Climate change, science, the media, and public opinion

Notwithstanding this qualification, one conclusion can be drawn from these polls: public opinion is Australia is polarised on the question of action for climate change.

The disadvantage of polarisation is that public and scientific debate in Australia has degenerated to discredit those who oppose climate change as "sceptics. A similar tactic was used in the past to marginalize and to dismiss opponents of development: "Greenies" described those who disapproved development that had potential adverse environmental impacts; "NIMBY-ism" (the acronym for 'Not In My Back Yard') described communities who protested over development proposals in their neighbourhood. This tactic is inconsistent with accepted principles for conflict resolution and consensus decision-making.

The fault for polarisation of public opinion cannot be directed, exclusively, at science. Nor can fault be solely attributable to the news media. Politicians have also had a key role in contributing to this problem.

What issues should science and the news media focus on to shape public and political opinion to enable Australia to 'move forward' to take appropriate action for climate change? The observations of Donald Rumsfeld on 'facts and the varying degrees of scientific uncertainty' provide a good framework for identifying some of the issues needed to promote informed public debate away from polarisation towards consensus.

"Known knowns: Things we know, we know"

The normal passage of infrared radiation is for it to move from the sun through space to the earth's surface and then to be reflected back into space. The "greenhouse effect" was the initial term used to describe global warming. It arises because of a significant atmospheric increase in greenhouse gases, which act as a barrier causing the reflected radiation to return to the earth's surface.

In order of abundance, the three most significant naturally occurring atmospheric greenhouse gases that contribute to the "greenhouse effect" and global warming are water vapour, carbon dioxide and methane.

The concentration of water vapour is not uniform across the earth's surface. It varies, depending on location (greatest above oceans, lowest above deserts), scale (regional/local) and degree of cloud cover. The concentration of carbon dioxide in the atmosphere can be increased by the burning of fossil fuels. Methane is released into the atmosphere by herbivorous animals, classified as ruminants. Microflora breakdown of herbage occurs in one of their four stomach compartments (the "rumen"). There are about 150 domestic and wild species of ruminants including cattle, goats, sheep, alpacas, antelopes, camels, deer, giraffes, llamas and yaks.

The policy action for climate change in Australia is now based on a Carbon Tax-ETS 'combination'. A "Low Carbon Economy" ("LCE") is its goal.

There are a number of elements to a LCE. Over time, there will be a sequential reduction in emissions of carbon dioxide, directed at eventually reaching a zero level of emissions. The end-point is for the carbon economy to be replaced by a clean (renewable) energy economy.

Nations that signed and ratified the Kyoto Protocol would have done so believing global action to combat climate change was necessary. The Kyoto Protocol recognizes that actions for climate change taken by each country will reflect their specific national and regional development priorities, objectives and circumstances.

Under the Kyoto Protocol, there is a two phase plan of action to combat climate change. Nations must meet their emission reduction targets "primarily" through "national measures" which "promote sustainable development". The Treaty also offers nations "additional means" of meeting their targets by way of three market-based mechanisms e.g. an ETS.