The world has never seen such freezing heat

[we_are_toast]

Re: The world has never seen such freezing heat

I told myself that I wouldn't post in this thread again, but here I am demonstrating my weakness for exposing the unreasonable and irrational.

As I said above, this really isn't a thread about Global Warming, it's a demonstration of how people think and reach conclusions. Since the Global warming deniers have rejected all the overwhelming science concerning this subject they by default have rejected the scientific method (a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning) as a method to identify factual information and reach reasoned conclusions. This begs the question, what method are they using when they express opinions or reach conclusions?

The information they present has been debunked, is contrary to the science, and there is not one piece of legitimate data to support their denialist conclusions. I maintain that this method of thinking can not simply be turned on and off and permeates a persons very character. Each person on iTulip needs to determine the legitimacy of the information that is posted here in order to make the critical decisions that face us all. I simply view this thread as a tool to determine how legitimate the information that is being posted on other threads might be.


c1ue:
Your post above demonstrates a lack of even the most basic understanding of atmospheric science, and I don't mean to pick on you, but it's a nice demonstration of how misinformed the denialists are.

2) The next argument is that CO2 has a stronger relative effect than anything else including methane and water vapor

This statement is absoluetely FALSE. It discredits your sources as absolutely laughable.
No scientist even remotely familiar with the impact of greenhouse gases would EVER claim that CO2 has a bigger impact on warming than water vapor. The balance of water vapor has not been disrupted like the balance of CO2 and the earths corrective measures for rebalancing water vapor seem to be more effective than those of CO2. I'm afraid your sources are simply not being honest with you and you are believing them.

The rest of your argument about a CO2 multiplier is so off base as to not even be in the ball park.

If you've ever been to high school science fair, you'll probably see a student which a solar collector. They'll have a large display showing how the sun's visible rays are transparent to the glass, but the Infrared rays generated from the warmth inside the box are opaque to the glass and thus the box warms up. It's the classic example of demonstrating how CO2 and other greenhouse gasses are simply opaque to the IR radiated from the earth. The % of greenhouse gasses in the atmosphere is nearly irrelevant. The more CO2, the more IR is kept near the earth, the warmer things get. It's really that simple.

If I find a website misleads me, I get very angry and avoid that site. I think if you set aside your politics and start looking for supported facts, you might find yourself exploring a whole different group of more interesting and fascinating websites.

[c1ue]

Re: The world has never seen such freezing heat

Lukester,

You still fail to distinguish between

a) Global Warming
b) Man Made Global Warming
c) Carbon emission based Man Made Global Warming

As I noted previously, it seems likely there is a warming trend - after all there was a mini Ice Age just 500 years ago.

But the question again is whether it is man made; whether if man made, the cause is carbon (as opposed to deforestation, urbanization, terraforming caused by farming, etc etc).

Throwing tons of articles concerning the effects of warming on plants, coral, animals, insects does nothing whatsoever to answer ANY of the 3 areas in question.

It is equally interesting to note that there are all sorts of links in your purported 'smoking gun' list which talk about exactly what I noted: water vapor. Methane. Past historical warming cycles that had NOTHING to do with man made CO2.

Another interesting tidbit about CO2: If global warming is due to some OTHER reason - say the sun - that itself could account for CO2 levels in the atmosphere rising. Because as any trout fisherman knows, cold water holds more gases like oxygen. A warming trend that's part of a cyclical temperature uptrend itself theoretically should cause the oceans to warm up thereby releasing massive amounts of CO2 into the atmosphere.

But if this were true, then the CO2 levels are a symptom, not a cause.

Certainly it is possible that man made CO2 itself causes a temperature rise, which in turn causes more CO2 from the oceans to be released thereby creating a positive feedback loop of more man made CO2 = higher ocean temperatures = more CO2 in atmosphere, rinse and repeat.

But equally it could be that CO2 itself is not the factor.

That's why I find it very interesting to see how "thousands of scientists" are somehow concluding all three of the major areas above are fully understood - when neither the modeling nor the mechanisms are yet proven.

Of course there are those who say:

If its true, we will suffer. If it isn't true, then what's the harm in being safe?

This is just Pascal's view on Hell writ onto the 'Save the Planet' ethos.

