Of Mountains and Molehills

Illustrated by Karen Wehrstein

The recent cold January in some parts of the world kicked up quite a ruckus in the blogosphere over climate change. Michael Masher, the author of the article on Daily Tech critiqued here a few days ago, and I decided to team up for a joint effort which, we sincerely hope, will be fun to read and produce interesting discussion and debate. Mike’s post will be available in the next week or so.¹

At issue was the data from early 2007 and 2008. I guess you could say it was the best of Januaries, it was the worst of Januaries. The numbers on the zig-zaggy black line are the deviation by month from the average global temperature for the month in question in degrees Celsius (Source GISS Land Sea Temperature Record). Jan 08 at 0.12 means it was twelve one-hundredths of a degree warmer than the average of all the Jan’s.

Now, Jan 08 at 0.12 degrees above the baseline is cooler than recent Jans. You have to go all the way back to 1989 to find a cooler one. But it is warmer than the baseline, that's why it's a positive 0.12 instead of negative - 0.12. Contrast that modest 0.12 increase with the 0.87 of Jan 07, one year earlier. Jan 07 is the largest (And warmer) divergence in the entire monthly GISS record going back to 1888.  The steep downward slope of that blue line is much more a product of an exceptionally warmer than average Jan 07 than a cooler Jan 08. But lines, like conclusions, drawn hastily between the two, dressed up with headlines about record snowfall, sure can look like evidence for dramatic cooling, even though they’re a product of record warming, eh?

The green line from the Jan 07 record high to the average of all thirteen subsequent months is imo, a better representation of the annual data. And, if you drop off Jan 07 to get a true 12 month metric, shown in red, the mountain disappears, to be replaced with barely a molehill.

But, Michael asked a good question, one I'll address in this context: why was Jan 08 cooler than the dozen or more January’s before, and why was Jan 07 so blasted hot it sticks out like a sore thumb?

To understand a few of the factors that affect our global climate, think of a gas guzzling SUV sitting in a sunny summer parking lot with the windows rolled up. The sun’s whitish rays enter the clear windows and strike the interior where some of the light energy is converted to orange heat rays. But the glass windows which were transparent to sunlight are opaque to heat.

 
That egg is your biosphere. This is your biosphere on global warming. Any questions?

Alas, the heat is trapped bouncing around inside until, on a hot enough day, the interior temperature rises so high an egg will fry on the dashboard. This is the Greenhouse Effect, and global temperature records like the sample shown below left strongly support it's happening on a planetary scale. With carbon dioxide, water vapor, and other gases acting like windows which let sunlight in, but keep heat from getting out.

Of course, if less light gets in, that means less heat inside. That holds true of our red SUV -- regardless if the owner had the windows tinted, drove through a dust storm, or if heavy clouds cover the sun -- just as it holds true for the planet. Which segues nicely to an interesting period in the big picture.

The early uptrend halted from '42 to about '78. Why? One possible contributing factor is dust and smoke. World War 2 was in full swing, suddenly factories belched filth into the sky 24/7, artillery roared, bombs fell, entire cities were burned to the ground. Fire reigned, the great chemical equalizer, turning coal, gunpowder, cities and human bodies into smoke. And in the aftermath, when the guns thankfully fell silent, industrial activity surged to record levels on the heels of the worst global depression of the century.  

Aerosols and dust in the air act just like dirt on car windows and they’re not just manmade! Note the two lows in 91-92. That minima correlates perfectly with the June 1991 eruption of Mount Pinatubo, which was ten times larger than the Mount St Helen’s eruption a decade earlier.

So far so good right? Fire, already mankind's most trusted ally, will save us again! Lots of smoke from either volcanoes or coal plants or Chinese toy factories will block excess sunlight. Warming solved! Ah, but the same fiery emissions that carry blocking mist and soot into the atmosphere are also chock full of fire’s other offspring, notably greenhouse gases. They are much longer lived.

Natural processes like rain scrub dust from the air on the order of months. In fact the particles actually seed the clouds, producing more cleansing rain than would have been present in the first place. In the case of volcanic eruptions, this can produce deadly lahars, flash floods, rivers full of ash and mud which set up as hard as concrete when the water dries.

But carbon dioxide and other GHGs stay in the air long after the cooling smoke and aerosols have faded away. Years, decades, centuries later, some of them are still contributing to the global green house effect. If business as usual continues, eventually the temperature resumes its upward trend with a vengeance. In the end, fire is no answer, smoke is no defense: Venus is completely shrouded in thick clouds -- guarding a hellish landscape caught in a runaway greenhouse effect hot enough to melt lead. Luckily for us, we're a little farther out from the sun than Venus.

.... the sun ...

These days some climate change skeptics now tacitly accept that there is growing evidence for change, but claim it doesn’t mean we are the cause. True, human activity isn't the only thing affecting climate. But one of the more common factors they bring up is mysterious solar activity. This is implausible on so many levels I barely know where to start.

First, it’s Baloney. We’ve been watching the sun closely with modern telescopes for over a century. It's been examined in minute detail at every wavelength for several decades. Stellar models for stars like our sun suggest it will slowly heat up, roughly 10% every one-billion years. It faithfully exhibits an eleven year sunspot cycle, but to the best of our measurement ability, that cycle has a minimal impact on terrestrial climate and does not explain the observed long term warming trend. Outside of that, maybe the sun did some unusual things in the remote past. But since we’ve been paying close attention, we just do not see the sun brightening -- to the great benefit of every living thing on the planet I might add.

