Fire and rain

by Gareth on August 12, 2010

The last few weeks have seen some extraordinary weather events around the world: relentless extreme heat in Russia, biblical flooding in Pakistan and devastating landslides in China. Tens of millions of people have had their lives disrupted and thousands have died, and — beyond reasonable doubt — global warming is playing a part in creating these extremes. But how much of a part? Michael Tobis asked this question in a recent post:

Are the current events in Russia “because of” “global warming”? To put the question in slightly more formal terms, are we now looking at something that is no longer a “loading the dice” situation but is a “this would, practically certainly, not have happened without human interference” situation?

The answer, at least in the case of the current extremes, would appear to be yes.

Jeff Masters at Weather Underground has (as usual) been providing exemplary coverage of the Russian heat wave, and in a post on August 6th he described it as “one of the most remarkable weather events of my lifetime”. Over the month of July, Moscow’s mean daily temperature was 7.8ºC above normal (the previous record, set in 1938, was 5.3ºC above normal), and since the beginning of August the daily maximum has been consistently 15ºC above average, which Masters describes as “a truly extraordinary anomaly”. At the time of writing, Moscow had experienced 29 successive days with temperatures over 30ºC, easily the longest and most intense heat wave since records began. Masters quotes Alexander Frolov, head of Russia’s weather service:

Our ancestors haven’t observed or registered a heat like that within 1,000 years. This phenomenon is absolutely unique.

What’s particularly striking about this event is the large margin by which previous long-standing records are being smashed. The Economist, in an excellent article on climate change and extreme weather, quotes Dutch meteorologist Geert Jan van Oldenborgh on the odds:

…a straightforward comparison of the temperatures seen this summer with those of the past 60 years suggests that a large patch of Russia is experiencing temperatures which might be expected only once every 400 years or so. Some places within that patch are hotter than might be expected over several millennia.

Those numbers assume the climate isn’t warming. When van Oldenburgh assumes warming:

…the heatwave starts to look less improbable — more like the sort of thing you might expect every century. As the warming trend continues in the future, the chances of such events being repeated more frequently will get higher.

Van Oldenborgh did a similar analysis of the heat and cold anomalies of last northern hemisphere winter, which I covered back in April. The key point is that if the climate were not changing, an event as dramatic as the Russian heatwave would be very, very unlikely. If we factor in the warming trend, it remains unusual, but less so. And if that warming trend continues (and it will), then we can expect more record-breaking heat waves around the world.

Global warming impacts the weather we experience in two ways: by increasing the probability of new records — when a heat wave happens, you are likely to get more warmth (see the graph in my post on rainfall). But there is a second impact: the potential for changes in the circulation of the atmosphere. The climate of any part of the planet depends on lots of factors, but the flow of weather systems is crucial. As an example, consider the South Island of New Zealand. The prevailing (or normal) wind is westerly, and when that wind bumps into the Southern Alps it drops rain, and lots of it. Hence rainforest, speedy glaciers and tourism. On the other side of the Alps, we get warm dry winds and little rain. Now imagine that the frequency of easterly winds increases and westerlies decrease. The east coast gets wetter, and the west coast dryer. Cue big change in climate, even if the temperature doesn’t warm. There’s actually a hint of this happening in the modelling toward the end of the century — though for the east coast of the north island, not down here.

So can we draw a line between Russian heat, flooding in Pakistan and China and changes in the pattern or shape of weather? Perhaps a combination of the after-effects of El Niño, record sea-surface temperatures in the tropical Atlantic and a reduction in Arctic sea ice are affecting the way the jet stream meanders around the northern hemisphere, creating a persistent ridge of high pressure over Russia — a blocking pattern that has flow on effects for Asia. Wired asked Kevin Trenberth if the heat and floods could be linked:

“The two things are connected on a very large scale, through what we call an overturning or monsoonal circulation,” he said. “There is a monsoon where upwards motion is being fed by the very moist air that’s going onshore, and there are exceptionally heavy rains. That drives rising air. That air has to come down somewhere. Some of it comes down over the north.”

Rob Carver at Weather Underground explains more here, New Scientist discusses the “frozen” jet stream here and UK Met Office scientist Peter Stott (who wrote the definitive paper on the record-breaking European heat wave of 2003) offers his thoughts at the Guardian.