Unfortunately Pascal conclusion was that if there is no cost to believing and thus avoiding Hell, why not.

But there are very real costs to stopping the majority of human carbon emissions - and like ALL initiatives to do with cost, it will be the poor who suffer.

[c1ue]

Re: The world has never seen such freezing heat

Toast,

Since you understand the CO2/IR relationship so well, please post the specifics of the breakdown between CO2/atmospheric warming effects vs. water vapor vs. other materials such as Methane, planet surface albedo, etc.

I'm curious to see what your trained scientist understanding is.

I will warn you, I have physics training.

[WDCRob]

Re: The world has never seen such freezing heat

c1ue... could you point us to peer reviewed articles in scientific publications that support your position that global warming is NOT in siginificant part based on carbon emissions due to human activity?

Given the current scientific concensus on this point I think the burden of proof is with you to dispute it. Not on the layperson to prove they understand the highly technical ins and outs of the evidence as it exists today.

[ev1]

Re: The world has never seen such freezing heat

It is interesting that the idea for using ENVIRONMENTALISM as a means to increase government control over humanity was discussed in a document called "The Report from Iron Mountain" back in 1966. G. Edward Griffin has an great commentary on the "The Report from Iron Mountain" see the link. It is very interesting that many of the ideas from the Report are being implemented today including global warming /climate change and the global war on terror as a means to replace conventional war as a tool to control humanity.

http://www.freedomforceinternational...n_Mountain.pdf

[jtabeb]

Re: The world has never seen such freezing heat

The temp is lagging the CO2 rise by an enormous amount, but with an 80% correlation between the two spanning half a million years and beyond,

Luke, Question here so don't get defensive. (I'm requesting clairification of my own limited knowledge)

It was my understanding that the whole controversy over "An Inconvenient Truth" was that Temp was LEADING CO2 not CO2 Leading Temp which resulted in a "cause or effect" paradox.

I don't think it is as clear cut as you present.

The included link is representative the scientific papers that ask the question what is really going on.

http://www.oism.org/pproject/GWReview_OISM600.pdf

Also, from my limited understanding. Solar output forcing dwarfs CO2 by TWO orders of magnitude. Hence the recent uproar about the lack of solar flare activity.

See a picture of the sun here:

http://www.spaceweather.com/

Now Contrast that with this:

http://www.whrc.org/resources/online...c_evidence.htm

which very cleary shows global warming as a result of a combination of anthropogenic and natural forcing functions



So, which is correct?

Is there a atmospheric scientist out there on Itulip that would care to comment?

(I sure don't have an answer, JUST a whole heck of a lot of questions)

V/R

JT

[politicalfootballfan]

Re: The world has never seen such freezing heat

----nm----

[Guest]

Re: The world has never seen such freezing heat

Jtabeb - you are indulging in some serious rhetorical jousting here. Sorry. I've lost interest. Run the rhetoric by someone else.

[WDCRob]

Re: The world has never seen such freezing heat

This all sounds supiciously like Carl Sagan's 'Dragon in the Garage' to me...

"A fire-breathing dragon lives in my garage"

Suppose I seriously make such an assertion to you. Surely you'd want to check it out, see for yourself. There have been innumerable stories of dragons over the centuries, but no real evidence. What an opportunity!

"Show me," you say. I lead you to my garage. You look inside and see a ladder, empty paint cans, an old tricycle--but no dragon.

"Where's the dragon?" you ask.

"Oh, she's right here," I reply, waving vaguely. "I neglected to mention that she's an invisible dragon."

You propose spreading flour on the floor of the garage to capture the dragon's footprints.

"Good idea," I say, "but this dragon floates in the air."

Then you'll use an infrared sensor to detect the invisible fire.

"Good idea, but the invisible fire is also heatless."

You'll spray-paint the dragon and make her visible.

"Good idea, but she's an incorporeal dragon and the paint won't stick."

And so on. I counter every physical test you propose with a special explanation of why it won't work.

Now, what's the difference between an invisible, incorporeal, floating dragon who spits heatless fire and no dragon at all? If there's no way to disprove my contention, no conceivable experiment that would count against it, what does it mean to say that my dragon exists? Your inability to invalidate my hypothesis is not at all the same thing as proving it true. Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value they may have in inspiring us or in exciting our sense of wonder. What I'm asking you to do comes down to believing, in the absence of evidence, on my say-so.