Second, it's no coincidence there's sunlight beaming into our SUV in the image. The Sun: That's what drives the climate, it's the engine. For crying out loud, it's the first thing researchers have plugged into models and forecasts since the dawn of climate science and weather forecasting. To seriously contend that thousands of climate scientists just up and forgot about the sun's fundamental role on earth's climate for the last forty-years, or that they don’t take the best, most up to date solar data gathered from dozens of surface and space-based observatories into account, is every bit as ludicrous as claiming NASA mission planners forgot about gravity.

Lastly, and this is the clincher (Or should be for anyone with the mental agility of the average five-year old), if we do see the sun suddenly embark on sustained, highly unprecedented warming binge, then I have some frightening news: we are in the deepest shit of all time. That would rank as about the most significant, utterly goddamn terrifying event in human history.  And were it true, saying it doesn't matter if we jump in and heat the planet like a sauna because, hey, the sun has gone whacky hot on us, is unusually, pathologically twisted 'logic' even for the nuttiest wingnut. It's akin to saying the best way to deal with an oncoming F-5 tornado is to sprint straight into the vortex. We can't control the sun, so controlling the thermal properties of our air, water, and land would be our sole option for survival on the surface of the planet if the sun suddenly starts heating up significantly.

So, if it's not the sun, or cosmic rays, or Underpants Gnomes, Michael Asher's question remains: why was Jan 07 so warm compared to Jan 08?

It’s a safe bet that after starting up your blazing hot car in the supermarket parking lot, the very next thing you'll do is roll down a window for circulation and turn on the air conditioner. The earth's heater/air conditioner is the ocean and the open window is its surface. Every now and then, especially when the air immediately above a large swath of open ocean is hotter (or colder) than normal, it can cause greater circulation between the deep water and the exposed surface. If a large volume of relatively warm water is brought to the surface in great amounts the heater is on. Vice versa for cold water welling up acting like an A/C. Bada-ding! From warmer one year to cooler the next.

My simplified analogy is part and parcel to an observed, much more complex phenomenon called the Southern Oscillation, more commonly known by the cyclic extremes El Nino and La Nina:

James Hansen (.pdf) -- The past year (2007) witnessed a transition from a weak El Nino to a strong La Nina (the latter is perhaps beginning to moderate already, as the ocean waters near Peru are beginning to warm). January 2007 was the warmest January in the period of instrumental data in the GISS analysis, while ... January 2008 was #40 warmest. Undoubtedly, the cooling trend through the year was due to the strengthening La Nina, and the unusual coolness in December was aided by a winter weather fluctuation.

There may be other factors involved, indeed, there almost certainly were. But right now, the Southern Oscillation along with the routine quirkiness of weather is about the best scientific explanation we have for at least part of the Jan 07 mountain and the Jan 08 molehill.

Step back for a bit and consider the layman‘s plight: It’s all terribly confusing for the casual reader! The industrial lobbies cleverly avoided the scientific arena and instead enlisted millions of unpaid spokesmen by laying global warming neatly across the right-left political axis (A small number of which find their way into my inbox on a daily basis btw). Sympathetic ideologues and hired guns produce a steady stream of misleading pseudoscientific nonsense and political rhetoric aimed at exploiting that confusion and ideological bias.

And yet, this progressive-conservative divide is not nearly so defined in the climate science community. Many earth and climate scientists from all parts of the world and the political spectrum accept that earth's temperature is rising and that human activity is one major contributing factor. Why? It's based unsurprisingly, on science. A few critical points:

1. The empirical evidence that human activity has and continues to add meaningful quantities of GHGs to the biosphere is overwhelming.

2. Recent observed increased global temperature and other events around the world are highly correlated to those increased GHG levels.

3. Past climate models which predicted that an increase in GHGs from human activity would produce defined, specific consequences have been borne out.  

There is a respectable minority of legitimate climate specialist who disagree with some of those points above in various ways based on what they feel are valid, non partisan reasons. But overall, those are the facts and conclusions of leading climate and paleo-climate researchers who sport a three decade track record of being right. Call them alarmist, massage them, accept or reject them, hang them on the wall with Gore's face on it and throw darts at them. But facts just don't care about ideology and climate doesn't respect political boundaries.

As far as the endlessly recycled alarmist label, what could be termed alarming possibilities arise from some of the latest models, done by research groups that have been vindicated on past predictions, indicating those effects will become more pronounced and may unfold more rapidly under business as usual scenarios than once thought. Worse, there may be completely new and even more ominous consequences ahead if critical tipping points are crossed, consequences well within the lifetime of some people reading this post.

One month or even one year does not a trend make in the big picture; the global temperature record is full of some respectable swings. If we took that single January '08 datum, averaged it into 2007, and then used the new 2007 average to generate a revised 100 year chart, the effect would be invisible. But what effect an unusually hot or cold time period does have still counts.

If the SO explanation is valid, and nothing else changes significantly, then the relatively cooler trend will soon end as Hansen states. Conversely, if it cools more, in hindsight if this marks the beginning of a multi-year cooling influence of as yet unknown origin and indeterminate length, it would be a fascinating development.

Climate researchers are scientists. Collectively, they eagerly examine any new data for or against human induced climate trends. They will not reject it for any reason, including those based on non-scientific, partisan, or business priorities. Nor would I: Indeed, as a Florida homeowner ten flat miles from the coast, a few scant meters above the Atlantic Ocean and smack dab in the middle of hurricane alley, I would much prefer the molehill over the mountain, any day.