Asking the Wrong Questions About Global Warming

I was once a TA for a physics lab that contained a large number of pre-med students.  One of the classes in this lab was designed to teach the concept of conservation of momentum by studying collisions between two hockey pucks of different masses on an air table.  I was asked by a very bright pre-med student "what does momentum look like?".  I was a bit baffled by the question but I explained how momentum was defined and how to calculate it for the hockey pucks.  He responded by telling me that my explanation about "transfers of momentum" made no sense because he didn't see anything move from one puck to the other in the collision.  I'll admit that I had to think for a while before I could answer that one and by that time the bright pre-med student had figured out a purely mechanical way to get the right answers and was no longer interested in my explanations.

A recent national poll found that:

44% of voters thinks human activity has a bigger impact on the long-term heating and cooling of the Earth’s atmosphere than solar activity does. Thirty-seven percent (37%) disagree and believe solar activity has a greater impact. Eighteen percent (18%) are not sure.

The problem with that question is exactly the same problem as asking what momentum looks like - both indicate a basic failure to understand the issue.  It's not as if climate variations are caused exclusively by people or the sun - in fact there are dozens of effects that can lead to large variations in the Earth’s climate including changes in solar luminosity, carbon sequestration by plants, solar activity, volcanic activity, and humanity burning carbon-based fuels.  Changes to any of these processes will lead to changes in climate.  The Sun’s luminosity changes on billion-year time-scales while human activity can have significant impacts over a few decades.  Solar activity is on an 11-year cycle, but to change the climate one needs to look at averages over many cycles, so again we’re talking about roughly 100 year time-scales. All of these processes are always changing the climate, so the question of which process has the bigger impact depends on the time-scale you are interested in.  It’s true that the Sun has been more active than normal over the past several cycles, but if you want to change the climate as fast as we’re observing, the Sun just isn’t up to the task.

Let’s look at how solar activity impacts climate. There are clear indications that long-term trends in solar activity can impact Earth's climate.  The leading theory is that when solar activity is at a minimum the average magnetic field strength in the heliosphere is lower than when the Sun is more active. Stronger magnetic fields are more likely to have strong interactions with high-energy cosmic rays (mostly protons and electrons).  When cosmic rays interact with the magnetic field they tend to produce synchrotron radition or undergo inverse Compton scattering.  Both processes reduce their energy, so the number of high-energy cosmic ray hits on the upper atmosphere goes up when solar activity is low.  When cosmic rays hit the atmosphere they tend to produce showers of thousands of particles with enough energy to ionize huge number of atoms.  These free electrons and ions catalyze droplet formation, thereby enhancing cloud formation.  More clouds mean that the Earth becomes more reflective (higher albedo for you astronomers in the audience) and therefore the Earth's mean temperature should go down.  There are some pretty clear indications from ice core and tree ring studies that indicate that when the Sun goes through an extended minimum, the Earth tends to go into an ice age.

The key here is no scientist thinks that solar activity does not impact climate - there is hard evidence that it does - however the issue is that it does so much too slowly.  If we look at the temperature record, we can see there are variations on a number of time-scales - but they key in discussing anthropogenic warming is that there is a huge spike in temperature on a very short time-scale that is unlike anything else in the data in the last century - which also corresponds to the time when human burning of fossil fuels and destruction of forested areas has peaked.

So at long last here's my point: asking if the Sun impacts our climate more or less than we do is completely missing the point.  The question we should be asking is if we are responsible for the recent spike in the Earth's average temperature.  Spoiler alert:  the answer is at least in large part yes.

Al Gore Responsible For Climate Change Deniers?

  

I read an interesting theory over at Cosmic Variance (you should all read that post) where Sean Carroll muses over whether Al Gore's politicization of climate change is responsible for so many denying climate change. To quote Carroll:

 Republicans are alone among major parties in Western democracies in denying the reality of climate change, a phenomenon that even puzzles many American conservatives. Denialism is growing among the rank and file, and the phenomenon is especially strong among those with college degrees. So it doesn’t seem to be a matter of lack of information, so much as active disinformation...

What makes American conservatives different from other right-wing parties around the world? Note that it wasn’t always this way — there was a time when Republicans wouldn’t have attacked science so openly. I have a theory: it’s Al Gore’s fault.