Any data proving global warming is suspect (science is bought, man is easily fooled, etc), but the naysayers never provide any real data to support their arguments.

Shouldn't be that hard to produce. One wonders if there is any?

ETA: there are in fact plenty of instances regarding global warming where the 'scientific results' were purchased retail. However they're all on the side of the deniers.

[c1ue]

Re: The world has never seen such freezing heat

c1ue... could you point us to peer reviewed articles in scientific publications that support your position that global warming is NOT in siginificant part based on carbon emissions due to human activity?

Given the current scientific concensus on this point I think the burden of proof is with you to dispute it. Not on the layperson to prove they understand the highly technical ins and outs of the evidence as it exists today.

Again, another attempt at an assumptive close: Given that Man Made Global Warming exists, disprove it.

My point is that Man Made Global Warming is a hypothesis.

It is not proven, and assuming that it is by taking a course of action based on that assumption is silly.

EDIT: Now your latest post talks about disproving something which may not exist. I advise re-reading the scientific method, followed by Sir Karl Popper's treatise on epistemology.

But if you want to look at some info - read up on some of the footnoted sources at the end of this document:

http://brneurosci.org/co2.html

Again, I don't believe or disbelieve global warming exists (yet) although the evidence I have seen leans toward global warming existing.

However, the evidence that this global warming is man made and is due to CO2 is not equally compelling. For one thing, I have seen numerous references to the Global Cooling panic in the '70s. Did the historical data prior to 1970 somehow change from then until now?

Some excerpts: (underline emphasis mine)

You will note that this article doesn't disprove global warming nor does it say it is/is not man made, or even that it is/is not CO2 based. It talks specifically about the physics behind how CO2 might contribute to atmospheric temperature increases.

Note added 9/30/2008:
Several readers have commented on the use of Beer's law here. I am not implying that we can use Beer's law to calculate climate changes. As one reader pointed out, Beer's law only applies to monochromatic light (light whose wavelength is narrow compared to the absorption peak). This reader writes:

What matters for global warming is that, as greenhouse gas concentrations go up, more and more IR wavelengths get captured completely ("saturated absorption"). The relationship at every wavelength is exponential, but that doesn't matter. What matters is the distribution of absorption coefficients across the spectrum (weighted by 255K black body radiation). Greenhouse gas emissions just recruit more and more wavelengths into saturation.

Of course, this is somewhat of an oversimplification, because a spectrophotometer never measures a single wavelength; it always measures a band of finite width. Across that band, you always have a logarithmic function. What this reader is actually saying is that if the concentration increases, those wavelengths at the edges of the absorption band will absorb more energy over a given distance.
As another reader pointed out, Beer's law was derived for a single beam of light going through a gas or solution for which the reemitted radiation does not enter the detector. Therefore, Beer's law will not fit the situation precisely, but there is general agreement that the curve is approximately logarithmic in shape.

The net effect of all these processes is that doubling carbon dioxide would not double the amount of global warming. In fact, the effect of carbon dioxide is roughly logarithmic. Each time carbon dioxide (or some other greenhouse gas) is doubled, the increase in temperature is the same as the previous increase. The reason for this is that, eventually, all the longwave radiation that can be absorbed has already been absorbed. It would be analogous to closing more and more shades over the windows of your house on a sunny day -- it soon reaches the point where doubling the number of shades can't make it any darker.

The analogy with a greenhouse would be that the glass in the roof becomes slightly thicker. The effect of warming also depends on the conditions inside the greenhouse. If the greenhouse were full of ice at exactly -0.01 degrees Celsius, making the glass slightly thicker just might be enough to melt all the ice and flood the greenhouse. But if the greenhouse had some regions that were hot and some that were very cold (as the planet Earth does), it would have a very small overall effect.

