence out to sea as icebergs at an increasing rate. At what point does this become an all year round phenomenon as thaw comes earlier and freezing later extending the summer there by weeks.

Nobody is sure of the outcome, the behaviour of many systems that affect our climate running ahead of the modelled outcomes without anyone knowing what the tipping point for permanent change is.

Each change appears to feed further changes, a positive feedback with negative consequences.

One of drivers of the climate is the ocean circulation, the warm water from the Gulf Stream maintaining European temperatures. This circulation, which is linked to the Indian and Pacific oceans where warming occurs, can be affected by inflows of freshwater from, for example, the melting of the Greenland Ice Shelf and switch off, the warm saline water ceasing to circulate.

Result – Europe cools and the Pacific and Indian Oceans warm bringing the impacts of low temperatures to the farmlands of Europe and droughts to those of Australia.

Points where dangerous climate change commence are debated, with 450ppm of greenhouse gases or 2.dC of global heating postulated by climatologists as one point. Both the polar regions are beyond this point although the average heating for the whole planet is generally agreed to be 0.6dC. [0.3dC in the southern hemisphere]

In tons of carbon this is a change from 600 billion tons at the start of the industrial age to 800 billion now. Greenhouse gases now lie at 425ppm.

We currently add about 4 billion tons per annum [~2ppmv of CO2eq pa] under the current business as usual approach to greenhouse gas emissions. So before 2020 human activity will add sufficient greenhouse gas to equate to the warming value of that 2.0dC heating, although lag times will see that temperature delayed for a few years.

These lags are the global climate system trying to balance out the temperature forcing of the additional gases by cooling oceans with melt water from the poles. One simple measure to address much warming would be to clean the air of soot. Yes a global air pollution reduction assisted in Tasmania by controlling forest fires and industrial air pollution.

The usual cannot afford it argument

Prime Minister Howard has argued that we cannot afford to address climate change, it will impact on the growth of the economy.

Lately he has talked about the need for nuclear power to delay the rise in greenhouse gases and by implication a nuclear power station for Australia. The head of his own debate has now put the mockers on such an idea without a carbon tax.

The plant and the associated activities are too expensive without a carbon tax and Howard currently opposes such a tax, citing impact on the economy.

Veteran climate scientist Stephen Schneider of Stanford University estimated in 2002 that it would cost $US8 trillion for the stabilization of greenhouse gases by 2100.

The same economists who predict it is too costly for action to prevent catastrophe also claim the world will be 5 times richer in 2100.

Schneider estimated were the $US8 billion to be spent over the next century that level of wealth would be delayed by 2 years [2102] using those same economists figures.

Howard also claims that action taken by Australia will be overwhelmed by growth of the Indian and Chinese economies. [Provided of course such regularities as the Monsoon continue to water Indian agriculture and the glacial ice stored in the Himalayas continues to feed the 5 great rivers of Asia rather than melting away leaving whatever rainfall occurs to drive these rivers into massive floods followed by periods of low flows.]

And so the Minister could, on behalf of the Lennon government, argue the same for Tasmania.

Some may remember back to the time Tasmania acted on scientific advice and banned ozone depleting substances, the idea of no ozone layer actually making it into the hard heads of government as the relaized the outcome for a bath of solar radiation.

Some may even remember the surprise in the scientific community when this phenomenon appeared.

Luckily we chose chlorine as the gas to make chlorinated flurocarbons [CFC’s]. Had chance led to bromine, a suitable alternative, complete collapse of the ozone layer and exposure of life to the suns radiation would have resulted in the human activity driving climate change processes ceasing through collapse of the life support systems upon which we depend.

Bromine, unlike chlorine, would have a much, much longer active life degrading the ozone blanket that govern radiation reaching the earth’s surface.

Without major action by the whole global community the climate will loose its predictability, sea level rise will exceed Sharples conservative short term figure and fires will run through our dry forests as they move to woodland.

The costs to the economy of these impacts will exceed the cost of avoiding such impacts through strategic investment action now.

Tasmania might wish to leave the costs to others as it searches for ways to fund a new hospital for Hobart or Hawthorn to entertain in Launceston or indeed seeks to turn its long term carbon stores [forests] into short term carbon stores [paper], without a sufficient return to the owners, the public.

I have written before about alternatives that Tasmania could adopt at little or no cost, for example solar water heating, biofuels to replace fuel imports or higher housing design standards.

Government could move to biofuels for its buses, to hybrid vehicles for the staff, to recycled paper, even to low energy light globes, as steps on the way to making the economy sustainable and thus the continuation of human activity.

What they cannot afford is a regime of more frequent forest fires through the eastern half caused by a greater summer drying, a collapse in the midlands grazing areas [both resulting from rainfall declines], the loss of coast and its associated infrastructure as sea level rises and rises and rises, of the relocation of plant species as their temperature and rainfall requirements move away from their present range, of new animal diseases and species extinctions as habitats stress, increased public health costs from heat and diseases not usually present and the hydro system floundering at low dam levels thus moving the value from sales interstate.

The Tasmanian Greenhouse Strategy has to include actions that will result in a reduction of the output of greenhouse gases by Tasmanians and those reductions have to be ongoing until we have reduced output by between half and ¾ of the current.

It is no longer conscionable to avoid such action with the impacts predicted by the leading edge science by the continuation of policies that, through their inadequacy, deny the potential outcomes.

Minot tipping points have been passed. For us it is the frequency of EL Nino events. Changing from the typical 6 year cycle that has reigned for through the Holocene [ the modern age following the end of the last ice age] to a 3.5 year cycle, we have entered the Antropcene, where human activity is influencing climate.

phill Parsons rarely recommends a return to the past, the usual home of conservatives, but with greenhouse gases this is his most strenuous recommendation. Otherwise be very afraid for today’s children and for tougher and tougher times today’s cohorts of adults.