I too would be interested if there was such a backlash against climate change science if it did not become a political issue.   Or maybe it really has nothing to do with politics and the same people would oppose the science whether it was a political issue or not.

An interesting graphic from Wired related to this is shown on the right. It appears the more education conservatives have the less likely they are to accept human driven global warming.  This trend is opposite for independents and democrats.

Thoughts?

Do People Want Rational Arguements?

It's election season in the US and perhaps nowhere in the country is an election nastier and fueled by more money than the Colorado Senate race between incumbent Democrat Michael Bennett and challenger Ken Buck from the "Republican/Tea Party" ranks.  The polls show that the race is a toss-up - Rassumsen has it split 47% for Buck and 45% for Bennett - and money has been pouring into the state from the national parties at a ridiculous pace.  Last Tuesday, for example, over $3.6 million was spent in a single day according to a Politico.com report.  The TV and radio here in Colorado have been spitting out attack ads against both sides full of half-truths and out-of-context quotes almost non-stop.

Switching gears, the climate science community has been rocked recently by Dr. Judith Curry, head of the Department of Earth and Atmospheric Science at Georgia Tech and a respected researcher into things like Arctic ice and hurricanes, who has the audacity to engage so-called "climate skeptics" on their own turf - blogs like Climate Audit and Open Air - which some claim legitimizes them.  She has also publicly criticized the IPCC as suffering from groupthink and called for a reform in the way they present and analyze risk.  She sees herself as reaching out to climate skeptics for a more civil discourse, while some accuse her of propping up bad science.

I'm really not interested in discussing the politics of Colorado's Senate race or climate science here - that's not really our thing. What I would like to explore is the question of whether most people even want a rational argument. It often seems like most of the time it is more effective to call names or break off dialog rather than have a measured rational discussion.

I suppose the real question here is how do people react to things that are supported by reason or evidence that contradict what they think should be true?  Maybe it's really a contest between truth and truthiness.

The Colbert Report	Mon - Thurs 11:30pm / 10:30c
The Word - Truthiness
www.colbertnation.com
Colbert Report Full Episodes 2010 Election March to Keep Fear Alive

So what do you think?  Is there any rational discourse to be had or are we all thinking with our guts only?

NASA's Global Ice Viewer.

I'll spare everyone another research article today and will point you to NASA's Global Ice Viewer.  It's an interesting resource to see visually what has happened to ice levels on different parts of the world over time.  I discoverd this from Hanks's blog:

To get a handy view of what is happening in the big areas, Greenland, the Arctic and the Antarctic, NASA have put together a Global Ice Viewer.

You can zoom in on Ilulissat Glacier, which is is depositing icebergs in cubic kilometer denominations equivalent to 9.3 trillion gallons per year - if that sounds like 14 million Olympic-sized swimming pools every 365 days, it is. Or Antarctica, where ice shelves the size of small U.S. states have collapsed in recent years.

It's handy stuff if you want to show time-lapsed examples of change in the ice levels.

Enjoy! :) 

Innovative Solutions to Global Warming: Attack the Discovery Channel

Let me start out by saying that I am making light of something that was literally a life-or-death situtation for some people.  I'm not trying to be insensitive, just a little irreverent.  Speaking of irreverence...

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Almost all scientists who have studied global climate change agree that it either already is or is going to be a problem.  Even if you argue that a slightly warmer climate might be preferable to our current model, the fact is that we have based world civilization on the current climate and changing everything we've built over the last several centuries is going to be harder culturally, economically, and politically than leaving things be.  However some change is coming even if it's not in the climate - significantly lowering our carbon emissions is no walk in the park.  Basically what I'm trying to get at is that we could use some outside-the-box thinking in this area.

Thanks to mental problems, cable TV, and the availability of firearms in our country, we now have another idea:  stage a full-scale assault on the Discovery Channel.  From the Associated Press:

"A man who railed against the Discovery Channel's environmental programming for years burst into the company's headquarters with at least one explosive device strapped to his body Wednesday and took three people hostage at gunpoint..."

