Ok, so let’s say you agree with the scientific community and accept that global warming is occurring and is due to anthropogenic (man-made) greenhouse gases. But you might wonder why everyone is so worried about what ultimately amounts to only a few degrees difference. Even the IPCC’s worst-case scenario—rapid global economic growth characterized by intensive use of fossil fuels—leads to rise of global average temperature by only 7 degrees Fahrenheit. Individually a bit uncomfortable, but not a big deal, right? By the way, the IPCC uses Celsius, but I use Fahrenheit, because whatever, I’m American.
Let’s say that instead of rushing headlong off a cliff, the world governments decide that the best course of action would be to save the world, so greenhouse gas emissions are reduced in a best-case scenario... we’d still be looking at between 2 and 4 degrees Fahrenheit change over the next 100 years (if all emissions were to completely cease, the temperature would still rise by about a degree or 2). What would a 1-degree change matter? After all, summer in Boston wouldn’t be much more unbearable at 101 degrees than at 100.
Well, a 1 degree rise leads to a number of gradual changes, including the thermal expansion of water, increased precipitation, acidification of the ocean, and others... but here’s one concrete reason why it matters: a global average change of 1 degree might mean that Boston has a slightly more murderous summer, but more importantly, somewhere in the world, the temperature would rise from, say, 31.5 degrees to 32.5 degrees. And suddenly you have a real problem. The freezing point of water is a threshold temperature in that polar regions could warm 5 degrees and not make a significant difference, but as soon as that boundary is reached, ice starts to melt. And melting ice means more melting ice. The albedo effect refers to sunlight being reflected by ice; the more ice there is, the more light is reflected from the surface, and that cools the earth. This feedback effect works both ways: when ice melts, there’s less ice to reflect sunlight, so warming accelerates, and more ice melts.
A global rise of 1 degree on average actually means a several degree rise in the Arctic, as the Arctic is expected to be most affected by warming. This is due to the climate system. Essentially, the climate is the redistribution of heat around the globe. In Chief Scientist Jim Swift’s own words, “The sun shines, solar energy is taken in more strongly at the equatorial regions, and radiated more strongly in the polar region. And the climate is how the earth solves that puzzle of redistributing heat. Not as opposed to weather—the local manifestation—the climate is the overall big process.”
An example of this heat distribution process is the Gulf Stream, which carries tropical water up and across the Atlantic, where it cools off in the high northern latitudes. By “cooling off” I mean that it dumps a tremendous amount of heat into the Arctic region. There are similar currents and winds all around the world that generally pull heat away from the tropics up to the poles. Well, what some scientists are looking into is whether the “climate puzzle” has multiple solutions. Sophisticated climate models point to multiple solutions that get heat from the equator to the poles, but switching from one circulation pattern to another may be like a step function. Once a stable system is upset enough, it may suddenly and irreversibly shift (“suddenly” in geological time, of course). One fear—still considered “behind-the-scenes” as it is not yet verified—is that we may be headed toward one such point of no return. If changes are gradual, people can gradually adapt. But if a change took place in 10 years that was expected to take place over 1000 years, it could be disastrous. But are we accelerating such a process, or reversing it, or changing it in an unknown way? We just don’t know yet. It’s been said before, but we are undertaking the greatest experiment ever, and we don’t know what we’re doing.
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By the way, The Host is out. It’s a Korean monster film. I was in Seoul at the time of its production, and thanks to a wildly cool family connection I was able to visit the set—a dank sewer under the overpass—when they shot one of the monster sequences. It’s always fun being behind the scenes: the star, Bae Doo-na, was relaxing and drinking coffee while her stunt double repeatedly ran from the camera, spun around, got whacked by a guy in a monster costume, and then got yanked back by an awesome wire contraption. They did that shot like ten times over. I hope that shot made the film... I feel bad for the stunt double. Can’t wait to see the movie! And, curiously enough, NY Times Reviewer Manohla Darghis likens it to An Inconvenient Truth.
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Name: Daniel Park
Alias: Dan
Occupation: Media Specialist on the R/V Roger Revelle
Destination: Antarctica
Mission: To document the efforts of climate change researchers and to bring joy to the loneliest place on earth...
