Tuesday, March 23, 2010

Odds for a record year hit 2-1 on Intrade

Since I penned this post, Intrade's odds of 2010 being the hottest year in the instrument record have risen from 50% to 66%.

It's a little hard to know why this is happening. Low volumes (meaning few traders making few trades) are the Achilles' heel of Intrade, and they may be a factor here. On the one hand, we are certainly on pace to break the record. Intrade uses the GISS surface data, and while both January and February were second-hottest overall (at +0.88C and +0.91C, respectively), this was only because of two crazy hot months in two different years (1998 and 2007). What do I mean when I say "crazy hot"? January 2007 was the hottest month in the instrument record with an anomaly of 1.08C. Not the hottest January -- the hottest month, period, in 131 years of records. The third hottest month, ever, was February 1998 (+1.01C). The second hottest -- as luck would have it -- was a March (March 2002, +1.02C). So March 2010 may not break the March record either, but dollar to donuts (looking at the daily satellite temperatures here) the first quarter is going to set a record.

But even so, it's early days yet; we only have data for three months of the year, and the third month still has a week to run. Why are the numbers so high?

It may have to do with the fact that the current El Nino is just hanging in there, and is now expected to continue through Spring. Or it may be the fact that we are emerging from the solar minimum, as I discussed in this post. Or perhaps people are looking at local forecasts, like those predicting the hottest summer ever for the UK.

It's been five years since the last "hottest ever" year, so we can expect the the underlying baseline temperature is about 0.1C greater than it was then (half the decadal trend of 0.2C.) By itself, that's not enough to give us a two-thirds chance to break the record: the short-term fluctuations in the climate are greater in magnitude.

Maybe all these factors together give the savvy Intrader a confidence in a record-breaking 2010 that I, for one, can't entirely parse. Or maybe the contract is a little overpriced. But for whatever it's worth, the money in the market says the odds of a record year are 86 times greater than random chance without a warming trend.

Why is conservatism unable to come to grips with climate change? Part one.

Denialism is primarily a disease of social conservatives. The recent decline in those professing belief in the science is well-known, but what has been less well-emphasized is that almost all of change is a result of a dramatic fall among conservatives:

Four out of ten conservatives who believed in climate change in 2008 no longer do, despite the fact that 2009 was the second-warmest year on record, and the Oughts the hottest decade. Conservatives were equally split on the reality of climate change in 2008, but the worm has turned. It may be useful to consider the forces which seem to have given conservatism a violent shove away from the physical realities of our world.

One of the most important things about this political dichotomy is that it reflects politics as it is practiced in our country today; it reflects the political outlook honed by the Bush administration, which heaped scorn on the "reality-based community." It is a politics that is committed to contesting every point, however trivial, attacking every proposition, no matter how commonsensical, and used a hate-filled vocabulary organized around conspiracy at the back of which are crude dog-whistle messages that the other side is not like us.

I know that it seems like an eternity we've been living with these politics, but in fact, it's only been a few years. Swiftboating, first used to target John Kerry, came on the scene in 2003. In hindsight, it was a foretaste of the strategy conservatives would used to target Obama (Kenyan! Socialist! William Ayers!) and healthcare reform (death panels! socialist!) as well as climate change.

What is characteristic about these attacks is that, like the show trials of Trotskyites, they barely pretend to address the facts of the issue. Often, they seem almost defiantly sloppy. They offer not arguments to convince the skeptical, but thinly-veiled excuses to believe what the subject has always believed about "them." The believers must no on some level that they are being asked to participate in a political lie; not many of Sarah Palin's listeners can actually have believed that the government was planning to set up "death panels" to try the elderly or infirm. But they believed that bad people were up to no good; and by cheering and repeating this obvious lie, they were serving their tribe in good stead. In the 21st century, people are not just passive recipients of bias information; propaganda has gone viral; our self-serving narratives emerge from the cloud.

Denialism is comfortable to conservatives because they have gradually acclaimated themselves to the practice of making the facts bend to the ideology; of embracing whatever narrative gives aid and comfort to the tribe, regardless of how far-fetched it is. This dynamic has been assisted greatly by the internet. No longer does a conspiracy theorist have to air their views in mixed company when they are less than fully formed and hardened in place.

