Tag Archives: climatology

Climate clippings 79

Climate clippings_175These 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.

1. SAM and ENSO divorce

Roger Jones at Understanding Climate Risk has a post on global warming breaking the link between SAM and ENSO, with consequences for our weather.

To help, GMT in the graph means ‘global mean temperature’.

wang-cai-fig-3_500

With the global warming signal taken out (top panel), the relationship between ENSO and SAM is strong but with it in, they depart in the late 1960s (lower panel).

There’s also an article in The Age.

From Jones:

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.

In summer it also allows the easterly trades greater access, bringing in more moisture from the tropics and enhancing La Niña summer rainfall. Continue reading Climate clippings 79

Climate clippings 73

In this edition I’ve stuck to scientific articles, and, incidentally have used a couple (items 3 and 4) from stuff I gathered around this time last year when I thought I might be launching a new blog. For reasons we won’t go into it didn’t happen at that time.

1. Arctic ice watch

While we were on sabbatical last year the northern cryosphere had an exciting time. There was a giant storm in the Arctic ocean, Greenland surface melt covered virtually the whole ice sheet and all sorts of records were broken in the Arctic summer sea ice melt. I’m hoping to do an update to catch us up, but follow this link to see a dramatic animation of Arctic sea ice volume loss since 1979. I’ve posted this image to show how far we’ve come:

volume-comparison-1979-2012-v4

You can monitor Arctic sea ice extent on the NSIDC site. This image is a screenshot from the interactive graph on that page showing the way summer sea ice is sagging:

Sea ice extent_cropped_580 Continue reading Climate clippings 73

Climate clippings 53

GLOBAL warming is unusual

A common response to AGW warmists is that climate has always changed and always will. It’s natural and humans have nothing to do with it. Now via Climate Progress we learn from a study by Svante Björck of Lund University that apart from general moves into and out of ice ages the hemispheres do not warm or cool in sync. When one hemisphere changes the other stays the same or moves in the opposite direction. For example he found that during the Little Ice Age in Europe there were no corresponding changes in the southern hemisphere.

Last week I posted this graph to show that we are giving the system a helluva jerk. In fact we need to go back 15 million years to find CO2 levels as high as today. (if you are concerned about Antarctic thawing be very afraid.)

However, the following graph shows that the hemispheres are not perfectly in sync now:

Hemispheric land-ocean temperatures

The northern hemisphere is pulling away. The reason, presumably, it has more land, and at higher latitudes. Continue reading Climate clippings 53

Garnaut bows out

Ross Garnaut

The central task arising out of the findings of climate science,
according to Ross Garnaut, is “breaking the connection between economic growth and greenhouse emissions”.

In bowing out of his role as the Government’s climate advisor, he did take a swipe at the media which he described as irresponsible and “somewhat rabid”.

“Much of the media and public discussion of climate change policy over the past nine months has been about the crudest and most distorted discussion of a major public policy in my experience,” Prof Garnaut said.

“Facts are ignored, the rules of logic violated and it’s rare for people expressing very strong opinions on particular issues to go back and actually read the document on which they are commenting.”

Continue reading Garnaut bows out

Own goal from the climate sceptics?

If you read the post at Deltoid superficially, you might get the impression that ex-weatherman and blogger Anthony Watts had scored a massive own goal. The bottom line is that he probably has, but the story is complicated, with some wriggle room. Continue reading Own goal from the climate sceptics?

Will the severe winters in Europe continue?

Quite possibly, not every year but with increased frequency according to an article in The Independent.

A study completed in 2009 by the Potsdam Institute predicted this pattern:

Their models found that, as the ice cap over the ocean disappeared, this allowed the heat of the relatively warm seawater to escape into the much colder atmosphere above, creating an area of high pressure surrounded by clockwise-moving winds that sweep down from the polar region over Europe and the British Isles.

Clever them, because it happened in the following two years. They reckon that cold, snowy winters will be about three times more frequent in the coming years. Two cold winters doesn’t prove it, but the pattern’s looking good. Continue reading Will the severe winters in Europe continue?