With fierce storm after storm hitting the Caribbean and threatening our coasts this hurricane season seems to illuminate the ever more apparent effects of climate change. While we do not have more storms than usual the intensity appears to be on the rise, i.e. more storms are reaching higher categories thus our extremes are getting more extreme [Science]. This alone calls for our attention and efforts to make changes to decrease the greenhouse effect that is warming the Earth and causing greater highs and lows but there is more to this than meets the eye.
It is clearly necessary to work to decrease emissions that are contributing to climate change but what we may unknowingly be doing is exacerbating the problem by not fully understanding the complexity of the system. Now I am not saying we should allow massive amounts of pollution, I am merely suggesting it is more complicated than the simplified version we get watching TV or the glossy greenwashed sound bytes we are so often exposed to. Even this write up is overly simplified but such is life. The main complication I speak of is the phenomena that is termed “global dimming.” Just like it sounds, global dimming describes the decrease in sunlight that is actually reaching Earth’s surface.
Over the past 4 decades scientists have watched the global incoming solar radiation decrease by 12% [American Geophysical Union]. TWELVE PERCENT. That is huge! Breaking it down for each continent the drops in sunlight recorded between the 1950s and 1990s are staggering. The level dropped 9% in Antarctica, 10% over the U.S., nearly 30% 13% over Russia, and up to 60% 16% in parts of England (thanks for pointing out this misunderstanding). With that you would expect that we should be cooling down, right? It is logical to think if less sunlight reaches Earth the temperature would drop, just think of a cloudy day or even just standing in the shade. It makes a significant difference but we are not cooling down, we continue to get warmer.
With this in mind it may be that global dimming is masking or delaying the potentially far more extreme effects of global warming. Particle pollution, like ash, soot, and sulfur dioxide, in the atmosphere is believed to be the culprit for global dimming. Just like sunlight bounces off the top of clouds, so too will it bounce off of polluting particles. The compounding factor though, is that the polluting particles apparently make the clouds themselves far more reflective.
If we were to eliminate global dimming all together without addressing global warming the increase in temperature and extreme weather might be more significant than previously predicted. This has been recorded with one full degree temperature change in just a few days of decreased pollution in the days following the 9/11 attacks [Nature]. This reverse effect of dimming has been has been blamed along with global warming for increasing temperatures, appropriately called global brightening [Geophysical Research Letters]. No one wants smoggy skies but it could be smog and particulates that may be shielding us from the full consequences of the greenhouse gases we pump into our air daily. Clear blue skies are something many folks thinks of when they think of “going green” but those clear blue skies may hold more heat than we can handle.
BBC Special on Global Dimming on YouTube: Part 1 | Part 2 | Part 3 | Part 4
Related posts:
Tracy Perkins | Posted in 
Subscribe to Feed
September 9th, 2008 at 7:55 pm
Not to mention, decreased sunlight = decreased flora = decreased oxygen and food and the ability to capture carbon.
September 9th, 2008 at 11:08 pm
Thanks for the interesting post, and the relevant links. A book that has been circulating for a few years now is
‘Nearest Star’ by Golub and Pasachoff. If you like details of diagnostics as well some clear explanations of experimental observations regarding the role of solar cycles on the earth’s climate it is a good read. It is a few years old now, but hardware has not been updated (pretty sure, but correct me if wrong) so you can still learn a lot about “state of the art” physics research on the topic of solar radiation intensity that is discussed in this post.
September 10th, 2008 at 5:13 am
I’ve said it before and I’ll say it again..anybody who thinks that global warming is a socialist plot to destroy our government hasn’t been looking around their favorite wild areas too closely.
September 10th, 2008 at 10:53 am
Wow dude that is pretty cool.
Jiff
http://www.anonymize.us.tc
September 10th, 2008 at 11:10 am
[...] Developing story, click here… This entry was posted on Wednesday, September 10th, 2008 at 3:54 pm and is filed under le Chat Marchet. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site. [...]
September 10th, 2008 at 11:11 am
Oh, for christ’s sake.
Did anyone notice that we used to put out a lot more particulate matter than we do now, basically from the beginning of the industrial revolution until the 1950s, when we mostly transitioned from coal-fired steam to electric power for industry?
Now that the earth hasn’t warmed up AT ALL for the last decade, the global warming crowd is looking for excuses, and lo and behold, they find something that’s even more dire and alarming.
Sorry, but I’m old enough to remember the dire warnings of an impending ice age back in the 1970s.
September 10th, 2008 at 11:42 am
See, I am not old enough to remember things from the 70’s since around that time, my father was my age.
However, I do read and what I have read is about terrorist attacks on the World Trade Center that just harmed it, not totally destroying it and people just brushed it off.