No longer must one push and prod the facts as presented by newspapers or TV to extract those elements which support the conspiracy theory. In the harsh light of 2010, the idea of "spinning" the news is as much an antique as a manual typewriter. The power of the internet and friendly outlets like Fox is that they create their own facts, almost their own world. The facts created are immediately affirmed by like-minded individuals, and arguments are disseminated to those less capable of sophistry under their own steam.

Once, an ideological fugue like this could only exist where there was an entire state apparatus to support it, as in a totalitarian state. Today that's not necessary: the screaming crowds, the nasty slander cumulating in show trials, the censorship of dangerous criticism (whilst tolerating voices that make the other side appear absurd) -- all these things can be created within the right-wing echo chamber (and have their more modest and more primitive equivalents on the far left). And unlike totalitarians, they do not require any coercive force to keep the drones inside the lie: they stay within the circle of their own accord; it's where they feel most comfortable. After all, outside are dangerous people that hate us, that want to seduce us with lies and ruin us . . .

I realize this post has become less about the why, and more about the how, but the how is important too. Because despite my less-than-affectionate perspective on conservatives, they are not the only ones responsible for the present state of affairs. We are all at fault; we have all allowed our public discourse to make truth subject to ideology. The media have gone right along with it; the transition of news organizations from the gatekeepers of facts to the purveyors of branded political and social commentary has made them partners in this degradation. The public, by eagerly consuming partisan rhetoric, and letting themselves become caught up in who was winning the day, winning the issue, winning the race, are also pushing our society along this path to total disconnection with objective truth.

But why climate change? Why did global warming became, along with healthcare, the major lighting rod for conservative mythmaking? After all, if anyone ought to understand that preserving our environment for our children and the generations to come is a moral imperative, it's a conservative. If anyone should understand that radical change to an environment that has sustained us for ten thousand years of human civilization is likely to do severe harm, it's a conservative. If anyone should respect the opinions of the vast majority of working scientists and national and international scientific federations, it's those authority-loving conservatives.

I'll explore the reasons in part two.

Saturday, March 20, 2010

Idiot of the week: Bob Carter, data pervert

Story here. It's amazing. Carter got caught switching from one source of temperature data to another when the first showed too much warming -- this caused an abrupt drop in temperatures which was concealed in the graph by placing it at the point the two-page spread jumped from one page to another.

This manipulation was not in service of Mann's hockey stick (still holding up nicely after multiple reviews, thank you very much) nor was it discovered by purloining hacked e-mails. Instead, it was crafted to further the lie that “We have shown that internal global climate-system variability accounts for at least 80% of the observed global climate variation over the past half-century.”

This is clear-cut scientific malfeasance in service of a political agenda -- namely, as Carter puts it that since, “The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions,” curbing such admissions should be off the table.

Has this liar been the beneficiary of Mr. Watt's denial boosterism? You know he has! In fact, Watt's reposted a Carter screed called -- I'm not kidding -- "The Science of Deceit." I guess we should see that title as less tsk-tsk and more how-to. A sample from the man who just got caught red-handed manipulating data to hid warming:

"A well-accepted aphorism about science, in the context of difference of opinion between two points of view, is 'Madam, you are entitled to your own interpretation, but not to your own facts'."

"In the face of such attitudes, which treat the established mores of scientific trust and method with contempt, . . ."

"So much for data perversions."

So much for data perversions, indeed. You want fries with that projection?

EDIT: This may not be the first time Bob Carter has fudged his data . . . or even the first time he's been caught at it. Consider this interesting email, found at Skeptical Science:

When I emailed Bob Carter querying about his data in the article above, this was his reply (28 Jun 2007):

"By mistake the graph that was reproduced in the Telegraph article was for the middle troposphere. Though it does not materially affect the argument or conclusions, I am embarrassed by it because it can be made to look as if I was pulling a swiftie - which I wasn't (intending to)."

I'll take Carter at his word that it was an honest mistake, although I've noticed he continues to state satellites show little to no tropospheric warming.

In 2007, Carter swaps a graph from the middle troposphere into an article about the lower troposphere, hiding the warming trend in the latter. Maybe he's not dishonest, just terminally sloppy, but don't these graphical "mistakes" -- which always seem to conceal warming -- seem a little similar for comfort?

Idiotic idea of the week: mothballing DSCOVR

In 1998, vice president Al Gore proposed, and NASA designed and built, the Deep Space Climate Observatory (DSCOVR) satellite, whose purpose was to directly observe several key measures of climate change:

In addition to an imaging camera, a radiometer would take the first direct measurements of how much sunlight is reflected and emitted from the whole Earth (albedo). This data could constitute a barometer for the process of global warming. The scientific goals expanded to measure the amount of solar energy reaching Earth, cloud patterns, weather systems, monitor the health of Earth's vegetation, and track the amount of UV light reaching the surface through the ozone layer.

