NOAA’s annual State of the Climate report has recently been released, showing the climate change is proceeding apace on all fronts. The 300 page report compiled by 450 scientists from 62 countries confirmed there was a “toppling of several symbolic mileposts” in heat, sea level rise and extreme weather in 2015. From The Guardian:
“The impacts of climate change are no longer subtle,” Michael Mann, a leading climatologist at Penn State, told the Guardian. “They are playing out before us, in real time. The 2015 numbers drive that home.”
Glaciers observed in a recent study are losing between half a meter and one meter of ice thickness every year – two to three times more than the corresponding average of the 20th century. Continue reading Climate clippings 152→
It’s happening, he says, through the action of consumers and industry.
“This is a consumer revolution, as much as it is an energy transformation empowering Australian households, communities and businesses,” Shorten said. (It is) putting control back in the hands of the user, shifting the balance away from big power companies.”
These posts are intended to share information and ideas about climate change and hence act as an open thread. This post has emphasised science, observations and impacts. Comments, about science, observations impacts, and future predictions are welcome. I do not, however, want a rehash of whether human activity causes climate change.
So what does this mean for Australia’s climate? It means that an overwhelmingly positive SAM is keeping the westerlies south and contributing to our drier autumn winters and delivering weather typical of the Riverina to southern Victoria according to Cai. Recovery of the ozone layer and reduction in greenhouse gas emission would stabilise this process, rather than continuing to send it south.
Perhaps the most striking characteristic of Pliocene climate reconstructions is that low latitude ocean temperatures were very similar to temperatures today. High latitudes were much warmer than today, the ice sheets smaller, and sea level about 25 m higher (Dowsett et al., 2009 and references therein). Atmospheric CO2 amount in the Pliocene is poorly known, but a typical assumption, based on a variety of imprecise proxies, is 380 ppm (Raymo et al., 1996).
We conclude that Pliocene temperatures probably were no more than 1-2°C warmer on global average than peak Holocene temperature.
But it was considerably warmer at the poles, with consequent loss of ice sheets bulk. The effect is sometimes known as polar amplification. This involves a strong albedo feedback which could produce a doubling of ice loss every 10 years. The cumulative effect is shown in this graph: Continue reading Climate clippings 13→