I have also heard about gas crises of the 70’s where people were lined up around blocks to “fill-up”
I have heard about polar bears drowning because they were not able to rest on pieces of ice (which melted) in the arctic ocean.
…I also remember Y2K.
My point being we (Americans) tend to only react once things turn into catastrophes instead of preventing that catastrophe from happening in the first place. Even if global warming doesn’t exist (which I think it most certainly does) what is wrong with making the environment a better place? What is wrong with not having to depend on paper and instead using environmentally safe materials that are man made. What is wrong with not using oil anymore? Would it not be nice to put water in your car? It would save you money.
Sounds like a nice place to me, what about you?
September 10th, 2008 at 11:47 am
To SomeGuy
Um, you did notice the vanishing icecaps? The fact that for the first time since, like, ever, in recorded history, we have an ice free north pole? Stop pretending to be an ostrich, this is real!
September 10th, 2008 at 12:16 pm
Um, slight problem with this article. “More particles in polluted clouds prevent moisture from condensing as rain.”
Remember your basic elementary school science classes here people. For the water to condense at all, it requires a pollutant (typically dust) to cling to. After that, it attracts more and more condensation until it becomes too heavy to remain airborne, and falls as rain.
The very concept of seeding clouds in order to make it rain is to dump particulate into the clouds to give the moisture something to condense around.
More particulate in the clouds would increase rainfall, not decrease it.
September 10th, 2008 at 12:20 pm
And that proves what exactly? We have accurate records for the last five decades; the rest is guesswork. There is ample evidence for those that have even half a brain that so called global warming has happened many times before. Long before mankind was around.
September 10th, 2008 at 12:22 pm
Sorry Chris. My comments were directed towards Jake.
September 10th, 2008 at 12:32 pm
Chris,
Thanks for the comment, I will clarify.
You are right that rain needs particulates to condense on. The problem is that with so many particulates they cannot get as heavy – more particulates with less water on each one makes for many light weight drops that are less likely to fall as rain. I see where you were coming from and hope that is clarified.
September 10th, 2008 at 1:30 pm
Here are some true stories. When I was five and my brother Fred was seven in 1965, we and our sister Marji would look at over the ocean and determine whose eyes most closely matched the sky. That would be very very blue.
In 1966, when I was in first grade, I and two friends were lying in the grass watching the cloud formations and my buddy Greg Ponder made a comment that the sky that day EXACTLY matched the blue crayon in the crayon box. We pulled out the crayon and he was correct, it matched exactly.
When you see old western movies filmed in Cinerama and coda chrome, many filmed in Sedona, the deep blue of the sky was the true color of the skies in the 1950s and early 1960s and in fact was so deep blue that they had to use a polarizer and contrast editor to lighten the sky.
In 1977, as the skies were beginning to fade in many areas, Hawaii was still pristine. While sitting on a surf board next to my friend Larry Klair, I commented on how bizarre that the sky was the exact same color of the water on that particular day. The sky used to be so DEEP blue that much literature, songs and poems were written about it, and I swear until I was five or six, you used to be able to see planets and stars during the daytime because the atmosphere was so clear. You can find others mentioning this online.
In fact, Venus used to be called the “morning star” and the “evening star” because at both of those times during daylight you could clearly see it, sometimes it looked like a golf ball just sitting up there during the daytime. That is how dark blue the sky used to be.
I’m afraid we will never see those days again but it was one of nature’s most spectacular gifts. Not only did the color of the sky change, but so did the colors of the terra which were vivid and not hazy.
September 10th, 2008 at 1:41 pm
To BoredOutOfMySkull,
Of course global warming has happened before. There are many times when vulcanism has rapidly raised the level of particulates in the atmosphere, as have the occasional meteor impact. And yes, life will survive, probably even us. Does that mean we really want to change the planet by wiping out the only water sources from the himalaya mountains, increase the strength of hurricanes, and changing numerous other ecosystems? Probably not. But the point was that stating that the temperature in your own back yard not changing is proof that global warming is wrong, is foolish.
September 10th, 2008 at 1:49 pm
Ugh, I just mixed up dimming with warming. But the point still remains. While direct evidence has only been recorded for under a century, indirect evidence via any number of sources abound, showing arctic and antarctic ice having existed for centuries. I remember reading about core samples from Antarctica dating back millenia.
September 10th, 2008 at 2:03 pm
Tracy,
The ‘too many particulate’ theory defies the very nature of particulate collection of water. a drop of rain does not have a single seed. it usually has multiple seeds that join and cling together before falling as rain. The more fine non-water matter in the clouds will generally make rain happen at an accelerated rate rather than a decelerated rate. The cloud would drop the excess contents at a higher dew point than normal in addition to dropping rain in areas that would not normally receive as much. This may cause a cloud to be rained out by the time a less particulate laden cloud would have reached a certain destination.
