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CLIMATE WARS

It has become akin in some ways to the evolution vs. creation debate.

On the one hand is established science. On the other, there is a diverse body of opinion and belief with a diverse range of "alternative" explanations, the only thing held in common being the assertion that the 27 billion tonnes of carbon dioxide that we add to the atmosphere every year from burning fossil fuels is harmless.

Why the whole 30+ years climate debate has gone up a gear lately is an interesting subject that no doubt history will still be chewing over in another 30 years. A few years ago on here I was lambasting the media for attempting to blame everything in the Natural Disasters Department on global warming - which at the time was certainly a frequent observation in the press.

More recently, like a pendulum, much of the media has swung in the opposite direction and the papers are attempting to tear the science apart - and since that's a bit technical, attempting to tear apart the scientists and their institutions instead. The debate has become unpleasant, spite-ridden, focussing on attempts at character-assassination, misquotation and manipulation of the words of others as the soundbites bounce around the echo-chamber from one outlet to another.

The clear observation from where I am sitting is that the science itself remains unchanged, despite the numbers of things with "gate" on the end that are being cooked up on a weekly basis, most of which have been soundly debunked. And what of the genuine errors uncovered? A good number of Himalayan glaciers ARE retreating despite the silly date that got into page 493 of the WG2 section of the IPCC's 2007 report. What do people expect? An error is found in a report and the glaciers all immediately start to advance again? To turn the 2035 flaw into a statement like "The glaciers in the Himalayas are NOT retreating" is to make an even more fundamental error. One might think that people would grasp that the laws of physics do not respond to public opinion. So what's going on?

The blatantly obvious political battles are easy to identify - for example, the run-up to COP 15 - the Copenhagen conference - would guarantee a lot of noise from those organisations rigidly opposed to any deviation from Business As Usual. I do not think the release of the carefully-prepared archive of CRU emails was a coincidence of timing. It was a political act, with sabotage being a not-unreasonable guess as to its intended goal. One has to ask, however, this rather pertinent question: if the science behind the fact that carbon dioxide is a forcing agent that causes warming (first published: 1896, with thousands of supporting papers since) is so flawed, why was all this skullduggery necessary?

Meanwhile, a cold UK winter reminiscent of some of those of the late 1970s and 80s is guaranteed to bring newspaper headlines such as "SO THIS IS GLOBAL WARMING??!!?" - this happened in the 2008-9 winter too, another one in which there was some very cold weather. Likewise, the eastern USA saw "Snowpocalypse" and "Snowmageddon" this past few months. On a thousand Internet Forums right now there are apoplectic people, sparks flying from their keyboards: "THEY SAID THE ICECAPS WOULD MELT. THEY HAVEN'T. THEY SAID THERE WOULD BE NO MORE SNOW. WELL I CAN TELL THEM IT'S THREE FEET DEEP". And so on and so forth. How can such cold weather be possible, if we are supposed to be warming? That's a fair question, so let's have a more in-depth look.

L - They told me it was getting warmer and just look at it! I want my money back!!!

In scientific terms, such arguments as those in capitals above are pure straw men - setting up a false premise and shooting it down again is a favourite if not entirely honourable debating tactic as old as the hills. I have followed the published literature on climate for a long time and I can confidently state that there is not one peer-reviewed paper that predicts the total loss of the Greenland or Antarctica icecaps now or in fifty years' time - their total melting would take many centuries and it will not be a linear process. Likewise, there is not one paper I have seen that forecasts the abolition of cold weather in winter by 2010, 2020 or 2030. If such things have been said, they have been said by sensationalist media outlets, completely immune to the pre-publication review procedures that screen out many errors from scientific papers. Thus, a single, 1000-word newspaper article can contain ten times the number of errors found in the 2800-page IPCC AR4 report, not that anybody seems to mind!

Let's get this into some kind of perspective here. Climate models suggest that global average temperatures will (under a Business As Usual scenario) rise by 3-6C over the next 100 years or so, with a much greater warming at high latitudes. OK then - gameplay time - let's give the Arctic a 6-12C imaginary  warming right now. Over much of the Greenland interior on a February morning, the temperature will be between -20 and -30C. Knock even 12C off that and it's -8 down to -18C, which is still bloody cold in my books! Let's continue playing and give the UK the full +6 degree imaginary warming. We have had severe frosts this winter with minima between -10 and -20. So with +6 we still have the potential for -4 to -14 and that's with the full warming, a hundred years from now. The message is simple: winters far into the future may be less cold, but spells of cold weather are not going to go away just yet! They will still occur when the correct arrangements of the jetstream and high and low pressure systems are in place.

