Friday, December 24, 2010

A white Christmas in a warming world

The answer to Wednesday's riddle ("what has six arms, can swallow farms and a million makes a man?") was snowflakes.

At the end of last month, I raised the question many people in the UK are asking at the moment: where did the global warming go? It started snowing in November and here in Edinburgh there have been numerous significant falls over the last three weeks, with snow continuously on the ground the whole time. I've lost count of the days that have dropped below -10ºC and only one or two have nudged above freezing. Transport in the UK has been thrown into chaos, with trains cancelled or delayed, roads blocked, airports disrupted. Heathrow airport, the largest in the world, was closed or running at reduced capacity for much of the last week.*
*This affected us personally since my sister, who was here visiting us until yesterday, was very unsure whether she would be home for Christmas with her husband and children. As it turned out, her flight from Edinburgh to Heathrow was cancelled, and the train which she took instead was delayed by three or four hours, but she managed to get home.

So far, it is shaping up to be the coldest UK December on record, running about 5ºC below average. The last three years have all been significantly colder than average. Prior to that, the trend was for warming winters, which was quite consistent with the widespread scientific understanding anthropogenic climate change, which predicts more warming at night, at the poles and during winters (all patterns evident in the temperature record and which rule out solar forcing as the main culprit). Indeed, only a couple of years ago, the MET Office infamously predicted, "Children just aren't going to know what snow is". So what happened?

I suggested back in November that a pattern of WACCy weather (Warm Arctic Cold Continents) might help us understand this phenomenon. Where did the warming go? The UK is five degrees colder than usual, but much of Greenland is up to 15 degrees warmer than the long term average, and large parts of the Arctic Ocean are more than 10 above average. Indeed, recent studies suggest a link between declining Arctic sea ice and patterns of cold air for the continents in northern latitudes. With less sea ice over the Arctic ocean, more heat escapes from the water (which is obviously no colder than 0ºC) to the atmosphere (which is, as one would expect during an Arctic winter, generally well below zero). This creates high pressure cells, which disrupt the usual wind patterns and lead to the much-warmer-than-usual-but-still-freezing Arctic air being pushed further south over the continents. When this freezing air coming down over the UK runs into moist air being brought from the Atlantic, we get significant (by UK standards) dumps of snow, bringing the country to a standstill.

All this has been mentioned numerous times in scientific papers and reports from NOAA and NASA (and again), but has barely rated a mention in most mainstream media (Monbiot is a notable exception).

Is this having one's cake and eating it if both warmer and colder winters are evidence of climate change? No, because climatologists have never claimed that every place would be affected in the same way at the same time. Global warming is (a) global and (b) only one of the effects of climate change. Climate change means climate disruption, increasingly dramatic shifts from the relative climatic stability of the Holocene that has nurtured the birth of agriculture and the rise of human civilisation over the last ten thousand years or so. Is using the term "climate change" in preference to "global warming" a con to save face? Not at all, since the terms mean slightly different things and both have been in use for decades. (Or if you'd prefer, here's a video response.)

It is not yet clear whether this pattern is likely to become the new normal UK winter as Arctic sea ice continues its apparent death spiral, or whether other factors will prove more significant. On that question hang billions of pounds in infrastructure decisions.

And so tomorrow in Edinburgh, there will probably be snow on the ground for Christmas: a white Christmas in a warming world.*
*I realise that, technically, bookmakers and the MET Office define a white Christmas as at least a single snowflake reaching the ground somewhere in the UK, but snow on the ground is good enough for this Aussie.

34 comments:

craigbenno1 said...

Groan... :) bit much to expect an aussie to get snowflake.

I am a bit of a sceptic using the rising temperature in Greenland as an example of global warming caused by humankind interference.

Historically Greenland has had warm weather, hot summers, mild winters...hence its name Greenland. There is even evidence of a Viking settlement in one of its coves. Remnants of buildings, farming etc...

Historians think that they arrived there in a time of a heat wave, and were caught out years later when the big freeze hit once again.

http://www.archaeology.org/online/features/greenland/

Guardian reader said...

Hypermobility (also here: the expectation of being able to get anywhere quickly and easily.

Two interesting articles about a contemporary (and quite novel) assumption.

byron smith said...

Craig - Thanks for your comment. What's difficult for an Aussie might be simple for Brit at the moment (though none of them got it either).