What I find scary in all this is the multiple coincidence of record heat and catastrophic flooding in Pakistan and China — in a year where the first six months had already set a record for insurance losses on extreme events. The last 12 months have been the warmest in the global record. A modest El Niño event has boosted temperatures and affected weather patterns in an eery echo of events that followed the great El Niño of 1997-98. Back in 1999, Kevin Trenberth reviewed the extreme weather events of 1997-98. It was, as he suggests, a wild ride:

In early August, for example, major floods devastated parts of Korea, and in August and September 1998, extensive monsoon-related flooding struck heavily-populated eastern India and Bangladesh. Widespread heavy rains in China, at about the same time, released the mighty Yangtze River from its banks, with ensuing reports of more than 3,000 deaths, some 230 million people homeless, and over $30 billion in flood damage. In the summer of 1998 heat waves and air pollution episodes plagued many regions of the world, particularly in Egypt and other Mediterranean countries, and in southern Europe. In New Zealand, record floods in July and October 1998 were the worst in 100 years. But the costliest disaster of them all, in terms of human life, struck the Caribbean in late October. Hurricane Mitch caused the deaths of more than 11,000 people in Honduras, Nicaragua, Guatemala and El Salvador, primarily through the extensive flooding that followed prolonged and heavy rains.

This time round the floods are in Pakistan instead of India and Bangladesh, and the heat has moved north from the Mediterranean to Russia. The Atlantic hurricane season has not yet really got going, but we can only hope there won’t be another Mitch. In the 12 years since that El Niño, the climate system has continued to accumulate energy. When an ENSO event releases that energy it has to go somewhere, and that’s into heatwaves, floods, hurricanes and melting ice.

As the years go by and the warming continues, those extremes are only going to get worse. To me, it looks very much as though it won’t be a gradual warming that causes us the biggest problems, it’ll be the direct and indirect effects of increasing weather extremes. Hot years are going to be hard years for humanity.

[Update: The Wonk Room covers the same subject, but includes an interview with Rob Carver:

I agree with Michael Tobis's take at Only In It For the Gold that something systematic has changed to alter the global circulation and you'll need a coupled atmosphere/ocean global model to understand what's going on. My hunch is that a warming Arctic combined with sea-surface-temperature teleconnections altered the global circulation such that a blocking ridge formed over western Russia leading to the unprecedented drought/heat wave conditions. Without contributions from anthropogenic climate change, I don't think this event would have reached such extremes or even happened at all.

]

[Update 2 (in quick succession): Stu Ostro at The Weather Channel posts on Russian heat, extremes and 500mb anomalies:

The upshot: Whether with temperatures, precipitation, or storms (tropical or otherwise), and regardless of in which direction the extremes are, it's a case of Weather Gone Wiggy, and this is happening at the time when the Earth's climate is at an exceptionally warm level compared to that of at least the past century. There have been extremes for as long as there has been weather; it's their nature which is changing along with changing atmospheric moisture, stability, and circulation patterns.

]

[Update 3 (on a roll!): World Meteorological Organisation on recent extremes]

[Update 4: The Guardian expands on Weather Underground's list of new temperature records.]

[Update 5, 14/8/10: Jeff Masters posts on the jetstream and its influence on the heatwave: The Great Russian Heat Wave of 2010 is one of the most intense, widespread, and long-lasting heat waves in world history.]

[Sweet dreams and flying machines in pieces on the ground]

{ 22 comments… read them below or add one }

John August 12, 2010 at 9:36 pm

Go Russia (a country New Zealand is paying to save the planet) – the new clean green (joke) – I guess thats why we are being taxed so harshly by the Emissions Trading Scheme. Like the religious zealots of old – making our backs bleed will free us of our carbon dioxide and methane (cow farting) sins. Stupid stupid greens

John August 12, 2010 at 11:51 pm

Of course you suppress an alternative view. Of course you are uncomfortable with that alternative view. Of course you justify hiding My comments, justifying this as the the choice of the majority. Not one reply – not one person prepared to engage. Just lemmings heading for the cliff Full of emotive, bordering on the religious ecobabel

TBWood August 13, 2010 at 12:01 am

Hi John, you’ve posted late at night – perhaps those who’d normally comment are asleep?

I don’t think you understand how the rating system works. I was able to read your comment just fine.

Can you post again, and state your point more clearly please?

Thanks

TB.

Mike Marriott August 13, 2010 at 2:12 am

John,

We’re simply pragmatic, realistic and focused on the science.

We’re moving on, thinking about adaptation and mitigation. There’s work to be done. See you when you catch up with the reality.

Watching the Deniers August 13, 2010 at 2:21 am

@ Gareth,

“…After much deliberation, I’ve decided… Bob Dylan’s “A hard rain is gonna fall” ..as the song for our changed planet…

Apart from the obvious connotations of a changed climate to the metaphorical “hard rain” of the song, Dylan’s music strikes me as the epitome of the hardscrabble, no-nonsense approach to life those in a changed world will need.

Listening to the lyrics I can’t help but be struck by some of Dylan’s prescient imagery. He evokes images of dead seas, the echo thunder and a wave that “will drown the world”.