Apparently he felt that the Discovery channel was "encouraging the birth of... more parasitic human infants" and needed to be stopped.  I'm not sure I can explain a thought process that... um... unique in words so here's a pictorial representation:

therefore

 Whatever else you might call this guy, you certainly can't say he thinks inside the box.

Global Warming Could Be Bad... Or It Could Be Worse

The data on global climate chance from 1950 to the present leads to some pretty solid conclusions - the Earth's climate is warming and human greenhouse gas emission is at least one of the leading causes.  What everyone really wants to know, however, is not what has happened but what will happen to our climate if we keep doing what we're doing.  That's a much tougher question because it relies almost totally on computer models that use hundreds of parameterizations, simplifications, and approximations, some of which are poorly understood.  However the models aren't stupid - when one feeds in historical data one generally reproduces historical results - and climate scientists generally know what the uncertainty on each of these estimates are.

Based on these models the IPCC estimates that there will be a 1.8 to 4 degree Celsius rise in average global temperature by the year 2100, however with all the uncertainties some people might be inclined to say that there's a good chance it really won't be that bad.  They're right - turns out it might be worse.

From NASA's ever-useful Earth Observatory comes the results of running a suite of climate models thousands of times tweaking various parameters randomly (but in proportion to their uncertainty) on each run.  By doing this scientists get a feel for just how much what they don't know about their models can impact the results.  We call the result a probability distribution function, which shows the relative likelihood of the global average temperature increase by 2100.  Here's the result:

Clearly the highest probability is for an increase of between 1.8 and 4 degrees, as the IPCC claimed, but according to the models there is almost no chance of less than 1.8 degrees of warming while there is a decent chance of between 4 and 6 degrees of warming, and a slim chance of as much as 10 to 12 degrees of warming.

Global Warming Not Made Up By Rude Scientists

Many of you will remember the so-called "Climategate" and maybe even my thoughts on it. Yesterday the University of East Anglia's independent review panel released it's findings, which can essentially be summarized by the following sentence: "Global warning was not made-up by scientists with strong political views, gigantic egos, and poor taste in words."

More specifically, the review found that their was no scientific misconduct, no withholding of public data, and no vast conspiracy by the scientific illuminati bent on world domination. In fact aside for really bad manners, the only thing the scientists did wrong was not explaining one of their figures clearly enough. The review faults several researchers who produced the controversial "hockey stick graph" (shown below) for not clearly describing what one researcher described as a "trick" to synthesize temperature data from coral growth rates, tree rings, and actual thermometer measurements. After looking at the graph, you'll see why some might call it inadequately explained.Wait, nevermind. It's all perfectly clear to me now.

On a more serious note, "Climategate" has illustrated two important lessons for scientists. One is that being a jerk can come back to haunt you and your science even if you are right. The second is that openness and transparency are important, especially in potentially controversial fields like climate science.

How Much Will You Pay For Clean Energy?

We have all heard the term "clean energy" buzzing around recently. Climate science says that our current output of CO2 is dramatically changing our planet. President Obama wants to make it a major component of our future economy. Basically everyone seems to be in favor of energy sources that don't involve smokestacks.

That is until it comes to paying for it. A Rassmussen Reports poll released today shows that despite the preference for clean energy, when asked how much more they would be willing to pay for it 51% said nothing, while another 20% said no more than $8 per month. Only 24% said they would be willing to spend over $25 more a month to promote clean energy. That means over two-thirds of the country isn't willing to give up more than a couple of Big Macs per month for the environment.

So in typical American fashion, we want something but we don't want to pay for it.

Two MIT Scientist's Differing Views On Global Warming.

The Reference Frame brought my attenition to a story in The Boston Globe about two MIT scientists who were once friends and now at bitter odds over the global warming debate. I will post both their interviews below.

Don't Be Confused: I very much believe the data overwhelmingly supports the idea global warming is happening and very much influenced by humans.  However, for whatever reason there are still some prominent scientists who are not entirely convinced.  To be fair, I want to post responses by both sides.

Also, before one thinks this proves scientists disagree, just know the "nonbelievers" are so few in number that they are beginning to look like crackpots.

Feel free to debate this if you feel necessary.

Why you should worry:



Why you should not worry:

Severe Weather and Global Warming

I just thought I would add my own plots to Joe's.

