February’s global temperature spike is a wake-up call

This is the largest warm anomaly of any month since records began in 1880.

This article, by Steve Sherwood, of UNSW Australia and Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research, currently working in Australia, first appeared at The Conversation.

Global temperatures for February showed a disturbing and unprecedented upward spike. It was 1.35℃ warmer than the average February during the usual baseline period of 1951-1980, according to NASA data.

This is the largest warm anomaly of any month since records began in 1880. It far exceeds the records set in 2014 and again in 2015 (the first year when the 1℃ mark was breached).

In the same month, Arctic sea ice cover reached its lowest February value ever recorded. And last year carbon dioxide concentration in our atmosphere increased by more than 3 parts per million, another record.

What is going on? Are we facing a climate emergency?
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Fall in San Francisco: Jim Renwick’s AGU report

Jim RenwickI took part in the 2015 AGU Fall Meeting, held at the vast Moscone Center in San Francisco, 14-18 December. As always, it was an absolute cornucopia of everything to do with the Geo/Earth Sciences, from exoplanets to the earth’s core to climate change and science policy, delivered by over 20,000 geoscientists. The Fall Meeting is always a blast, a real mind-expander.

This year, I was committed to chairing sessions first thing on Monday morning and then again on Friday. Monday’s session was “Evaluating Reanalysis: What Can We Learn about Past Weather and Climate?” with my sub-session having a focus on polar regions. The Thu/Fri session was “Precipitation over Mountainous Terrain: Observations, Understanding, Modeling, and Future Prospects”. In between, I soaked up as much as I could, wandering the halls to hear and see fascinating presentations on climate history, science communication, sea ice, and designing climate change musicals for primary school children. Here’s a few highlights, my personal “tip of the iceberg” from this year’s meeting.
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Antarctic sea ice: The end of the trend?

west antarctic sea iceUnusual things are happening to Antarctic sea ice extent. We are about a month away from the traditional time of maximum extent (around 20 September), and each year for the last six years, total sea ice extent around the Antarctic has been above normal. The last three years have been record-breaking, with 2014 seeing the 20 million square kilometre threshold exceeded for the first time since satellite records began in 1979 (Figure 1). But this year, sea ice growth stalled in early August and is currently going nowhere. For the first winter since 2008, total Antarctic sea ice extent is below normal (Figure 2).

ASIExtentanom201409 Figure 1: September Antarctic sea ice extent, percent difference from the 1981-2010 normal.

Antarcticseaice20150819 Figure 2: Antarctic sea ice extent in 2015 (blue line). The dashed line shows 2014 extent, the gray line the 1981-2010 average extent and the shading represents the two standard deviation spread about the average.

What’s more, the pattern of sea ice change this winter is the opposite of the trend pattern we’ve seen over the past few decades towards more ice around the Ross Sea and less ice near the Antarctic Peninsula1. This year, near the Antarctic Peninsula, we have more ice than normal, and less than normal north of the Ross Sea and across parts of the Indian Ocean (Figure 3). A real turn-around.

ASI20150816extentmap Figure3: Antarctic sea ice coverage for 16 August 2015 (white). The thin solid line shows the 1981-2010 average sea ice edge for this date.

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  1. Turner, J., J. C. Comiso, G. J. Marshall, T. A. Lachlan-Cope, T. Bracegirdle, T. Maksym, M. P. Meredith, Z. Wang, and A. Orr, 2009: Non-annular atmospheric circulation change induced by stratospheric ozone depletion and its role in the recent increase of Antarctic sea ice extent. Geophys. Res. Lett., 36, L08502, doi:08510.01029/02009GL037524. []

Something for the weekend: boy child birth on the way, will get feet wet

Odds are shortening on the imminent arrival of an El Niño, as Peter Sinclair explores in his latest video for the Yale Climate & Media Forum (see also Climate Progress), and we can expect a wild ride. Meanwhile the ice continues to melt and the oceans rise: in Wellington and Christchurch they’re planning for 1 metre by the end of the century. As Jim Salinger noted this week, we need a big picture fix for the problem — adaptation is essential, with mitigation to prevent the worst happening. And while China plans a high speed train network to span Eurasia and North America, oil investors are looking nervously at the $1.1 trillion oil companies are gambling on a high carbon future. Yes folks, it’s time for another open thread, and there is no shortage of hot topics to discuss…

Herald gives de Freitas platform to smear climate science

Climate change denier and Auckland University geographer Chris de Freitas seems to have fast access to the dialogue pages of the NZ Herald. His latest effort this week is a long ramble ostensibly around the possibility of an El Niño this year, but at its centre contains a nasty slur on the honesty of climate scientists. He confuses, presumably deliberately, predictions of a weather event in the short term with the longer term predictions of climate change.

The short term prediction relates to the possibility of an El Niño event this year. He claims NIWA’s reported 50% chance of an El Niño is not a prediction at all, but more akin to tossing a coin. This observation doesn’t stand up. NIWA doesn’t say every year that there’s a 50% chance of an El Niño. They were drawing attention to current developments which point in the direction of an El Niño.

Nevertheless de Freitas presumably sees his observation as a useful build-up to his planned attack. His next step is to comment on how incredibly complex climate systems are, and to quote no less an authority than Albert Einstein who said of the weather that prediction for even a few days ahead is impossible. Incidentally I’ve never seen a climate scientist claiming to predict the weather next week. But in de Freitas’ mind this leads to a climax:

The problem is complicated by the fact that the public usually fear the worst, and fear sells. So, if the period for which the prediction is made is beyond the end of the climate scientist’s lifetime, such as with long-term predictions of human-caused climate change, or “global warming”, any scary prediction will attract attention and hopefully also research funds or job promotion.

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