So far, in fact, the amount of increase in average global temperature has been a little below 1C. We are right on the lower rungs of the ladder that stretches up above us into our uncertain future.

HOW DOES SNOWMAGEDDON FIT INTO A
SUPPOSEDLY WARMING WORLD?

As a severe weather enthusiast, I've done a bit of reading-up on these and it's interesting to see how they formed.

These were classic Nor-easter storms, as the synoptic chart for February 6th shows (L). They occur when low pressure systems deepen over the eastern, Atlantic coast of the USA, causing a long-fetch NE airflow in off the sea and into the cold Eastern states - and that's the key.

We have a similar phenomenon in the UK that brings prolonged rain - the Warm Conveyor. In our case, this is a long-fetch SW airflow that comes in from the mid-Atlantic and runs into our hilly western side. The last significant one, in November 2009, brought flooding right up the western seaboard, and in the Lake District, record-breaking rainfall and disastrous flooding at great personal and economic cost.

To have heavy prolonged rain or snow, the air coming into your area has to be carrying plenty of moisture. Whether it's rain or snow is down to having the right temperatures through the air profile, and as we know over here it doesn't have to be -15 before it will snow - in fact the phrase "it's too cold for snow" is something that one often hears.  No - it's that moisture that is critical in both cases.

How would even slightly increased temperatures influence things here? Well, there are two issues, both of which are highly sensitive to any temperature increase. Firstly, if you warm the sea surface up, what happens? Well, anybody who has noticed steam rising from a warm bath will have seen evaporation occurring, and the warmer the water, the greater the rate of evaporation. As is the case with the laws of physics, this applies whether it's a warm ocean or a steaming hot bath.

Secondly, amongst the properties of warmer air is one critical one in this context: warmer air can carry more moisture. It can pick it up over the ocean and transport it hundreds of miles. How does this work? It's the nature of the equilibrium between the water (the liquid phase of H2O) and its vapour (the gaseous phase of H2O). In air, these two phases exist in dynamic equilibrium, in which the gaseous molecules are combining and condensing to form liquid, and simultaneously the liquid molecules are evaporating to form gas. These processes are occurring at the same rates, so that the proportions of liquid and gas remain the same. Now, if you alter things by warming that air up, obviously you warm its contents including the water: then the water molecules, both liquid and gas, have more kinetic energy: in turn this hinders the condensation of gas-phase into liquid and helps the liquid-phase to evaporate. This imbalance is addressed by increasing the concentration of liquid-phase water until equilibrium is once again reached at a higher equilibrium concentration - or vapour pressure as it's usually known.

Now, develop a strong low just off the East coast of the USA, with a high pressure area over central Canada, and what happens if the sea and the air over it are just a bit warmer?

Sea temperatures can be examined at sites such as http://www.oceanweather.com/data/ where the warm Gulf Stream current can easily be seen, traveling up the coast as far as Cape Hatteras in North Carolina and then veering in a more NE direction. The coast to the north (i.e. from Virginia up to Maine) is hugged by the cold Labrador Current, but less than a couple of hundred miles off Rhode Island and we have pleasantly warm water of as much as 20C or more even at this time of year.

Warm up that water, warm the air above it, even by a little bit, and even more moisture will be picked up and transported towards the coast. Slam that warm moist air feed into the cold Arctic air circulating the Canadian High and hey presto! Snowmageddon!

So therein lies the problem for the residents of these states. The warming does NOT make it too warm for snow, but instead it makes the atmosphere in the critical area out over the ocean moist enough for lots and lots of snow when that air moves inland and meets the cold. As with our record-breaking Lake District flooding, it is very tempting to suggest that these events are part of a trend that is emerging from the noise.