Recently I came across NOAA's severe weather tracker, where they have the historical data broken down by month (and by day too, if you dig far enough) for severe weather events in the US. As a scientist my first thought was, "Cool! Data! I should plot that and see if I can see any trends." So I did.Looking at this data you should keep in mind a previous post of mine about interpreting graphs. So looking at this all I see is 2008 was a bad year, 2006 as well but 2009 was a relatively calm year. I would like to point out two things that I found interesting. The first has to do with the global warming political fight that is going on right now, the other deals with a more scientific question about the actual data.

Some where along the way certain elements in the news media found this data and were quick to point it out and say, "If there is supposed to be global warming, how come 2009 had the lowest level of severe weather we've seen in a long time?" To which the pro-global warming/environmental camp replied, "Weather is not climate!" But the problem is (and I say this at the risk of sounding childish, but it is true), they (the global warming/environmentalists) started it (as in, they were the first ones to confuse weather with climate). A few weeks ago I read a paper written (in 2004) by a couple of clear minded, rational environmentalists that were discussing the best tactic to take to push for environmental reform and legislation (I'll try and find the paper and post a link to it in a comment). While the paper was interesting I found the forward to be very interesting. The forward was written by the editor of the journal the paper was published in, and in the forward, the editor got on his soap box and said how the the environmental movement needs to emphasize more the connection between severe weather events and climate change. Essentially he was saying that the idea of slow climate change over 20-100 years was too far removed from people and that they needed to make it more real for people. Two years later in 2006 this idea of the connection between severe weather events and climate change was used extensively by Al Gore (in-)famous movie. The problem is, weather is not climate. For several years the environmental/global warming movement have been jumping on every case of severe weather and yelling "Look! Global Warming!" So it should come as no surprise when in 2009 the number of severe weather incidents dropped to their lowest level since NOAA began keeping accurate records (2000), the other side began yelling, "Look! No Global Warming!"

In my opinion they are both wrong. Weather is not climate, and the data we have is woefully insufficient. In terms of severe weather events we only have 10 years worth of (accurate) data, which is not enough to justify a comment about climate, which requires at least 20 years of observations. And the data is only for the US, not the world. Anyway, I guess I'll get off my soap box for now (for anyone who is interested I did find a well reasoned and sane article dealing with the climate change debate on Der Spiegel. This is probably the only news article you will find out there explaining the problems with the global warming political fight and where the debate went wrong).

So if you only look at the data by year there might be a few interesting observations you can draw, but things get more interesting if you look at the break down according to month.
Now that is an interesting pattern. It would appear that severe weather happens only in the summer and hardly ever in the winter. Which lead me to look closer at the data. It turns out that this particular data set contains only tornado reports, hail damage, and high wind damage, essentially it only contains "warm weather" severe weather. This is what you might call a biased sample. This data effectively hides "cold weather" severe weather, which also might be an indication of climate change, but again I should emphasize that we need AT LEAST 20 years of good data before we can begin to say anything about climate, right now we only have 10.

The other thing is where the data was taken. If you look at a map of where the events took place you may notice an interesting trend.
The severe weather happens mostly in the East. This may again be a consequence of the type of severe weather sampled (i.e. tornadoes, hail and wind), or it may be an indication of climate, which means if you look at it over a sufficiently long time (i.e. 100 years or so) you may see a trend. Again we only have 10 years worth of data. Or this could just be an indication of where people live. In the West there is more empty space with no people so it may just be that no one is there to report the severe weather. So many uncertainties! (uncertainties that you will never hear reported in a news story).

NASA: Hottest Jan.-Apr. On Record. (Useful Plots)

Thought people could use some useful plots from NASA.   One thing this data is supposed to show is that Jan-Apr is the hottest on record.

 You can debate what they mean for yourselves.  Enjoy. :)

Physics Works: Global Warming Edition

When people talk about human influences on the global climate, they tend to think that there is much less certainty in the conclusions than actually exists. In fact while the models have a lot of approximations and simplifications, they really do an excellent job simulating the global climate history. You want proof? Behold NASA's really pretty graph (click for a larger version or click here to read the full article):
The dashed line is recorded average global temperature anomaly, which are uncertain to maybe 0.3 degrees C but become particularly reliable after about 1970 when space-based measurements became available. The red line is the average of several global climate models including human influences and the blue line is the average of those same models without human influences. You'll note that almost all of the observed warming does not occur in the models without human influence. All I have to say is WA-BAM! Physics Works!