While NASA's Inspector General questioned the cost/benefit ratio of the project (quite rightly -- that's his job) the National Academy of Science, queried by Congress, found the mission to be "strong and scientifically vital."

Nevertheless, the satellite was mothballed for eight years under the Bush administration, and remains in limbo today.

The information the satellite would provide is phenomenally important, and should be important to "skeptics," as well. Directly measuring the Earth's radiation budget (energy in versus energy out) gives you a direct, observed value of global warming, magnitude and sign. By tracking our albedo, vegetation, and cloud patterns, the satellite would monitor three of the most important feedbacks in climate change.

If you want an easy way to tell who not to trust in a scientific debate, it's the side that's afraid of better measurements. Those that want to softpedal global warming or deny it entirely always claim frustration with the lack of clarity (as they see it) in the science, but where's their drive to collect observations and achieve a better understanding? DSCOVR waits in a warehouse, but climate change isn't waiting.

Friday, March 19, 2010

All Things Methane: Part Two

The sources of atmospheric methane are many and varied:

Some are natural (i.e., wetlands) and some are anthropogenic. Methane levels have doubled since the pre-industrial era, so the anthropogenic emissions, which have increased, are having a significant impact. That doubling, to review, adds about half again to the forcing of the excess CO2 in the atmosphere (while methane is a more potent greenhouse gas than CO2, its concentration in the atmosphere is much smaller.) Anthropogenic emissions break down as follows:

Much of the excitement about methane, and the source of the recent flurry of interest in methane (see Climate Progress, Dot Earth, and Realclimate) is the stored methane around the world, locked up in permafrost or deep under the ocean.

Natural processes have created carbon-based deposits of many kinds; coal, oil, "natural gas" (which is methane) and others. Methane hydrates, which I promised to explain last time, are deposits in cold water and usually under great pressure, composed of methane molecules (original released by aquatic bacteria) trapped in a matrix of frozen H2O (methane clathrates are the same thing -- a "clathrate" is just the generic term for anything frozen inside a matrix of anything -- a "hydrate" is a clathrate in which water is the matrix. Methane hydrates is the more usual term today, but "clathrates" come up, as we see below.")

The reason these deposits get people excited is that, since obviously they depend on the cold in order to stay frozen, that they may be destabilized by climate change. Estimates of how much of this stuff there is vary widely, but the lowest estimates are very high; 500 to 2,500 billion tons.

Suppose 1% of that leaked out per year. How bad would that be? Taking a middle estimate of 1,500 billion tons, that would be a release of 15 billion tons. That would approximately double the amount of methane in the atmosphere in a single year, doubling the forcing of methane (which has already doubled once). This would continue in the following year, and the year after that. Assuming no acceleration, and assuming methane decays after ten years, on average, we would end up with 10-15 times at much methane in the atmosphere as we have now, which would lead to an almost instantaneous warming of 1-2 degrees C, plus an additional 1-2 degrees as the long-term feedbacks kick in.

Unfortunately, that methane does not just vanish as it decays -- it turns into CO2 and stratosphere water vapor (a powerful greenhouse gas), such that after ten years, in addition to the warming from the methane, we've also added water vapor and significant amounts of CO2 (roughly 50% over and above our anthropogenic emissions).

The above is probably much too simple, as it ignores the local effects (the most likely location for massive methane releases is in the Arctic, which could thereby lose more sea ice, changing the earth's albedo) and also ignores methane sinks. However, it is enough to give a flavor of why people are concerned.

Some are more concerned than others, pointing, for example, to mass extinctions in which the release of frozen methane deposits may have been the culprit (the clathrate gun hypothesis). On the other hand, climate scientists point out that we really don't have evidence or a convincing mechanism for the sudden release of even 1% of these deposits -- yet. All of which leads us to the reason this debate is heating up right now: scientists who went to the Arctic to study the possibility that methane frozen in undersea permafrost might someday be release were shock to discover hundreds of methane plumes across the Arctic seabed. Their findings quickly settling the question of "Will this happen?" and made the key questions "How long, how fast, how bad?"

I'll talk about those key questions in part three.

Sunday, March 14, 2010

Think global warming is a myth? Head over to Intrade and make some money

Over at Intrade, the odds are running five-to-one in favor of 2010 being one of the five hottest years on record (as measured by GIStemp). If you believe that there's no warming trend, global cooling has begun, etc., this should be easy money if you're right. The odds of 2010 being one of the five warmest years by simple chance variation is 5/131 (3.8%). But Intrade is pricing the contract as if the chance were 82% -- greater by a factor of twenty!

Or maybe you want to play it safe -- betting only against 2010 being the hottest year ever recorded (see the new widget on the right). The odds of this happening by chance are only 1/131 -- 0.76%. But as of tonight, Intrade has it as an even-money bet! All you have to do to double your money is to bet (and be right in betting) that this will not be the hottest year since record-keeping began in the 19th century. Easy!

Of course, January and February were both the second hottest months ever recorded in GIStemp. So the short end of the bet is not looking good. But be bold! Clearly investors have bought into this whole "warming" scam and are ready to put their money are the table.

Aren't you?

New paper: air quality benefits migitate the costs of carbon taxes

An interesting paper in Environmental Research Letters ("Implications of incorporating air-quality co-benefits into climate change policymaking") finds that the benefits to human health from reducing air pollution are a very significant benefit of reducing fossil fuel burning, yet are rarely considered in the cost-benefit analysis of measures to reduced carbon emissions (of which by far the most direct and effective would be a simple tax on carbon emissions):

It is well known that many strategies for reducing greenhouse gas emissions also decrease emissions of health-damaging air pollutants and precursor species, including particulate matter, nitrogen oxides, and sulfur dioxide. In a survey of previous studies we found a range of estimates for the air quality co-benefits of climate change mitigation of $2- 196/tCO2 with a mean of $49/tCO2, and the highest co-benefits found in developing countries.

By comparison, an effective carbon tax that would bring our emissions down very sharply (>80% reduction) is estimated at between $75 and $300 per ton. What this study suggests is that apart from any need to mitigate climate change, the benefits to human health alone suggests we ought to be taxing carbon emissions at around half that rate purely to reflect the real cost to the health of society from the crap the fossil fuel economy spews into the air.

Current CO2 emissions world-wide at presently around 28 billion tons a year. Suppose we could reduce that to 3 billion. The cost savings in reduced disease burden would be in the range of about $750 billion to $2 trillion dollars per year. Right on the mean ($50 per ton) we would save 1.25 trillions dollars per year, which is greater than the total cost estimate for reducing our CO2 emissions.

It's often been said that if the deniers are wrong, and we do not act, the result will be a catastrophe, while if the scientists are wrong, and we do act, the worst that will happen is a world with cleaner air, more efficient industries, and less dependence on fossil fuels. This study shows illustrates that point with hard numbers that show that even taking only one aspect -- cleaner air -- of the secondary benefits of discourage the burning of fossil fuels dwarf the cost of transitioning to greater efficiency and other energy supplies.

Addition to the blogroll: Wott's Up With That

This outstanding blog -- found in my obsessive late-night climate Googling -- examines the mendacious WUWT post by slimy post, cleverly dismantling Watts' reality distortion field with facts, context and humor. Check it out!


Minor myths, part 2: "Science will save us"

From Terry J:

"Evolution is accepted by everyone but the climate types. The entire earth history says it will change, but does not say any given species will like the change. Adaptation is considered a key factor in evolution, but apparently no longer functions."

Katherine offers:

"It’s a mistake to try to control CO2 to the detriment of prosperity when that prosperity is what would enable people to adapt to climate change–whether for warmer or cooler."

The idea behind this meme is that science, aided by the invisible hand of the marketplace, has overcome all obstacles to achieve our current prosperity, and that to argue that climate change is a serious problem that must be addressed is to foolishly ignore the track record of science and innovation in moving society ever forwards. Science will save us.

One way to examine this thesis would be to look at societies that failed in the past, and ask if we are immune to the same failings because we are richer, with more knowledge of the natural world and better technology. A good examination of this can be found in Diamond's Collapse. Another would be to compare the anticipated effects of global warming with a reasonable projection of the technology we are likely to have when, say, sea level rise threatens every coastal city, town and village in the world with inundation.

But here at theIT, we try to keep things simple, and leave the heavy stuff to the real scientists: see the blogroll for a list. ("The Science of Doom," in particular, is an amazing blog that deserves more traffic. And of course RealClimate, they just go from strength to strength over there.) But here we are. Is there an easier way to refute this argument than to delve into the details of the scope of the problems and the powers and limits of science?