1. The "saturation" argument does not mean that global warming doesn't occur. What saturation tells us is that exponentially higher levels of CO2 would be needed to produce a linear increase in absorption, and hence temperature. This is basic physics. Beer's law has not been repealed.
2. Some people have gotten the idea that water vapor, which is mainly present at lower altitudes, is somehow necessary for the CO2 to absorb infrared radiation, and that therefore at higher altitudes, CO2 is not anywhere near saturation. This is not true. The presence or absence of water vapor has no bearing on whether radiation is absorbed by CO2. That is because, for all practical purposes, the absorption bands of H2O and CO2 important for warming are different. (If they weren't, CO2 absorption would be so insignificant compared to water vapor that it wouldn't be a potential problem, and we wouldn't be having this discussion.)
3. CO2 is very nearly homogeneous throughout the atmosphere, so its concentration (as a percentage of the total) is about the same at all altitudes. Although the pressure is lower at high altitudes, there is also a much greater volume. That is why the ozone layer, which is around 30-90 km in altitude, is still able to absorb almost all of the shortwave UV, even though its concentration is only 8-12 ppm. So the importance of low concentrations of gases should not be underestimated. But water vapor is a red herring: it has essentially no effect on what CO2 does. Where water vapor becomes important is in the earth's response to CO2.
4. Some people also think that line broadening of the CO2 absorption lines by pressure, water vapor, or temperature provides an escape from the saturation dilemma. But in line broadening, the absorbance is peak is only smeared out; the total amount of energy absorbed is not affected. For the same reason, measurements with lower-resolution spectrometers, which slightly smear out the absorption lines, are still valid.

So, what is the actual increase? Interestingly enough, that is easy to estimate--and without resorting to complex computer models.
Because a linear increase in temperature requires an exponential increase in carbon dioxide (thanks to the physics of radiation absorption described above), we know that the next two-fold increase in CO2 will produce exactly the same temperature increase as the previous two-fold increase. Although we haven't had a two-fold increase yet, it is easy to calculate from the observed values what to expect.

Between 1900 and 2000, atmospheric CO2 increased from 295 to 365 ppm, while temperatures increased about 0.57 degrees C (using the value cited by Al Gore and others). It is simple to calculate the proportionality constant (call it 'k') between the observed increase in CO2 and the observed temperature increase:
This shows that doubling CO2 over its current values should increase the earth's temperature by about 1.85 degrees C. Doubling it again would raise the temperature another 1.85 degrees C. Since these numbers are based on actual measurements, not models, they include the effects of amplification, if we make the reasonable assumption that the same amplification mechanisms that occurred previously will also occur in a world that is two degrees warmer.
If we want to include other greenhouse gases, such as methane, in the calculation, we need to use the "effective" CO2 concentrations instead. These effective CO2 numbers are less solid than the CO2-only numbers, but the best estimates are that effective CO2 increased from 305 to about 450 ppm during the 20th century[12]. Using these numbers, k becomes 0.6823 and the predicted ΔT becomes 1.02 degrees.

What is the scale of CO2 buildup?

global-co2-extrapolated.png

Note added 1/5/2008:
Some authors [15] suggest that the percentage of warming attributable to CO2 is not 5%, but is closer to 26%. It is easy to show why the 26% estimate (and estimates similar to it) are almost certainly wrong. We know that the total warming from greenhouse gases is 33K. If 26% of this was from CO2, then doubling CO2 would raise temperatures by 0.26*33 or 8.6K. Since the 26% estimate is based on total radiation absorbed, and not the amount of warming, we would have to add secondary feedback effects to this figure. This would double or even triple the value, giving us a predicted temperature increase of up to 25° C, or a predicted global average temperature of 40°C (104°F). Balmy!
Whether the exact number is 5% or 9%, because our estimate is based on the percentage of warming, not percentage of radiation absorbed, that is attributable to CO2, feedbacks in the estimate here are automatically taken into account. However, because of the large uncertainty about the actual value, the estimate from Fig. 3 (which derives an estimate from extrapolation of current trends) is probably more accurate.
However, we can also check the plausibility of the IPCC's result by asking the following question: What number would result if we calculated backwards from the IPCC estimates? Using the same assumption of linearity, if a 9 degree increase resulted from the above-mentioned increase of greenhouse gas levels, the current greenhouse gas level (which is by definition 100%) would be equivalent to a greenhouse gas-induced temperature increase of at least 107 degrees C. This means the for the 9 degree figure to be correct, the current global temperature would have to be at least 255 + 107 - 273 = 89 degrees centigrade, or 192° Fahrenheit! A model that predicts a current-day temperature well above the highest-ever observed temperature is clearly in need of serious tweaking. Even a 5 degree projection predicts current-day temperatures of 41°C (106°F). These results clearly cannot be reconciled with observations.