One other interesting thing to note: the two largest natural influences on climate are volcanoes (labeled and with vertical grey lines) and the El Nino cycle. So it's not that the climate isn't strongly influenced by natural events, it's just that these events don't tend to produce a consistent heating or cooling effect. Humanity, on the other hand, is consistently heating the planet and shows no signs of stopping.

The Wall Street Journal Asks "Where's the CO2?"

Have you ever wondered where all that CO2 humanity is pumping out year after year is coming from? Well leave it to the folks at the Wall Street Journal to come up with a lovely interactive graphic that shows exactly where the CO2 comes from. Unfortunately the WSJ hasn't discovered the miracle of embedding applets yet, so you can check it out here.

A few interesting tidbits:

1. The ratio of CO2 output to worldwide GDP has actually dropped by a third in the last 40 years, meaning that it is absolutely possible to grow the economy without pumping out more CO2.
2. The #1 anthropogenic source of CO2 is - you guessed it - coal. The WSJ does not, however, include things like CO2 from deforestation, which may be an even bigger net effect since you have both the loss of a carbon sink and a carbon source.
3. The fastest growing source of energy in the last decade is - you guessed it again - coal. Unfortunately it's cheap, easy, and dirty.

Our Bizarre Climate: Global Versus Local Warming.

I'm sure you've heard that the east coast of the US is getting record snowfall and many people are claiming this seems like the coldest winter in a long time.

However,  "Globally, last month was the warmest January ever as measured by RSS's satellite, and and the 4th warmest month in their records -- the warmest since May 1998."

Maybe February will come out different.  However, as things stand we are witnessing some bizarre realities about the climate: even though globally we are experiencing warmest temperatures on record, locally we are getting snowed in.

Now we know why it is called global warming as opposed to local warming.

Update:

Stan pointed out how the Daily Show had a pretty convincing graph that disproves the idea the earth is warming.  This is from a large data-set taken over several months so it should really carry some weight in the global warming debate:

Thoughts on “Climategate” from a Computational Scientist

If there is a more controversial topic in science than climate change I don’t know what it is. Even then most of the controversy isn’t really about the science - it’s about the politics, economics, and ideology related to the science. I have previously posted on how people’s opinions about climate change are influenced by non-scientific factors. For those of you that follow the news, you have heard a lot about the recent controversy over copies of stolen e-mails from the University of East Anglia, Britain’s main climate research center. These e-mails contain unprofessional comments about climate change skeptics, comments about data analysis “tricks”, and even a couple remarks about denying, delaying, or deleting public data requests. For a good summary of the whole mess, see this story from the New York times.

Dubbed “climategate” by conservatives, many have pointed to these e-mails as evidence that the science behind climate change is false. One writer has gone so far as to say that this is “the final nail in the coffin for global warming”. I am not a climate scientist, but I do work with climate scientists and I do work on large computer simulations of the sun which are somewhat analogous to the global climate models (GCM’s) upon which many future predictions about climate change are based. So here are my thoughts on this whole mess.