The song is a lament for the earth that once was, and a song for the children who will inherit a changed planet…

And what did you hear, my blue-eyed son?
And what did you hear, my darling young one?
I heard the sound of a thunder, it roared out a warnin’
Heard the roar of a wave that could drown the whole world
Heard one hundred drummers whose hands were a-blazin’
Heard ten thousand whisperin’ and nobody listenin’

http://watchingthedeniers.wordpress.com/2010/05/26/a-hard-rain-is-going-to-fall-soundtrack-for-a-changed-world/

Gareth August 13, 2010 at 10:50 am

Not bad. Though the song was written in 62 and is usually taken to be a response to fears of nuclear war, it obviously works well in an environmental context. Still, I like Fire & Rain (as does MT!).

Macro August 16, 2010 at 10:50 am

I’ve been thinking upon this for some time now – “Where is the minstrel for the cause?” The protest movement of the 60’s had Dylan and Biaz et al, but Bob’s 70 now, and he gave up wanting to be seen as the voice for change years ago, and fair enuf! But Global Warming NEEDS young poets and singers to strike in the hearts and minds of the younger generations the desire to confront politicians and demand change. I haven’t seen anything like this on tv4 yet (and I occasionally watch when my 22 year old is home). Does anyone know?
The coffee clubs of the 60’s were the hotbeds of alternative ideas and “folk” was the music of the time. We need a new cultural revolution from the younger generations, but I do not see any sign of it as yet.

TomG August 13, 2010 at 4:26 am

John, you don’t have an alternative view.
You have your head firmly stuck in the sand and a death grip with both hands on your wallet.
If we are on the path to a Lovelock scenario, all your money and material wealth will be totally worthless.
I personally don’t expect this extreme Lovelock scenario, but in view of what is happening around our globe, who knows?
He might be right.

Byron Smith August 13, 2010 at 5:09 am

Lovelock doesn’t need to be right for CC to be catastrophic. Something can be catastrophic without being apocalyptic.

Steve Bloom August 13, 2010 at 6:21 am

“Sand.” Nice metaphor, TomG! :)

Gareth, don’t forget that the upward and outward expansion of the tropics has pushed the Hadley cells and jets poleward, and that this has been not only measured but formally attributed to anthropgenic warming of the atmosphere. The surprise would be if things like the monsoons failed to change in response.

Gareth August 13, 2010 at 10:53 am

No, I hadn’t forgotten — in fact the increased frequency of easterlies expected in northern NZ is almost certainly linked to that expansion, and the intensification of westerlies further south (already observed) is at least partly a function of the wind bands being “squeezed” as the tropics expand.

Steve Bloom August 13, 2010 at 5:04 pm

I’ve been thinking of a list of things that should have sent us into a panic over climate, and the observed expansion of the tropics is high on it. Chronologically, probably the first item on the list is Wally Broecker’s 1975 paper, and the second is Jim Hansen’s detection of a signal. Lately they seem to have been coming a lot thicker and faster.

Eli Rabett August 13, 2010 at 12:51 pm

Before we worried if climate change was loading the dice, now we have to start thinking about whether climate change is loading the gun

Gareth August 13, 2010 at 1:10 pm

D’ya feel lucky, punk? Well, do ya?

watching the deniers August 13, 2010 at 2:14 pm

@ Eli.

Quote of the year mate. And, sadly spot on.

Steve Bloom August 13, 2010 at 5:07 pm

We could re-word this to be a bit more ominous, e.g.:

We thought Mother Nature was just loading the dice, but it turns out she was loading her gun.

bill August 13, 2010 at 6:01 pm

Passes the ‘can I imagine this being intoned in a resonant American accent over the soundtrack of an action movie preview’ test! We’d be able to cull together some pretty graphic and scary footage, too…

AGW: the movie – it might not be the Apocalypse, but it won’t be pretty…

lprent August 13, 2010 at 6:36 pm

Great post, and so is Bryans. I’ll link to them as further reading to the one I put up today on the same topic

Byron Smith August 13, 2010 at 7:28 pm

We thought Mother Nature was just loading the dice, but it turns out she was loading her gun.
Or perhaps: we thought we were just loading the dice for a game of craps, but it turns out we were loading the gun for some Russian roulette.

CTG August 13, 2010 at 11:12 pm

Well, I’ve said this before, but it’s worth repeating.

James Burke’s 1990 documentary After the Warming predicted exactly these sort of extreme weather events. The only thing he got wrong was the date – he thought it would be the 2020’s before we started seeing things this bad.

Hands up who still wants to scrap the ETS?

Steve Bloom August 14, 2010 at 4:53 am

You underestimate the power of short-term thinking, CTG.

bill August 14, 2010 at 9:45 pm

I suspect over the next few decades we’re going to get a unique empirical evaluation of the truth – or otherwise – of the following statement –

‘Ordinary people [or, at least, relatively affluent, educated Westerners] would behave differently and act swiftly to do the right thing if only they weren’t being systematically disinformed by the media and systematically misrepresented by their political leaders, even if doing so impinges significantly on their own lifestyles’

Now, are you feeling lucky, dear reader?

{ 4 trackbacks }

Previous post:

Next post: