David Archer on methane
Climate clippings 58 led with an item on Methane worries. @ 18 I identified David Archer as one who is “very knowledgeable on the matter [and] thinks the process will be chronic rather than catastrophic.”
He is still of the same opinion according to his post at RealClimate. In short he thinks decomposing permafrost and hydrates will not happen fast enough in sufficient quantity to cause a serious problem:
The methane hydrates in the ocean, in cahoots with permafrost peats (which never get enough respect), could be a significant multiplier of the long tail of the CO2, but will probably not be a huge player in climate change in the coming century.
More wild winters to come?
People who lived through freakish cold weather in the US and Europe in recent years are asking whether there is more to come. The New Scientist has an article which concludes that while the jury is still out there may be a link to global warming. The polar jet stream normally sits like a scull cap on top of the globe in a relatively smooth wavy pattern. In recent times the jet stream has weakened, allowing cold air to flow south and warm air to flow north. The weakened jet stream has a tendency to block, producing persistent cooling or warming.
Here’s a graphic representation of a distended jet stream in the winter of 2100-11:
The article outlines some theories about what’s happening which appear to be consistent with a warming planet. We’ll have to wait and see how things work out.
CO2 and Antarctic glaciation
It seems there has been a conundrum about the onset of Antarctic glaciation, 33.7 million years ago.
Previously published records of alkenone-based CO2 from high- and low-latitude ocean localities suggested that CO2 increased during glaciation, in contradiction to theory.
A new study, The Role of Carbon Dioxide During the Onset of Antarctic Glaciation, has re-aligned observations with theory as reported at Skeptical Science.
The bottom line is that on our present trajectory we”ll be in territory by 2100 where substantial deglaciation will be triggered, albeit over many centuries. We have been told by scientists that emissions reduction commitments made so far since Copenhagen imply a temperature rise of 3.5C by 2100. I think this graph puts the broad implications fairly well:
I got the image from David Spratt and Philip Sutton’s book Climate Code Red: the case for emergency action. I understand it hails from Archer (2006) via Rahmstorf.
Hansen on sea level rise
James Hansen doesn’t, I think, go hard on 5 metres as the likely sea level rise by 2100, but he certainly entertains the possibility. Stuart Staniford at Energy Bulletin looks at his basic argument. It’s based on ice sheet melting being exponential rather than linear. Doubling the melt every 10 years produces a pattern like this:
Hansen and Sato point out that we got a metre every 20 years in Meltwater pulse 1A. I would point out that they have a metre by 2080 and then another four metres in the following 20 years.
My bet is somewhere in between. A metre by 2080 and then perhaps another metre by 2100. Curt Stager’s book tells us that the sea level rose at the rate of a metre every 20 years for a hundred years towards the end of the Eemian, but four times that rate from 2080 to 2100 stretches credibility.
Hansen on extreme heat events
“The most dramatic and important change of the climate dice is the appearance of a new category of extreme climate outliers. These extremes were practically absent in the period of climatology, covering much less than 1% of Earth’s surface. Now summertime extremely hot outliers, more than three standard deviations (σ) warmer than climatology, typically cover about 10% of the land area. Thus there is no need to equivocate about the summer heat waves in Texas in 2011 and Moscow in 2010, which exceeded 3σ – it is nearly certain that they would not have occurred in the absence of global warming. If global warming is not slowed from its current pace, by mid-century 3σ events will be the new norm and 5σ events will be common.”
It should be noted that they looked a temperature anomaly only, from a base of the mean from 1950-1980. Their key result is contained in Figure 5:
Interestingly, continental USA has not had the global pattern of 20C warming.
Jones on shifts and extremes
Roger Jones has just done a post on climate shifts and extremes. He looks at very hot days at Laverton in Victoria and finds a step change in 1997. This is an example of his contention that the climate changes in steps or jerks, rather than in smooth linear patterns, a notion put in a poster at the recent AGU Conference and taken up at Rabett Run.
That graph removes the effects of short-term variability due to ENSO, solar cycles and volcanic eruptions. While the result is elegant and may represent the underlying effect of global warming, I think the idea is that we live in the real world and in the real world things are bumpy and jerky.
Our CO2 exports
Roger Jones has also taken a look at the implications for CO2 emissions of our coal and gas industries. Guy Pearse has done the numbers:
I estimate that Australian coal exports will generate around 75Gt CO2 between now and 2050 – perhaps another 5Gt will come from domestic coal use, and 8-10 Gt from LNG if the expansion of coal seam gas proceeds. In rough terms, between now and 2050, Australian fossil fuel could account for about 1/8th of the remaining carbon budget for 2 degrees C.
By way of comparison, Australia’s emissions inventory for 2009 was 554 million tonnes. IPCC AR4 gave the GHG emissions for 2004 as the equivalent of 49Gt of CO2:
EU tax on airlines
The EU is placing a carbon tax on airlines from 1 January. Countries including the US, China and India are all threatening to declare a trade war over the issue.
I agree with the author of the article. It’s amazing is that this will be a contentious issue at all.
Richard Black at the BBC reports that the US airlines have just lost a legal challenge, and the Chinese are refusing to pay. The EU is standing firm. Black reports that Delta have just added a levy to cover it, all of $3 per ticket!