Note that the first few excepts show temperature effects from CO2 should be logarithmic - i.e. inversely exponential to CO2 levels. Linear extrapolation is also clearly wrong.

Thus either the IPCC conclusions are flawed or the actual mechanism is exponential - which unsurprisingly is what exactly 'Carbon Forcing' says.

Seems like more of fitting theory to desire than data to facts.

[c1ue]

Re: The world has never seen such freezing heat

Also, from my limited understanding. Solar output forcing dwarfs CO2 by TWO orders of magnitude. Hence the recent uproar about the lack of solar flare activity.

See a picture of the sun here:

http://www.spaceweather.com/

Now Contrast that with this:

http://www.whrc.org/resources/online...c_evidence.htm

which very cleary shows global warming as a result of a combination of anthropogenic and natural forcing functions



So, which is correct?

JT,

Just as we look to past behavior to predict future results, so too does an examination of the Woods Hole staff bear this method out.

In contrast, the other site just provides facts.

Who's Who at The Woods Hole Research Center

Staff Bios

Scientific and Policy Staff

John P. Holdren, Ph.D.
Director
Dr. Holdren was Visiting Distinguished Scientist at the Center from 1991-2005 and became Director in June of 2005. He has been the Teresa and John Heinz Professor of Environmental Policy at Harvard since 1996 and previously was the Class of 1935 Professor of Energy at the University of California, Berkeley. He was named president-elect of the American Association for the Advancement of Science (AAAS) in 2005, and is presently serving a year as president beginning in February of 2006. Trained in engineering and theoretical plasma physics at MIT and Stanford, Dr. Holdren's research interests include causes and consequences of global environmental change, energy and resource options in industrial and developing countries, and nuclear arms control and nonproliferation. He is a former MacArthur Prize Fellow and a member of the National Academy of Sciences, the National Academy of Engineering, and the American Academy of Arts and Sciences. In 1995 he accepted the Nobel Peace Prize on behalf of the Pugwash Conferences on Science and World Affairs, for which he served as chair of the executive committee from 1987 to 1997.
Richard A. Houghton, Ph.D.
Deputy Director and Senior Scientist
Dr. Houghton is an ecologist with interests in the role that terrestrial ecosystems play in climate change and the global carbon cycle. He co-ordinates the Center's efforts to understand the problems of global warming and climate change, especially the role biotic systems play in this accelerating process. Dr. Houghton has held positions as Assistant Scientist at the Ecosystems Center of the Marine Biological Laboratory and as Research Associate at Brookhaven National Laboratory. He earned his doctorate in ecology from SUNY at Stony Brook.
George M. Woodwell, Ph.D.
Founder, Director Emeritus, and Senior Scientist
Dr. Woodwell is an ecologist with broad interests in global environmental issues and policies. Prior to founding the Woods Hole Research Center, he was founder and director of the Ecosystems Center of the Marine Biological Laboratory in Woods Hole and a senior scientist at Brookhaven National Laboratories. He was also a founding trustee and is vice chairman of the board of the Natural Resources Defense Council. He is a former chairman of the board of trustees and currently a member of the National Council of the World Wildlife Fund, a founding trustee of the World Resources Institute, a founder and currently an honorary member of the board of trustees of the Environmental Defense Fund, and former president of the Ecological Society of America. Dr. Woodwell is the author of more than 300 major papers and books in ecology. He holds a doctorate in botany from Duke University and is the recipient of several honorary degrees as well as the 1996 Heinz Environmental Award and the Volvo Environment Prize of 2001. He is a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences.