1. Nothing that I have seen in these e-mails suggests that the science behind global warming has been faked. Anybody who has ever taken a math class has learned “tricks” for working problems. Computational science is full of simplified approximations that make these simulations possible. There are a lot of simplified approximations in climate science, but the overall consensus between many different models using many different approximations is that humanity is driving up atmospheric concentrations of CO2, which it turn warms the planet. Currently all of the major computational models agree that observed warming trends are largely due to anthropogenic forcing, so while one model would be questionable, the fact that all of them agree on this point is a pretty good indication that they’ve got it right.
2. Most people have no idea how science is done. Science classes are filled with tidy little experiments that produce tidy little results that are always consistent with other experiments and never unexpected. Real science is full of ambiguous individual results that on their own lead to uncertain conclusions. But when real scientists see strong statistical trends in data over many different models and experiments, they can confidently draw correct conclusions. The general public (and many with political agendas) are often uncomfortable with the idea that unresolved details can be a part of a well-supported theory, so they either discard the unresolved details or the well-supported theory.
3. Like many people, some scientists have big egos and lack social skills. On top of that, scientists have spent years learning the intricacies of their specific research topic. Add to that the fact that a large portion of the general public - including many politicians - are essentially scientifically illiterate and some scientists can at times feel justified in draconian measures like repressing dissension or limiting access to data to get the general public to agree with scientific facts. It’s not right, but at the same time I think think it comes more from frustration than some sort of politically motivated conspiracy.
4. One thing that no one in science will stand for is bad science. If climate change could be disproved through rigorous scientific tests it would be the sort of result that would make the person that accomplished it an instant celebrity in the climate community. To borrow an example from astronomy, in the late 1990’s two independent teams of highly qualified astronomers released independent data showing that the expansion of the universe was accelerating. This destroyed 40 years of work in cosmology that assumed a decelerating universe - in some cases entire careers’ worth of work was rendered invalid overnight. There were a lot of skeptics, but the data was solid and the two teams measurements were independent. When the results were announced at a meeting of the American Astronomical Society they were met with a standing ovation. The point is the scientists as a whole are interested in the truth even if its not on their side of the argument. If there were conclusive evidence showing the global climate was not changing climatologists would embrace it. The reason most of them fight skeptics as hard as they do is that the data disproving climate change simply isn’t there. Instead all sorts of tests indicate that the climate is changing due to human activity.

So there are my thoughts. The e-mails don't disprove the science behind climate change, but they do lay bare some of the short-comings of both the general public and the scientific community.

The Recession Changes Minds on Global Warming

In the past decade the science behind global warming has gone from solid to all but certain. Human activity has been shown to better than 90% confidence to be the leading cause of global climate change by the Intergovernmental Panel on Climate Change (IPCC). The IPCC is essentially a who's who list of atmospheric scientists, climatologists, and economists that specialize in climate related issues. They are experts and they know their stuff.

In April 2008, back when housing prices were a concern and the economy was just starting to slow down, 47% of Americans believed the IPCC while only 34% didn't. But then the recession hit and things changed, at least in the minds of the average American as measured by Rasmussen polls.
Each poll in this series has an error of +/- 3%, but it appears clear that over the last 18 months or so there has been a clear trend towards blaming "planetary trends" for global warming instead of human activity. The science on global warming hasn't changed in the past year, but it appears that economic worries trump science in the public mind when they think about global climate change.

If you think the weather where you live is bad...

I saw this on my google homepage this morning it was too good to pass up.Talk about extreme fluctuations in temperature! (Hint: the current temperature)

It's Too Late, I Already Doomed the Earth

A few days ago I received an Amish Friendship bread starter. For those of you who don't know it is just a basic sourdough culture that you grow and feed for 10 days and then you make bread out of it. The catch is that the instructions instruct you to separate out 4 cups of starter material before you make the bread and put each cup in a bag and pass it along to some friends (hence how I got it). So there we have the problem and ultimately the doom of not just the US but the whole earth!

According to the instructions the starter will grow in volume by a factor of 4 every 10 days. Thus the increase in the volume of the starter can be expressed as 4^n where n is the number of 10 day periods between bread makings. Given this unchecked growth this starter which started out as l cup of material (roughly 236.6 ml) will grow and grow until it has consumed the whole earth! To give you a timescale to see what could happen, let us consider 1 year. 1 year has about 36 10 day periods which means by the end of one year we will have 4^36 cups of material. After a brief calculation we find that this equals roughly 1.12 BILLION CUBIC KILOMETERS of material!!!!!!!! This is enough to cover the whole earth with ~1.5 MILES of sourdough starter! And that is just the starter! (not counting the bread made from it) all in less than a year!

So yesterday I passed out the starters which means I have roughly 100 days before I am buried by it. I estimate that it will hit Illinois and Texas sometime by the end of this year, Colorado shortly after that and California a short time after that. Plan accordingly.