4 comments:
Hi Dan,
We are an 8th grade class in San Marcos, Ca, Our cups were just "squished along with yours"..We are anxiously awaiting their return! We have been reading your blogs and watching the ship on the live webcams.
We have been studying the effects of Global warming as part of our science class and thats why we have been watching Dr. Swift's cruise.
We watched Al Gore's Inconvenient Truth and discussed the implications. We were concerned with an article that came out last week: Climate Reports Sounds Dire Warning!
http://www.msnbc.msn.com/id/17554963/
We have been studying the "Oceanic Conveyor Belt" and from what we have read there is some disagreement between scientists about how quickly global warming will effect it, but most scientists do agree that it will be effected. We are interested in seeing any changes in the data Dr. Swift collects on this cruise compared with the last time the data was collected.
If the Global Ocean Conveyor Belt were changed ( slows down or perhaps something like the Gulf Stream, changes course) what would be the effects we would feel. We wonder what the result would be if the cold deep water off Greenland didn't sink anymore? Would this effect heat transport ( yes, we are pretty sure from what we have read that it will!) Well there would be no more strawberries in Norway, Polar Bears would be in for a bad time ( relegated to zoos....) But we here in warm sunny San Diego might have to not only do Emergency Drills for Earth Quakes, we might have to practice our hurricane drills too!! If our coastal waters warmed even 5' C we could see drastic changes in our plant and animal life....Mrs. Brice says, Think: El Nino all the time ( she says thats a little simplified but...its a visual). When we have an El Nino here 80-90% of our seals and sea lions die, our kelpbeds die off and we have flooding problems. Our entire ecosystem are dependent on that cool ocean current along our coast...what would we do without it? After watching the movie we had to go out and see what our school and our community were doing to help slow Global Warming ( note: we said SLOW, not STOP....our research indicates few if any scientists think we can stop this now that it has begun) and we found that at our school we don't even recycle paper and aluminum cans.... we took a poll of how many student's parents drive Hybrids: less than 5%
Of course that led to a big argument on how efficient these hybrids really are ( new studies are showing they are not nearly as efficient as they told us....and we want to know what happened to those all electric vehicles....???)
We would like to know how you and the scientists and crew aboard the Revelle feel about efforts to slow Global Warming? Have the crew seen changes in climate patterns over the past 10 years while sailing on their science cruises? Has your opinion of Global warming changed since going on this cruise? Will it change your behavior or habits?
Thanks
Mrs. Brice's Classes ( Pirates in training!)or oceanographers....
Chief Scientist Jim Swift's Response:
Hello,
I’m happy to provide a few responses. These are top-of-the-head, not referenced, rambling and overly-long, etc. - just what occurs to me on this rather windy subtropical evening.
The "Global Ocean Conveyor Belt" is less a single, tightly-connected belt-like 3-D circulation than it is a convenient and popular term for a global scale assembly of ocean processes that plays a role in the largest scale of moving heat and fresh water. "Climate" is, in one perspective, the largest scale result we readily perceive in space and time of how heat and fresh water are distributed and balanced globally. A way to think of the "Global Ocean Conveyor Belt" may be that it is how the large-scale ocean circulation fits together between the oceans, including the vertical parts as well as the horizontal parts of the circulation. In the present day, we associate certain currents, outflows, sinking and upwelling areas with this term, and at their present rates. But there are conceivably different pathways or rates for these, at least to a degree that is physically plausible. (You can't have a Gulf Stream-like current feature just any old place.) One problem in studying variations in the components of the "Global Ocean Conveyor Belt" is that so little is known about their natural variability, their interdependence, and sensitivity to change, plus the time scales involved in meaningful change might be rather long in terms of how long we have been measuring them well enough.