As for Greenland, notice that I wasn't here putting forward an argument or evidence for anthropocentric climate change, which I take to be so well established a scientific theory as to not need any help from me. The evidence is not simply that Greenland has been warm recently, but involves a wide range of independent data sets covering a wide variety of features of various earth systems (not just temperatures, though they are obviously not irrelevant). You can read a decent summary of some of this data here and a summary of the reasons why this pattern has human fingerprints all over it here.

Basically, there is no other explanation of this data left standing at the moment. Everything else has serious holes and simply doesn't account for all the observed features.

While the southern coasts have some land that is indeed green in summer today, I though you might be interested to know that Greenland may well be a corruption of Gruntland "Ground-land" rather than a reference to a colour. Though if a colour reference was intended, again, this was most likely a piece of propaganda used by early Viking colonists to recruit settlers rather than a careful and accurate description of the whole island. See here for more discussion. (BTW, this is pointed out in the article you link to.)

byron smith said...

As you point out, for at least some of the medieval period Greenland's climate was indeed somewhat warmer than for most of the modern temperature record (and climate change may have contributed to the failure of the Viking colony). However, I don't think we could describe this period as having hot summers and mild winters since the ice sheet covering the vast majority of the island is likely between 400,000 to 800,000 years old.

And while medieval Greenland was somewhat warmer than 20thC temperature averages, much of the rest of the world was likely cooler (see the discussion in IPCC AR4 WG1 Ch6).

Finally and perhaps most importantly, the fact that climate has changed before doesn't mean that there are not excellent reasons for thinking that the climate change of the last forty years or so hasn't been primarily anthropogenic. Climatologists have a pretty decent understanding of the various natural cycles and events that have shaped the history of climate and these can be measured today and they are either insufficient to explain the degree and pace of change or actually suggest that we should be cooling slightly. As I mentioned above, the only explanation that currently can account for the observed data is that the lion's share of the present warming is from the well-understood heat-trapping properties of anthropogenic greenhouse gases (especially carbon dioxide).

byron smith said...

But my point in this post wasn't to mount a case for anthropogenic climate change, simply to point out that a period of unusually cold weather is no kind of knock-down argument for dismissing it and indeed may be a counter-intuitive example of it. Global warming is only part of climate change.

Perhaps in years to come, more Brits will tell each other that riddle because they'll keep having more white Christmases in a warming world.

Or perhaps not. Hard to tell at the moment. What is pretty clear is that if we keep messing with the climate, we're going to regret it more and more as the years go by.

Fortunately, it doesn't have to be this way.

craigbenno1 said...

My use of Greenland was more of a incidental report that warming / colding? is not a recent phenomena... and it has been reported that at various times the poles have changed.


I for one am glad they decided to change the term "Global Warming" to "Climate Change" which is something I was arguing for 10 years ago.

I have no doubt that we are guilty of causing some level of change to the climate... erosion, deforestation, extinction etc.

However I do believe that "Carbon" especially man made is wrongly singled out as being the culprit...

Simply put carbon is needed to support life... young plant life uses it to create oxygen and science has well documented that the natural algae levels in the sea is enough to utilise any carbon increase.

However I would like to see heavy metals and toxins targeted... interestingly some science seems to leave out the fact that the recent volcano eruptions in Iceland and Indonesia produced more Carbon in weeks than what man has produced in 40 years.

Perhaps and I do say perhaps... there cold snap in Europe could have something to do with that?

byron smith said...

warming / colding? is not a recent phenomena
Climate change is not a new phenomenon. What is new the degree to which the present patterns can only be explained when anthropogenic factors are included. See here for a good explanation of why this is important.

I for one am glad they decided to change the term "Global Warming" to "Climate Change" which is something I was arguing for 10 years ago.
There has been no decision to change the terms. They do not mean the same thing and have both been in widespread use for decades. See here for a brief video summary of the history of these terms.

I have no doubt that we are guilty of causing some level of change to the climate... erosion, deforestation, extinction etc.
I wonder if you might be confusing some issues. Erosion (and soil degradation more generally) is a very serious ecological problem, but it is not directly caused by or a cause of climate change. Biodiversity loss is one very significant negative outcome of climate change, but is not itself a cause. Deforestation is both cause of and caused by climate change.

However I do believe that "Carbon" especially man made is wrongly singled out as being the culprit... Simply put carbon is needed to support life... young plant life uses it to create oxygen
Carbon dioxide is indeed crucial for life, but like all substances, too much becomes destructive. We need water to live, but too much and we drown (or die from hyper-hydration). See here for more information.

and science has well documented that the natural algae levels in the sea is enough to utilise any carbon increase.
Can you provide links to the studies that suggest this? From what I have read, phytoplankton are in serious decline (see this recent article in Nature that generated a lot of attention).

