When Douglas Adams finally left the building, he left behind the Hitchhiker series, the Long Dark Tea-Time of The Soul, and Last Chance To See – an inspiring book about his travels to the ends of the earth to try and catch an actual glimpse of some of our most significant endangered species. A task that is getting harder for human eyes supposedly, because the amount of light in the world is decreasing.
Global Dimming
Throw ‘Global dimming’ in your google, and you’ll get a rash of science pages that outline a gradual reduction in the amount of sunlight observed reaching the Earth’s surface since the 1950s. Apparently we had 5% less light in the 1990s, than in the 1950s. The good news is that this trend has supposedly reversed during the last decade. The bad news is that Global dimming creates a cooling effect that may have led scientists to underestimate the effect of greenhouse gases on global warming.
Global dimming is mainly attributed to pollution – such as aerosols – and the way that increased particles in the air reflect sunlight back into space. Apparently this is especially notable with clouds, where the combination of water droplets and other particles greatly increases the reflective density of the cloud. Post 9-11, when air travel was briefly suspended in the United States, the reduced amount of vapour trails in the sky were linked in a study to an increased amount of daylight hitting the planet. It’s worth noting that the amount of sunlight hitting the atmosphere hasn’t changed, only the amount which actually makes it down onto the surface of the planet.
Warming Vs Dimming?
Many scientists believe we have been protected from more extreme effects of global warming because of global dimming, and that resolving global dimming may therefore have a major and previously unpredicted impact on temperatures and sea levels. This is also amidst a general shift in climate change circles, to a position where scientists are thinking our estimates of temperature changes in the next century are much lower than they should be.
The Last Eyelids Ever
Of course, no Tasmanian tiger has had to deal with reduced rates of sunlight reaching the planet surface, the last tiger dying in captivity in a Hobart zoo on a winter in 1936. Animals were meant to be put inside shelters on the cold Hobart nights, and some zoo apprentice forgot to put the tiger in one winter night, and so the last eyeblinks for that entire species happened sometime before dawn.
Of course, the iconic stripes of the tiger have meant it now lives on a potent symbol of Tasmania’s fine beers and other assorted agricultural products. The lesser blessed Paradise Parrot, Kangaroo Island Emu, Broad-faced Potoroo, Eastern Hare-wallaby who do not sure the same visual status, arguably have sunk into an even deeper extinction.
Reviving The Eye of The Tiger?
Aside from occasional claimed sightings of (yeti and ) tassie tigers by tourists, the thylacine would seem to have disappeared. The Australian Museum in Sydney famously began a project in 1999, attempting to resuscitate the species – having discovered that a particular tasmanian tiger foetus had been discovered preserved in such a way that DNA sampling seemed possible. By 2002 the y declared some success, having extracted usable DNA from the specimen. In Feb 2005 however, they closed the project after tests showed the specimens’ DNA had been too badly degraded by the (ethanol) preservative. By May 2005 the project was back on however – being restarted by a group of interested universities and a research institute. Hopefully there’ll still be some Tasmanian habitat left for the revived beasties, by the time the scientists are up to version 2.0.
jean poole