In fact, there is. The we need not dispute the literal truth of the statement, in fact, to do so. Will science save us? I put it to you that science has saved us. It's done.

Consider a society which collapsed due primarily to self-inflicted ecological damage: Easter Island (Diamond again!). They deforested their island, lost the ability to build canoes (because they had no suitable wood), lost much of their ability to fish (no canoes), lost soils to erosion, and eventually lost most of their population and civilization, with evidence of widespread cannibalism.

In the time this was happening to them, the Easter Islander did not know what the deforestation would do, had little concept of soil erosion and other ecological disasters, and had no records or history of societies confronting similar challenges, successfully or unsuccessfully.

Consider our situation. What has science done for us so far?

1. Science has clearly demonstrated the world is warming, and that dangerous consequences will follow from that. Without science, we would not even be able to identify the problem (as happened on Easter Island.)

2. Science has determined the cause of the warming (man-made greenhouse gases).

3. Science has provided us with technologies that allow us to address the problem (which requires us to greatly reduce our output of GHGs) without sacrificing our modern lifestyle: Because of science we have nuclear, solar, and wind power; we have efficient insulation and low-drag vehicles; we have trains and buses; we have the internet.

Science has identified the problem, found the source of the problem, outlined a solution, and provided technology to make the solution relatively painless (an estimated two-tenths of a percent of GDP to transition to a low-carbon economy).

Global warming deniers want to position themselves as optimistic people with great faith in science and the future, but there's an old joke about faith that applies here:

A God-fearing man falls from a ship into the ocean. He is frightened, but he knows God loves him and will save him. He prays to God to save him and focuses on his absolute belief that God will save him. After a while a fishing boat comes by. "Here, grab this line and we'll pull you out of the water!" the captain says. "No, thank you, but God is going to save me" the man says. So the boat leaves, and a rich man's yacht comes by. "Here, grab my hand and we'll pull you in!" they say. "No, thank you, God is going to save me" the man says. Finally a Coast Guard cutter comes by, but the same conversation is repeated again.

Finally the man drowns. And because he is a good man, just a little thick, he goes to heaven and comes before God. And he asks him "God, I loved you and believed in you so much. Why didn't you save me?" And God looks at him and says "Didn't you see the fishing boat, the yacht, and the Coast Guard cutter?"

There is no question of whether science will save us: science has provided us with all the tools we need to save ourselves. Are the solutions science and technology provide free of expense or effort? (Are we talking about science or magic?) Do they alleviate the need for preparation and foresight? A parachute does not work unless you put it on -- preferable before you jump out of the plane. Antibiotics don't work unless you take them. And science won't solve global warming unless you listen to the scientists and use the tools that science has provided to actually solve the problem.

Friday, March 5, 2010

All Things Methane: Part One

Given the trouble people have understanding CO2 as a greenhouse gas, it's not surprising methane is confusing. It's a greenhouse gas, OK so far. It is either 25, or 30, or 400 times as powerful as CO2 as a greenhouse gas. Yet, we worry more about CO2. Its levels have doubled since pre-industrial times, but when you read about it, what mostly has people's knickers in a twist is the natural release of methane from the environment. How is that our problem?

And while we're on the subject, what about all those different forms of stored methane in nature? You've got your methane clathrates, methane hydrates, methane locked in permafrost, methane bubbling up from the tropics – I mean, what the hell?

I wish I could say everything clears up when you learn a little bit about methane. Unfortunately, it's not that kind of subject. Questions lead to other questions, like: why did methane concentrations double in the industrial age, level off for ten years, and then start rising rapidly again three years ago? (See: http://www.treehugger.com/20090306-methane-concentrations.jpg.)

Let's start with what methane is up to in the climate today:

We can see that the forcing of methane (CH4) is about half that for carbon dioxide. Why is that, if it is such a powerful greenhouse gas? The answer is that there's a lot less of it. CO2 is measured in parts per million (about 390), and methane is measured in parts per billion (about 1,750). So CO2 is more important because there is more of it.

The other reason we care more about CO2, and the reason you hear such different numbers for how much more "potent" methane is relative to CO2, is that CO2 hangs around in the atmosphere basically forever (hundreds to thousands of years) and methane breaks down quickly (about a dozen years). So the big numbers (400 times more powerful) refer to a molecule of CH4 vs a molecule of CO2, and the smaller numbers (25 times, 50 times) refer to the fact that CO2 is weaker as a GHG, but hangs around a lot longer.