So, for example, is the flow of warm, salty water from the Gulf Stream / North Atlantic Current system into the Nordic Seas (the region of ocean between Greenland and Norway) driven by the need to replace the dense waters coming out over the sills between Greenland and Scotland into the deep North Atlantic, or is it more nearly part of the wind-driven surface circulation? The answer is probably "yes" :) i.e. a little of each. But assume you have measurements that indicate less deep water is being formed in winter from the sea surface in the Nordic Seas, and you also have measurements of some of the dense outflows suggesting the outflow has reduced in volume ... does this directly mean that less warm, salty water will be flowing north near the coasts of the UK and Norway? Or is that warm, salty flow more nearly regulated by the large-scale winds, which, maybe (or maybe not?) haven't changed all that much? If you lived in Norway you'd like to know. So we try to devise tests (experiments, data collection, models, etc.) that will peck away at the pieces of this problem. And that's just one little area of ocean climate research!
RE: "the "Oceanic Conveyor Belt" and from what we have read there is some disagreement between scientists about how quickly global warming will effect it". See, it's a more of a muddle than a conflict.
Well, pirates/class, there is quite a bit in your statements, isn't there? I'm heartened to learn of your interests and concerns. Science today is so specialized that most individual scientist's work can focus on only a few pieces of the largest problems, such as how we may be affecting our planet and what we can do to avert the worst of any irreversible changes. Certainly the concept of "think globally, act locally" applies to our interactions with ecosystems and the climate system. It may not be politically correct to say what I will say next, and this is a personal (not scientific) statement, but to my present understanding it is true (and if it is not true I will recant it): If you lived in a poor village in some far-away land, would you like to live as we do? If each of the planet's citizens used same amount of energy daily that underlies the lives of each of us in the USA (not just the energy we use directly at home, but our part of the sum of all the energy that goes into making what we use), and even if that energy were made via an extremely efficient process that did not involve CO2, all of it eventually gets turned into heat, so the sum over the whole planet of everyone living as we do would warm the planet, CO2 or not CO2. Either (1) there are too many human beings, (2) we need to hugely change our lifestyle (in ways that may be very harsh indeed), or (3) we have to maintain a social structure of energy-users and energy-poor. Or something like that. ?? So, if you ask me how I am affected by what I see in the data, I don't know how to answer that. I think my role is to make the very best measurements I can, in regions I and some learned colleagues feel would be most useful, so that those who are trying to better understand the ocean's role in climate variability can do a better job of it, and, through the process of science advising, provide the best judgement to people and nations to help decide what actions may be necessary to protect the overall best interests of mankind.
Take an example from another area, one I know a bit (but not much) about. We have observed that the Arctic Ocean ice cover is thinning and seasonally retreating, especially in the areas north of Alaska and far eastern Siberia. Our ice data base is only about 40 years old, but we also have some useful bits of data over the past 100 years plus fairly reliable long-term oral history information from the peoples of the north. No one can recall a persistent event like this in the past century(ies) until now. Interestingly, this fits in with some (not all) ice and/or climate model results. BUT: What if those models included only "local" physics? In other words, what if sea ice growth and melting in those models was based mostly on local air temperatures, winds, water temperatures, etc.? And what if, by tweaking the model, they could get the observed 40% reduction in ice volume from the 1960s to the present? Oh boy! We can use this to predict what happens next! But can we? What if "half" of the ice melt, at least in the past 10 years, came about as a result of an increased heat flux carried by the Pacific water inflow to the western Arctic through Bering Strait, and this wasn’t even part of your model? If you are not modeling the correct processes, how good is your model at prediction?
This would be a very good reason to next go out and do some studies to decipher the physical processes at work, to do some re-thinking about your computer model, and so forth. And, more or less, that is going on, at least piecemeal.
So, turning to I8S, we learn a lot more than just how much warmer or colder a parcel of the ocean is since 1994, we get a few more inferences about what makes the oceans tick. Hard to explain. ... maybe I'll try again some day. :)
As for me: At home, we recycle most of our curbside waste, I compost small size yard waste, we have a Prius (and a Subaru), I ride my bike to work 2-3 times each week, I turn off lights, keep the heat low, etc. We eat very few prepared foods (i.e. we cook mostly from less-processed basic ingredients.) But we still live a life style that is utterly and almost unimaginably luxurious to much of the earth's population. These dichotomies are part of life. I'd like to think we will find a way to reconcile some aspect of our lifestyles with minimum harm to peoples and the planet. As an oceanographer-who-measures I chip away.