On a serious side note, something like this can be used to show the holes in the logic behind a lot of sensationalism about global warming. It seems that most (all) of the dire predictions about global warming assume unrestricted growth or extreme extrapolation with no consideration for limiting factors, negative feedback, or even other (non-negative) possible outcomes. Sort of like several of the end of the world (US) predictions mentioned on the site Nick told us about. One scenario had the Great Plains turning into a vast desert. While desertification my be a problem to some extent, this is a prime example of what happens when we take a "what if..." scenario too far. The scenario is only possible if we completely disregard how climate actually works.

Solar Cycles and Global Climate

Ryan previously made reference to an idea I get asked about a lot, so I thought I'd leave a quick post with my two cents on the matter. While I am a solar physicist, I do not work on issues of solar irradiance or even solar changes to space weather, so I am not an expert in this exact field. However, I do work on dynamo models that explore the sun's magnetic behavior over hundreds of year. Basically, I am not the best person to ask about this, but I'm familiar with what is going on in the field.

So here's the question: is the sun causing global warming? And here's the quick answer: no, at least not in the past 50 years. Here's a more detailed response:

The sun's magnetic activity does appear to impact the Earth's climate. Historical records indicate that a lull in solar activity called the Maunder minimum corresponded to a very cold period (especially in Europe) from 1645 to 1715 AD. The exact mechanism linking solar activity and climate is not well understood because the variations in total solar luminosity are extremely small (less than 0.1%), which rules out direct effects. However, there are several indirect effects that may drive climate changes including modifications to upper-atmospheric chemistry and increased cosmic ray fluxes changing cloud formation reates. Whatever the mechanism, the sun appears to drive changes of about +/- 0.5 degrees C. But that cannot account for the rapid change in temperatures in the last 50 years. And here's a figure that shows it:
This figure, compiled by the good people at NASA-Marshall's Solar Physics Group shows some correlation between solar activity and temperature, but the large spike in temperature since 1950 does not have a corresponding increase in solar activity. So while the sun might cause something on the order to a 0.5 degree change in global average temperature, it does not explain the current warming trend. Atmospheric CO2 concentration does a far better job matching the warming trend. So while the sun is a player in our climate, it is not the dominate agent of change right now.

As a side note, these solar forcing effects are just one more set of parameters that get fed into climate models, providing more poorly constrained parameters to fiddle with.

My Response to Joe

I was going to write a comment in response to Joe's response to me but like Nick's response to my post my comment became to long so I decided to make it another post.

First, I disagree with the assertion that Nuclear energy and associated technology can't be exported. We can, do and will export nuclear technology. We have been exporting the technology for years to places like India and Brazil. Brazil even changed their constitution to allow for the construction of nuclear power plants a few years ago (about the same time Iran was doing the same thing. We all know about Iran but how many people know about Brazil getting nuclear power? There is a reason for that.). So if it comes to exporting technology, which ever one we go with will be the one we export.

I agree with Joe in that we need renewable sources of energy, but sometimes we need to use the non-renewable sources so that we can make the renewable sources.

I think the environmental impact of using fossil fuels will actually be less than the politicians make it out to be, and it may be possible that it will be beneficial to the planet (if they are allowed to make a worst-case scenario prediction I think I am allowed to make a best case scenario prediction and the truth will be somewhere in between).

I think that in the global climate change issue (and the related fossil fuel issue) there are two main problems. The first is the human cost. Fossil fuels have been cheep, plentiful, useful and relatively easy to use. The energy density of fossil fuels is phenomenal (though nowhere near that of nuclear fuel), and that is why they are so useful. They are also a very convenient form of energy to transport and to carry. But the problem with them actually has nothing to do with the fuel itself but rather the immense political and human cost of having the fuel. Like Nick pointed out with Iraq, that is the true cost of oil, and it is a cost that is too high. If oil was available without associated wars, contention and bloodshed, I would not object to using it so much. Nuclear power does not come with these political or human problems.

The second problem is the political cost of implementing the new "green" policies. The current push to "Go Green" is too much, too soon and at the wrong time. If it had been any other point in time our government, economy and society could have handled it, but right now the cost of pushing "green technologies" may be too great. If this economic recession starts hurting more and more people and the find out that they have to pay for developing green technology and to pay for being "green" on top of everything that is happening, then there will be a backlash and it will severely damage any prospect of building an infrastructure of renewable energy. Thus I think that the nuclear option is the best option at the moment.