The Arctic has had a warm winter and spring, and the heat is taking a toll on the sea ice…
I find to my great shame that it’s three years since I last wrote much about the continuing and calamitous decline in Arctic sea ice. Back in the day, you could scarcely contain my enthusiasm for prognostications about the disappearance of the summer ice. But with the fantastic resource that is Neven’s Arctic Sea Ice blog covering the minutiae of every season, coverage from the other side of the world seems a little superfluous. On the other hand, the recent news is especially troubling… Continue reading “It’s grim up North (yet again)”
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?
Continue reading “February’s global temperature spike is a wake-up call”
At the end of June, Professor Jim Renwick of Victoria University gave his inaugural lecture. As you might expect of a climate scientist, it concerns what we know about the climate system and where we’re heading. He pulls no punches. Jim has been kind enough to put together a text version of the lecture for Hot Topic: it follows. You can watch the full lecture, with accompanying slides, on the video embedded at the end of the post.
We live in a golden age of earth observation. With a few clicks of a mouse on a web browser, any of us can see the state of the global ocean surface, the current condition of the Greenland ice sheet, how much rain is falling in the tropics today, and on and on. Plus, the International Space Station (ISS), and a series of satellites such as MODIS give us wonderful images of our home planet. The climate science community can tell, with unprecedented coverage and timeliness, just what is going on in the climate system. It is a great time to be a climate researcher, but also a worrying time, in both cases because we can see exactly what is changing.
One thing the ISS pictures emphasise is just how thin the atmosphere is, a thin blue layer between the solid earth and the blackness of space. Not only is this life-supporting envelope very thin, some of the key gases in the atmosphere are there in only trace amounts, so we can change the properties of the atmosphere easily, by targeting the right gases. The discovery of the ozone hole 30 years ago brought this home with a bang. And we’ve found that build-up of carbon dioxide (CO2) in the atmosphere can have a profound effect on the climate system, right down to the bottom of the oceans.
Carbon dioxide is important because it’s a crucial control on the surface temperature of the earth. It is very good at absorbing heat (infrared radiation) welling up from the earth, then re-radiating both up and down, in the process warming the earth’s surface. The effect is very like a blanket put on a bed – what’s under the blanket warms up. More CO2 is like putting another blanket on the bed and less is like taking away a blanket. No CO2 and the earth freezes – temperatures like we had in the South Island in late June would be the norm everywhere, all the time. While there are several other “greenhouse gases”, carbon dioxide is the most important since it stays in the atmosphere so long, hundreds to thousands of years.
Continue reading “A tale of two hemispheres”
In my column at The Daily Blog this week — Dragon breath and the Age Of Consequences — I take a look at the latest news on Arctic methane. It’s not good, as Jason Box demonstrated by not mincing his words about the seriousness of the threat. For an idea of the consequences, I strongly recommend finding half an hour to look at the video above. Max Wilbert interviews some of the top scientists in the field (including East Siberian Shelf methane expert Natalia Shakova), and the result is a good overview of the pace of change up North and the sheer scale of the permafrost carbon threat.
This guest post is by professor Peter Barrett, executive producer, and Suze Keith, marketing advisor for Thin Ice.
Scientists can tell human stories about climate change, and a group of us have been working on just that for the last few years. We’ve produced a film — Thin Ice – the inside story of climate change — which follows a scientist, geologist and camera buff Simon Lamb, who is concerned at the flak his climate science colleagues have been taking.
Simon travels from the Antarctic to the Arctic. He listens to scientists talk about their work, hopes and fears, and discovers how the astonishing range of research really does fit together. By the end there are just two messages – that our ultimate goal should be zero carbon emissions (in line with the latest IPCC report), and that science really does work. As paleoclimatologist Dave Harwood says to young people at the end of the film:
Don’t be scared by this thing. Come and join in our effort. Be the best scientists and engineers you can, and we’ll deal with it.
Continue reading “Thin Ice: what polar science is telling us about climate”