-- Jim Swift
Professor of Oceanography Chris Measures’s Response:
Hi Debra and class:
It is a little more sane now we are under way to our "final" station -- Fremantle, Australia! I am also hiding out in my van since we are playing the murder game on the ship and I am one of the few left alive, the murderer keeps checking on me but is not allowed to murder me in here!
I know Jim has answered your questions, but I did not see his response so thought I would give a "chemical" response too --I just hope we are saying the same thing!
I also saw the Inconvenient Truth and bought a copy of the book. Nothing in that movie is news to those of us who work in this field, but it is accurate and has done a great job of bringing these issues to public attention, something we scientists have not been able to achieve very well. Unfortunately some in Congress equate Science to Science Fiction, hence their desire to take public testimony on this issue from a science fiction writer, Michael Crichton as equivalent to testimony from real scientists who actually work on these issues!
Anyway on to your real questions, which show a good understanding of the problems, if only our leaders employed such good critical thinking!
I will defer to Jim on the difference between our current data and previous data sets and circulation in coastal California.
But what are the consequences of a change in the global conveyor belt's strength? If we do not move heat northwards in the N Atlantic, then certainly northern Europe that gets the benefit of the Gulf Stream today will get colder, but not anything like that shown in the Day After Tomorrow (a film riddled with errors!). However it is not so simple as to just say it will get colder. The Equatorial regions receive a lot more heat than the higher latitudes and the ocean and the atmosphere move that heat towards the poles. That process will continue regardless of climate change, basic physics demands that this must happen. The question is how will the nature of the movement of the heat change. There is some evidence that in the past when there were big changes in global temperatures (ice ages in this case, i.e. cooler), the circulation of the deep ocean switched. The new circulation was driven mainly by making a lot more deep water in the southern ocean, around Antarctica, rather than near Iceland, so the warm surface waters went to the south not the north. The problem with these ideas is knowing if they are really true, no-one was around then to measure currents so we have to rely on indirect evidence to test our theories.
This is where chemistry comes in. Some of the plants and animals in the oceans build skeletons that, when they die, become the oceans sediments. When these skeletons are being built they also incorporate minute amounts of other chemicals as well. We know from work that we are doing in the oceans today that the amount of some of these chemicals is directly related to things like temperature and other properties of the ocean from which we can tell the oceans circulation. I am simplifying this a bit, but you get the general picture, the tell-tale chemicals, now in the sediments of the oceans, are like clues to a murder (I am trying to avoid my own right now!), these chemicals can help us reconstruct what the ocean looked like say 20,000 years ago during the last ice age. If we can figure out how the ocean worked then, we have a much better chance of predicting how it may work in the future. There are lots of chemicals that might help us do this, but one problem is that we do not know much about how many of them are distributed in the ocean at the moment. We are currently planning a new program that will help us get this information, it is called GEOTRACES, and we are planning on using the CLIVAR program that we are on now as a pattern for how we will do this kind of work. This will be a very large project over about 10 years and we are already starting to involve many countries from around the world, just like CLIVAR has done.
It is good to remember that virtually all of the scientists in our field believe this is a real problem, and that we are working together as an international community to try and get the information we need to make sound policy decisions.
Over the next few years we should start to make some real progress, especially if we have a new generation like you who push our political leaders to take this seriously!
Cheers,
Chris Measures
Dear Anonymous,
I wasn’t able to check the first link, but the second to “The Great Global Warming Swindle”... well, rather than go into a lot of detail about it—because I’m sure you don’t care to hear the “mainstream” arguments about anthropogenic causes of global warming—I’d instead like to point out its web host, “Channel 4.” On this site, you’ll find a section regarding the “Swindle” documentary and its argument that man has no effect on the environment. If you click the “Environment” link in the “Swindle” section, you’ll be taken to another hosted page which describes the dangers of man-made global warming, and what you might do as an individual to help reduce your carbon footprint. This may seem contradictory until you realize that many of Channel 4’s pages disclaim: “Channel 4 is not responsible for the content of third party sites.” Apparently the majority of its pages are third party sites, and are possibly full of poo. If they want attention for the mere sake of controversy, then I guess they’re doing a good job.
Dan
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