However I would like to see heavy metals and toxins targeted...
Most industrialised nations have had regulations controlling these substances for some time. Of course, the most important source of mercury (for instance) is the burning of coal, which also has other problems. So switching away from coal-fired power generation has multiple benefits.

interestingly some science seems to leave out the fact that the recent volcano eruptions in Iceland and Indonesia produced more Carbon in weeks than what man has produced in 40 years.
Can you provide links to the relevant data? The USGS points out that while volcanos produce about 200 million tonnes of CO2 annually, human activities contribute about 29 billion tonnes annually (i.e. more than 100 times greater). The eruptions in Iceland earlier this year actually caused a net decrease in carbon dioxide by grounding so many planes.

Perhaps and I do say perhaps... there cold snap in Europe could have something to do with that?
Perhaps. Do you have any studies that substantiate that link? I've linked to a number that argue for the cold snap being likely caused by a shift in prevailing winds linked to declining sea ice. I'm not aware of any alternative explanations in the published scientific literature at the moment, but would be very interested to hear of any.

Craig, I'm curious, what are your main sources of information about climate change?

craigbenno1 said...

Byron;
Read http://climateaudit.org/

I have been sporadically following this blog for a couple of years. He has made a convincing case against significant temperature increase... particularly search for and look at the historical mean temperatures of Australia and the river flows of the Murray River.

Take this site.. http://www.gungahlinweather.com/articles/factsandfigures.htm It says the hottest day on the Earth was recorded in Libya in 1922.. interesting it hasn't raised since then... It's also interesting that last summer we heard a few times that we had the hottest day recorded for 40 years...meaning 40 years before we had hotter..

In regards to heavy metal toxicities its poisoning of the seas through oil spills which are having a more detrimental effect on oxygen levels in the sea... there is much research to say that its nutrient levels that affect phytoplankton levels and not co2..

http://www.atmosphere.mpg.de/enid/1vf.html

There is much evidence to support that the flow on effect of excesses nitrogen and phosphorous from fertiliser and detergents help increase the levels of plankton and not lower it. The dangers are the other chemicals from these products that are more harmful than beneficial.

Also there is controversy about the amount of money that climate change / global warming is attracting and the lack of accountability within their ranks... read here http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/hadley_hacked/

craigbenno1 said...

Here is the Australian record for the hottest 14 day period in Adelaide
http://www.bom.gov.au/announcements/media_releases/sa/20040220.shtml

Note that the hottest day was in 1939.

byron smith said...

Craig - Global warming is the warming of the globe, and so selecting this or that record is always vulnerable to the charge of cherry-picking. For instance, I could note that 2010 has seen 18 nations set high temperature records, but this would be largely irrelevant by itself. It is the global average over long periods of time that is important. And on that count, 2010 is likely to end up either hottest or in a statistical tie as hottest year, at the end of the hottest decade, with each of the last three decades hotter than the previous ones. The warming is not uniform either geographically or temporally, but the decadal trend is very clear. And global warming is but one aspect of climate change, which is a broader phenomenon also embracing shifts in the hydrological cycle and wind patterns as well as changes in temperature patterns.

Beware relying on Climate Audit or similar blogs for your information on climate. The author has co-authored a single peer-reviewed paper, and it is not highly respected in the field.

In regards to heavy metal toxicities its poisoning of the seas through oil spills which are having a more detrimental effect on oxygen levels in the sea... there is much research to say that its nutrient levels that affect phytoplankton levels and not co2..
I did not mean to suggest that carbon dioxide is the primary input into phytoplankton levels, merely that relying on phytoplankton to deal with excessive carbon dioxide might be wishful thinking given the long term decline in phytoplankton. The blooms referenced in the link you provided are not good news at all, but refer to dead zones which result from eutrophication and which in turn kill nearly all marine life within them as the bloom, feeding on the agricultural run-off, sucks most of the oxygen out of the water, suffocating the fish and other marine life. This, however, is not directly linked to climate change, but is a separate issue. The central point was to question your initial comment that science has well documented that the natural algae levels in the sea is enough to utilise any carbon increase.