---

Alessandro Baccini, Ph.D.
Project Scientist
Dr. Baccini is a remote sensing scientist whose interests focus on the use of satellite data for the monitoring of forest carbon, land cover, land cover change and the effects of environmental change on the terrestrial carbon cycle at the regional and global scale. Before joining the Center he was a research associate at Boston University and worked at the Food and Agriculture Organization of United Nations for the Forest Resources Assessment 1990 and 2000 monitoring tropical deforestation. He received his doctorate from Boston University.
Pieter S. A. Beck, Ph.D.
Postdoctoral Fellow
Dr. Beck is a vegetation ecologist who specializes in remote sensing and modeling of vegetation in high latitudes. His particular focus is on the effects of climate variability and change on the phenology, distribution, and carbon dynamics of vegetation. Dr. Beck has previously worked as an independent advisor for environmental impact assessment in northern Scandinavia. He obtained his Ph.D. from the University of Tromsø, Norway, and the Institute for Geo-Information Science and Earth Observation (ITC) in the Netherlands.
I. Foster Brown, Ph.D.
Senior Scientist
Dr. Brown is an environmental geochemist whose research interests focus on what constitutes and how to attain sustainable development in the Amazon Basin. He coordinates the Center's program dealing with deforestation, water quality, and land use in the Brazilian Amazon and directs the program for human resource development in Third World countries. Dr. Brown spent over five years as a faculty member of the Graduate Program in Environmental Geochemistry at the Federal Fluminense University in Niteroi, Brazil, and is currently on the faculty of the Federal University of Acre, Brazil. He earned his doctorate in environmental geochemistry at Northwestern University.
Ekaterina Bulygina, M.S.
Research Assistant
Ms. Bulygina manages the Center's Luce Laboratory of environmental chemistry. She has extensive experience in laboratory management and has worked at Moscow State University's museum of zoology and in the chemistry laboratory of the Upstate Fresh Water Institute, Syracuse, NY. Ms. Bulygina received her master's degree in ecology and hydrobiology from Moscow State University.
Andrea Cattaneo, Ph.D.
Senior Scientist
Dr. Cattaneo is an economist whose research focuses on the economics of tropical deforestation, in particular linking economy-wide models of drivers of deforestation to geographic information systems. He has experience in analyzing the design of payment programs for ecosystem services, the role of monitoring on program performance, and the use of environmental indices in the context of multi-objective decision-making when monetary valuation estimates are not available. Before joining the Center, Dr. Cattaneo worked for the International Food Policy Research Institute (IFPRI), the Economic Research Service (ERS) of the U.S. Department of Agriculture, and the Organisation for Economic Co-operation and Development (OECD). He obtained a Master of Science in Engineering (M.S.E.) in electrical engineering at the University of Pavia (Italy), and from Johns Hopkins University he received a second M.S.E. in Environmental Systems Analysis and his Ph.D. in Economics and Systems Analysis.
Michael T. Coe, Ph.D.
Associate Scientist
Dr. Coe is an earth system scientist who is particularly interested in the causes and consequences of water resource variability. He uses data and earth system computer models to study how climate variability interacts with human land and water management practices to cause changes in water quality and quantity. He is currently participating in projects in the Amazon and Mississippi River basins as well as the semi-arid regions of northern Africa. Dr. Coe previously spent seven years as a scientist at the Center for Sustainability and the Global Environment, University of Wisconsin-Madison and has been a visiting scientist at Lund University, Sweden, and the Max Planck Institute for Biogeochemistry, Jena, Germany. He received his Ph.D. in Atmospheric and Oceanic Sciences at the University of Wisconsin-Madison.
Eric A. Davidson, Ph.D.
Senior Scientist / Co-Leader of Amazon Program
Dr. Davidson is an ecologist and soil scientist interested in the role of soil microorganisms as processors of carbon and nitrogen. He has studied the transfer of carbon and nitrogen gases from the soil to the atmosphere, where they contribute to warming of the earth. His research addresses how human management of the land affects this transfer of greenhouse gases. Dr. Davidson has held positions as National Research Council Associate at the NASA Ames Research Center and as Postdoctoral Research Associate in Soil Microbiology at the University of California, Berkeley. He earned his doctorate in forestry at North Carolina State University.
Gregory J. Fiske, M.S.
GIS Manager
Mr. Fiske is a geographer interested in the use of cartography and other techniques of modern geographic information science to sustain the health of the natural environment. He works in the Center's Remote Sensing and Geographic Information Systems Laboratory. Prior to joining the Center, Mr. Fiske was an intern at Lawrence Livermore National Laboratory. He has worked as a research assistant on a project dealing with the status of the world's international river basins. He earned his B.S. from Plymouth State University in New Hampshire and his M.S. from Oregon State University.
