With Jenny Goldie, Climate Action Monaro
No, not a meteor strike but eventual effects could be similar
As federal government Ministers deliberate on how much they will weaken the Renewable Energy Target (RET), there are ominous warnings that we may have entered a whole new dangerous phase of climate change.
In mid-July, a helicopter pilot flying over the Yamal Peninsula in northern Siberia discovered an 80 metre wide crater. At first thought to be a meteorite crater, scientists soon realised it was created from forces within, not from outside.
It was a methane blowhole. A store of methane gas buried in the permafrost – stable at low temperatures – expanded as the earth around it warmed. Finally, increasing pressure blew the frost cap at the top of the hole, and tonnes of methane were released.
Other smaller blow-holes have since been discovered in Siberia. Methane vents have been found on the Arctic Ocean sea-floor and off the US east coast, though the methane is usually dissolved in the sea before reaching the surface.
Why does this matter? Because methane is a potent greenhouse gas, with a warming potential 20 times that of carbon dioxide. Although it does not last as long in the atmosphere, it is still a major concern.
A lesson from the past
We should be mindful of what happened in the Permian mass extinction 251 million years ago. Carbon dioxide, released from lava flows in Siberia, gradually warmed the planet by five degrees. That in turn released massive amounts of methane hydrates (frozen methane) from the sea-floor, causing another five degrees of warming, wiping out 96 per cent of marine organisms and 70 per cent of those on land.
Climate change can no longer be ignored. The situation is nothing less than urgent. We have to pull out all stops to keep warming within two degrees, though even that may not be enough.
Two degrees is a global average but warming occurs more at the poles than at the equator. Yamal Peninsula, for instance, had two summers in a row with temperatures five degrees above average.
If this continues, more methane will be released causing even more warming. It’s a case of positive feedback though there’s little ‘positive’ about it.
Meanwhile, the European Space Agency reports that the Greenland and Antarctic ice sheets are not only losing 500 cubic kilometres a year, but the rate of loss has doubled in the last five years.
The Antarctic Peninsular and West Antarctic ice sheets, in particular, are rapidly losing volume and contributing to sea-level rise. While there has been a moderate increase in the East Antarctic ice sheet, it does not off-set the loss in the west.
Senator Nick Xenophon is working with the federal government to try and ensure that the Direct Action Plan delivers the promised five per cent reduction in emissions by 2020. It’s better than nothing but not nearly enough. The Climate Change Authority recommended 15 per cent yet some scientists say a 40 per cent reduction is required.
The methane blow holes suggest that strong, radical action is required if we are to preserve life as we know it.
Image credit: news.com.au