With finite particles that are hydro- and egophilic, it only makes sense. The clouds would otherwise be bubbles (if it were hydrophobic particles) or disperse due to the vapor and particulate that is “light weight” and would also be less likely to hold together.
If the theory of lighter raindrops not falling and staying in the atmosphere longer is correct, then lets look at cloud cover and cloud formation density over the past 50 years as well. (Remember to take into account the solar cycle’s impact on cloud cover as addressed by Balling and Cerveny).
I would love to go on but I’m not the one that gets paid to write for this page.
September 10th, 2008 at 4:33 pm
Please refer to http://www.bariumblues.com for the inside truth about particulates caused by aeresol spraying aka chemtrails.
September 10th, 2008 at 6:28 pm
Ever hear of inertia? A heat sink? Have you noticed that when you heat up a frying pan you can still burn yourself several minutes after it is taken off the stove?
It could take several years, if not decades for the earth to cool after solar radiation decreases due to the mass of the earth and the stored heat. We are starting to see the decrease in temperatures now from decreases in radiation several years ago.
September 10th, 2008 at 6:33 pm
What makes you think that today’s climate is “normal”?
Geologic history tells us that this is not a normal climate and that the earth has had many periods without ice caps. Long before man was around.
And why do all the rising temperature charts we see start at the end of the “Little Ice Age” when the temperature was unusually low?
Artistic license?
wjd
September 10th, 2008 at 11:15 pm
Great documentary, although there are a couple of inaccuracies in the article.
First, the 60% dimming in parts of England has been misheard. The documentary actually quotes 16%, in line with other rates of dimming around the world.
Secondly, the issue that was taken up Chris – “More particles in polluted clouds prevent moisture from condensing as rain” – is a misunderstanding of the documentary by the author of this article.
What the documentary describes is the negative effect that the dimming has on the process of evaporation. With less sunlight reaching earth, less water evaporates and therefore there is less rain.
A good documentary, well worth 40 minutes of anyone’s time. It would appear that we are in a real Catch-22 situation here.
September 11th, 2008 at 4:28 am
I already understood this, but it’s pointless to bring up details to the apologists for Big Pollution in this country, because really we are talking about changing the “free market” lifestyle, and any details sound like excuses.
I have only one thing to say;
“Sorry, if our explanations of climate science are too complex to fit on your bumper sticker.”
– signed, the Scientists who understand these sorts of things.
September 11th, 2008 at 6:44 am
Thanks for all of your comments! I’m glad people care enough to leave a note, whether positive, negative, or clarifying. Thanks, Dickie, for pointing out the misheard percentages, it has been corrected.
September 11th, 2008 at 9:11 am
To Some Guy:
No, you *don’t* remember any such thing as scientists clamoring about global cooling in the 1970’s. Mainly because there were no such scientists.
What happened in the 70’s was the discovery that Milankovich cycles (nutation of Earth’s axial tilt) appeared to correlate with the last several ice ages. There were some data that *might* indicate Earth was cooling and that we were heading into another cooling cycle according according to the model. Several scientists testified to congress that this *might* be a problem but there was simply not enough known and they really, really, needed more funding to figure it all out. OH, and the reason they said *at* *the* *time* that it may not be a problem? All that CO2 we were spewing would cause *warming* that most likely would swamp any possible cooling.
What you are remembering is right-wing-nut screeds from the past five years or so claiming there was a clamor in the 1970’s of global cooling.
And even if there *were* clamors about cooling, you don’t think climate science has advanced any in the past 30+ years?! If not, go look up “radiative transfer” and “integro-differential equations” and consider the advances simply in computer power over, say, the last year or two, let alone 30.
September 12th, 2008 at 5:52 am
To drklassen:
Let’s not give ‘right-wing-nut screeds from the past five years’ all the credit for global cooling claims of the ’70s. While science may not have validated the idea, pop culture (i.e. Newsweek) promoted it. So you can blame some of the pop media as well for making so many people skeptical this time around.
peace.
January 24th, 2009 at 3:54 pm
This was helpful & this is REAL people. It’s NOT a joke. Would u like 2 die now(this very minute)? I just hope & pray that everyone will survive(including Jeff Hardy)
March 18th, 2009 at 8:23 am
Great videos on YouTube. Very interesting. You should better watch guys.
March 23rd, 2009 at 7:43 am
Dont ask what mother nature can do for you. Ask yourself what you can do for mother nature.
March 30th, 2009 at 4:56 am
good explanation. thx for this interesting topic.
November 18th, 2009 at 7:08 am
Great Post about nature. Very interesting!
December 18th, 2009 at 1:42 am
[...] Blue skies, scorched Earth? What is Global Dimming? [...]