However, there's an old British saying: "Two swallows do not a Summer make". This means that two events, even though they appear to be indicating something, are insufficient as yet to be absolutely conclusive on their own. Climate models predict such events to become more frequent and the basic laws of physics predict that they will occur in a warmer system. There will come a point when a clear signal in terms of frequency of severe rain/snowfall events does emerge from the noise, but because climate operates on multidecadal timescales, you would need to look at a minimum of 30 years to make an authoritative conclusion based on observations alone.

BUT WHAT ARE TRENDS?

That trends in climate tend to have greater significance over longer timespans can be difficult to get one's head around. But this is an excellent analogy that should help (with acknowledgement to John Russell on Skeptical Science - link below):

You're standing on the beach, watching the waves, and trying to work out whether the tide's coming in or going out. Now, you can see that some waves look bigger, some smaller, some coming nearer to your feet and some further away (this being the noise), but after 25 waves in just under a minute it's not clear what's occurring either way: the noise (waves) is hiding the trend  (tide) because the time period is insufficient for a statistically significant trend to emerge. So you sit in your deckchair by the water's edge for half an hour, during which 750+ waves come ashore, and at the end of that time you find yourself sitting in six inches of water. You have discovered the statistically significant trend, which in this case is that the tide is coming in!

That's why 30 year+ timespans are used in determining significant climate trends: although the beach analogy describes one example of a trend emerging from the noise, in the case of climate the trend is much more subtle than the tide coming in and the noise much more intense. A favourite contrarian gambit for some time now has been to plot temperatures starting with 1998 (an anomalously warm year with the most intense El Nino of the 20th Century), because that neatly generates a flatline or an apparent slight cooling, depending what year you end on. But due to the short time period - well under 30 years - it does not tell you anything statistically significant - it is a pointless exercise and a practise known as cherrypicking, taking the big positive piece of noise that was 1998 as the starting-point. Fail.

Of course, a flat calm day with no swell would let you watch the tide trickle up the sand and you could make your trend conclusion in much less time - but as a consequence of weather, the highly variable El Nino/La Nina cycle, variations in aerosols including volcanic dust and so on and so forth, you don't get the equivalent of a calm day with no swell in global climate.

LOOKING AHEAD.....

Looking ahead - I think that's one of the biggest problems with climate change and its public image. It always seems to be about things happening several decades away - and the worst predictions concern the later decades of this century, so that they could only be witnessed by a small percentage of those of us who engage in the debate right now. But already we are seeing a hint here, a hint there, that there are unusual things going on. Reading the literature leaves one with the strong conviction that there will surely come a point where, to all but the most diehard political activists, it can no longer be shrugged off, dismissed as a leftist conspiracy to raise taxes or whatever. Unfortunately, in financial terms by that point it could make the banking bail-out look  like the bargain of the year!

The problem of the PR disaster - over-egged media alarmism, leading people to expect total chaos right now and, in the general absence of that, leaving them often feeling rather short-changed, is something that the media need to reflect on. But swinging to the opposite extreme does not help. It is taking the easy way out. Nobody wants to be told their lifestyle is harmful to the general future prospects for civilisation: in contrast it's very easy (and in this case intellectually lazy and downright irresponsible) to tell people exactly what they want to hear.

Of course, there is another very good reason for a transition towards a low-carbon economy: that concerns the future availability of fossil fuels. We are at or very close to the peak in conventional crude oil production - i.e. transport fuel for most of us. Gas will peak sometime this century, coal sometime this or next. With the latter two, the question is probably more along the lines of how much we want to leave for future generations; with oil we are already seeing problems both in the global economy and within the oil sector due at least in part to oil price volatility since 2007. We will continue to use fossil fuels but we need to phase in alternatives steadily: the alternative is to walk blindly into a "supply crunch" event with profound and severe consequences for most of us. Perhaps, though, the answers lie in carrots, not sticks. The business and employment opportunities that exist in the development of a lower-carbon economy are vast: furthermore, the value of the fossil fuels as chemical feedstocks is I would suggest likely to go up significantly through time.

So: avoiding an oil supply-crunch, generating extensive new business and employment opportunities and increasing the value of the remaining fossil fuels PLUS avoiding the worst climate-related issues in the latter part of this century looks - to me, anyway, like a win-win-win situation. Whether we actually achieve all of that will be a matter for history to decide.

To finish with, here are a few climate-related sites I like. Some are more concerned with the science, some with the politics, but all are worth a read, and all link to other sites of interest.