17 August 2007

Australian Edition

Some climate-related impacts and observations from Down Under, the land 'girt by sea'...

    Australia's 2005 emissions totalled 559.1 million tonnes of carbon dioxide equivalent (Mt CO2-e), the government's Greenhouse Office estimates. This accounted for around 1.5 percent of total world emissions.

    Australia is the world's top greenhouse gas emitter per capita because of its reliance on burning coal to generate electricity. Per-capita emissions fell 14.4 percent between 1990 and 2005, from 32.3 to 27.6 tonnes CO2-e, the Greenhouse Office says. But current per-capita totals are still double the industrialised average of just under 13 tonnes.

So while Aust's total emissions aren't large by percentage, we punch well above our weight, being the leading emitters on a per capita basis. We are using well more than our share. This is one area where we could (and should!) show some global leadership. It is shameful that we are not part of the Kyoto Protocol, whatever merits it does or doesn't have. It suggests that we are not serious about tackling these issues; we are part of the problem, not part of the solution.

Australia is already experiencing human-induced climate change impacts. Multi-year deficiencies of rainfall in many regions. The effects of these recent droughts is exacerbated by climate change – warmer temperatures lead to more evaporation and drier conditions. As a result of these droughts, along with population growth, there is not enough water to support most of the major cities. New water sources are needed in 5-10 years.

In the Torres Strait Islands, there is too much water. The islands are sinking, a result of rising seas resulting from global warming. There have been recent floods in Tasmania, as well as in Gippsland (eastern Victoria) and across coastal New South Wales earlier this winter.

There is also evidence to suggest that our land use choices are affecting the climate. This articles seems a bit strange for some reason. It is not clear why they are interviewing the people they are. This has been studied in Australia as well...

The rabbit-proof fence ... acts as a boundary separating native vegetation from farmland.... [A]bove the native vegetation, the sky is rich in rain-producing clouds. But the sky on the farmland side is clear.


Within the last few decades, about 32 million acres of native vegetation have been converted to croplands west of the bunny fence. On the agricultural side of the fence, rainfall has been reduced by 20 percent since the 1970s.

[A scientific aside: Three hypotheses for this behaviour are related in the item. Only the third idea makes any amount of physical sense. The researchers (and/or the reporter!) are failing to consider the differences in surface moisture flux surface from the different vegetation types. I would expect warmer, drier surfaces with deeper boundary layers over the agricultural land (except perhaps after irrigation)]

Are these events related to anthropogenic CO2 enhancement? That there is a CO2 forcing is undeniable. I mean, of course increasing the CO2 concentration is going to have a radiative effect on the planet. Its not a big conceptual leap to associate the increased forcing and the observed changes. How large of a role do land-use changes play? Its has been observed that cities affect their weather. Irrigated fields do the same (but not forever...). There is a two-way interaction between the land surface and the (micro-)climate of a region. It is a mistake to consider the two sources of change mutually exclusive.

This is an issue cutting across science, policy and society; rightfully the subject of ongoing debate. It must be addressed in order to understand, predict and plan for the impacts of human-induced environmental change. Taking steps as a society to minimize our environmental impact --even something as simple as energy conservation -- is a good start. Phasing out incandescent bulbs is a nice gimmick, but it will take more than that to fix our mess. Even if we only emit a small amount of the global total, it's better for us to accept the responsibility and lead by example. No more 'stamping our feet', getting angry with denial and lies about the climate and our culpability.

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