And if McIntyre is a less than fully reputable source, Andrew Bolt is far worse. See here for a running list of mistakes and misrepresentations (it runs to over four pages of posts). Can I humbly suggest that bloggers without relevant qualifications are not the most credible source for serious scientific information? I am sure that there are people who are seeking to exploit climate change for financial gain. Yet I doubt that the scientists whose work forms the basis for our understanding of climate and human effects on it are in it for the money. Why? See the links here.

From my reading of holy scripture and personal experience, I have a healthy suspicion of human motives and the corrupting influence of money. And it seems to me that the ones with the great financial incentives in this matter are not the scientists, but those (like Steve McIntyre, by the way) who receive significant amounts of funding from major corporations with the most to lose if humanity wakes up to the dangers of burning our planet's fossil fuels.

byron smith said...

PS Speaking of record temperatures, if we want to avoid cherry-picking, then it is important to look at all the records, not just one or two. Here are the results for doing this across the US over the last sixty years. Of course, this analysis would be more interesting if done for the entire globe, but at least this one makes the point about looking at the bigger picture, not just one or two records.

byron smith said...

And here is a good summary of 2010's extreme weather and how unusual it has been.

Gordon Cheng said...

Is this having one's cake and eating it if both warmer and colder winters are evidence of climate change?

Your answer is 'no', but the correct answer is 'yes'.

Sigmund Freud, however, would be proud of you. All possible answers led to the same conclusion: he was correct.

A happy new year to you, hopefully warmer than what you are currently experiencing.

byron smith said...

I've heard that Australia lost the Ashes, but that can't possibly be true since I saw Hussey hit a ton at the WACA and Siddle captured a six-for in Melbourne.

People say our church is growing, but I know more people who have left over the last twelve months than I can count on both hands.

I've also heard that the UK economy is in a recession, but that can't possibly be true because my friend (who happens to be a bankruptcy lawyer) is doing a roaring trade. He's even put on a couple of extra assistants to help him.

How can both fewer jobs and more jobs be evidence for a recession?

byron smith said...

PS Happy New Year to you as well (though I thought you weren't into calendars - maybe that was just Christian calendars?), and hopefully less flooded with exceptionally heavy rainfall after an exceptionally severe drought than what you are currently experiencing.

byron smith said...

NYT reports the same idea.

byron smith said...

Real Climate: Cold winter in a world of warming, showing that this pattern was predicted prior to last year's cold (European) winter. The same research suggests that it is not necessarily going to continue long term.

Gerry said...

This article contains a few things related to some of the points here: http://www.guardian.co.uk/environment/2011/jan/13/uk-media-ignore-climate-change

byron smith said...

Snow in UK a thing of the past? If you've ever heard that claim ridiculed, this video shows that it is a meme based on a single story written without scientific references and was never claimed in the relevant literature. Let's put it to rest.

byron smith said...

Skeptical Science's take on cold winters in a warming world.

byron smith said...

Dark Mountain: don't get so worked up about not going anywhere. A helpful reflection upon the travel chaos caused by the snow.

byron smith said...

The UK may have been 5 degrees below average in December, but parts of Canada were 20 degrees above.

byron smith said...

Stephen Leahy: Arctic defrost dumping snow on US and Europe.

byron smith said...

Stephen Leahy: Record-breaking April in Europe.

byron smith said...

Independent: The science behind the big freeze: Is climate change bringing the Arctic to Europe?

byron smith said...

CP: Yet another study finds a link between warming Arctic and NH cold suirges.

byron smith said...

CP: Fascinating new study on the effect of a melting Arctic on northern hemisphere weather. The basic idea is that as the Arctic warms faster than the rest of the globe, the temperature difference between the Arctic and the equator drops, which results in a slowing down of the jet stream, which in turn results in slower-moving weather patterns, which exacerbates extreme weather by making dry or wet, hot or cold spells all longer and so more intense.

byron smith said...

90 min lecture from cryologist explaining recent changes in the Arctic and their effects on NH weather.

byron smith said...

Grist: Expect a colder winter thanks to Arctic ice melt.

byron smith said...

Guardian: Warm Atlantic linked to wet UK summers.

byron smith said...

Guardian: Frozen spring and declining Arctic sea ice.

byron smith said...

CC: March hot and cold 2012 vs 2013.

An explanation of why March 2012 was so hot in the US and 2013 so cold.

byron smith said...

CC: March hot and cold 2012 vs 2013.

An explanation of why March 2012 was so hot in the US and 2013 so cold.

byron smith said...

Guardian: Jet stream meanderings affecting weather patterns.