This matters quite a bit, because of feedbacks. Positive feedbacks (things like loss of the sea ice in the Arctic, leading to a change in albedo and more warming, or warming of the oceans, leading to a reduced ability to store dissolved CO2, more atmospheric CO2, and more warming) mean that front-loaded warming is more dangerous than "slow and steady" warming, even leaving aside the fact that warming sooner rather than later leaves less time for adaptation. If warming today triggers more warming (and it seems very likely that is does) then warming from methane follows those rules of compound interest earnest financial planners try to teach you: warming now (like saving now) leads to bigger results, because it triggers positive feedback (the "interest") which causes warming, which leads to more feedback, which leads to more warming (the interest earns interest; this is the "compound" part.) So a spike in methane levels could be very dangerous; by giving the climate a hard shove for the 12 years or so it is in the atmosphere, methane can set in motion processes that will be warming the climate after the initial bolus of methane is long gone.

Should we be concerned about the possibility of such a spike? Unfortunately, yes. To understand why, we have to delve in to the different forms of stored methane and how they become unstored. I'll explore that in part two.

Wednesday, March 3, 2010

Hat tip

John Quiggin goes to town on the "no global warming since 1995" meme in an all-around awesome post: Four lies and an empty set. So even though on his worst day he has ten times the readers this blog has or is likely to have, I'm going to advise any of the handful of people who may have wandered in here by mistake to go read his stuff -- it's great.

Tuesday, March 2, 2010

Minor myths: "The Arctic sea ice is almost back to normal"

The big dogs do a great job of cataloging the major denialist talking points, the ones with legs, the major hallucinations. See Realclimate's stuff and Skeptical Science's pages. But the work is never done; deniers change memes as often as they change their socks, and for the same reason: at the end of the day, they stink to high heaven.

So this is the first in an occasional series on the minor talking points of the deniers. This week: the claim that after hitting an all-time low in 2007, Arctic ice has "rebounded" and is now "near normal."

You find it on AccuWeather:

So far we have two years of recovery from the 2007 melt. Will it surpass 2007's melt or will it return to normal?

You find it in Watt's echo chamber:

In 2007 the winds caused an anomaly that has been recovering ever since.

[And star idiot Steven Goddard weighs in:]

Ice area is normal and well ahead of 2007 or 2008.

Thirty seconds of looking at the actual data gives the lie to the talking point:

We are running 720,000 square km below the mean. That's far from "normal" or even "near normal." What about the "recovery" part of the myth? Consider the yearly sea ice minimum, still, in 2008 and 2009, far below average levels:

When you look at the chart, you can see what's happened. In 2007 the bottom fell out. No one knows exactly why, but it was a record-shattering year. In the ensuing two years, the summer extent is slightly higher, but every year since 2007 has been far worse than every year prior to 2007. That's a critical point. 2007 remains, so far, an outlier, but the ice has not come back from that decline. Deniers are ignoring that in trying to imagine a recovery to near-normal levels. 2008 and 2009 were the second- and third-worst years for the Arctic ice on record.

Aficionados of idiocy will note that this is the same fallacy that denailists use to argue that 2005 hottest year on record = cooling for the past five years (Sure, and any day Kobe Byrant scores less than 81 points a game (his record, believe it or not) we can say his career is in decline).

We can expect more nasty surprises like 2007 ahead, but in the meantime, we can be buoyed by the denialists' optimistic view that any year that does not set a new record -- whether for temperature or sea ice or glacier loss or whatever -- must mean the trend has reversed itself.

Monday, March 1, 2010

End of the solar minimum

February 2010 was the first month in three years in which the Sun has sunspots every day of the month. This is a sign of the end of an unusually long and deep "solar minimum" -- which is the term for the lower portion of a regular eleven-year cycle of sunspots. In 2009, there were 260(!) days without sunspots. Nevertheless, 2009 was tied for the second-warmest year in the instrument record.

The influence of solar variability on the climate is modest -- the sun's intensity varies by a maximum of about 1 W/m^2. But in the short term, especially given the likely persistence of an El Nino through Spring, the upswing in solar radiance may contribute to record-breaking warmth. January and February 2010 were the hottest and second-hottest months in the satellite record, respectively -- which likely makes them among the hottest in the last 1,200 years.