Scott Goetz, Ph.D.
Senior Scientist
Dr. Goetz works on the application of satellite imagery to analyses of environmental change, including monitoring and modeling links between land use change, forest productivity, biodiversity, climate, and human health. Before joining the Center, he was on the faculty at the University of Maryland for seven years, where he maintains an adjunct associate professor appointment, and was a research scientist at NASA's Goddard Space Flight Center. He received his Ph.D. from the University of Maryland.
Nora Greenglass, M.E.M.
Research Assistant
Ms. Greenglass is currently engaged in an effort to examine the role of forests in carbon storage in the northeastern United States. Other recent projects include an analysis of local and state climate policies in the United States as well as international carbon mitigation strategies. Her master's research focused on climate protection strategies for the electric utility sector in the southeastern United States. She received her B.A. in geology and environmental studies from Middlebury College and a Master of Environmental Management from Duke University.
Joseph L. Hackler, M.A.
Research Associate
Mr. Hackler works on computer models incorporating regional data on changing land use and vegetation cover to understand the global carbon cycle. He has worked as a provincial planner in the Solomon Islands as a Peace Corps volunteer and as a neighborhood planner for the City of Columbus, Ohio. Mr. Hackler received his master's degree in city and regional planning from Ohio State University.
Robert Max Holmes, Ph.D.
Associate Scientist
Dr. Holmes is an earth system scientist with broad interests in the responses and feedbacks of ecosystems to environmental and global change. Most of his current research takes place in the Arctic (field sites are in Russia, Canada, and Alaska) and addresses how climate change is impacting the cycles of water and chemicals in the environment. Dr. Holmes has also studied desert streams in the southwestern United States, stream/riparian ecosystems in France, and estuaries in Massachusetts. He is strongly committed to integrating education and outreach into his research projects, particularly by exposing K-12 and undergraduate students to the excitement of scientific research. Students around the Arctic are participating in his Student Partners Project, and in 2008 he initiated a new effort (The Polaris Project) that includes a summer field course for U.S. and Russian undergraduate students in the Siberian Arctic. Dr. Holmes earned his Ph.D. from Arizona State University, his M.S. from the University of Michigan, and B.S. from the University of Texas.
Holly Hughes, B.S.
Research Assistant
Ms. Hughes works on the Center's carbon cycling research program in the Howland, Maine forest. Previously she managed a soil warming project in Howland where she studied the effects of soil warming on carbon flux through the forest floor, as well as other environmental indicators. Prior to joining the Center staff, she worked on a research project for Rutgers University designed to help farmers reduce their use of chemicals. Ms. Hughes received a B.S. in natural resources with a concentration in soil science from the University of Maine.
Tracy Johns, M.S.
Policy Advisor / Co-Leader of REDD Initiative
Ms. Johns is a policy analyst specializing in the Center's programs in forest, climate, and energy-policy issues. She helps coordinate the policy activities of the Center related to the role of forests in climate. She also works with members of the Amazon and Africa programs on efforts related to monitoring deforestation, focusing on international, national and regional policies and programs to reduce deforestation, as well as efforts to include relevant local and regional stakeholders in the policy design and implementation process. She works with international and U.S.-based NGOs to develop and support strong climate and energy policies, both internationally and at the federal and state level. Ms. Johns received her M.S. from Arizona State University's Center for Science, Policy and Outcomes in Forest Ecology and Environmental Policy.
Josef Kellndorfer, Ph.D.
Associate Scientist / Co-Leader of REDD Initiative
Dr. Kellndorfer's research focuses on the monitoring and assessment of terrestrial and aquatic ecosystems. Using geographic information systems (GIS) and remote sensing, he studies land-use, land cover and climate change on a regional and global scale. Currently, he is leading a NASA-funded project to generate the first high-resolution aboveground biomass and carbon dataset of the United States based on the integration of space shuttle radar and satellite imagery. Before joining the Center, he was an assistant research scientist with the radiation laboratory in the department of electrical engineering and computer science at the University of Michigan. Dr. Kellndorfer holds a degree in physical geography and a doctorate in geosciences from the Ludwig-Maximilians-University in Munich, Germany.
Wendy Kingerlee, B.S.
Research Assistant
Ms. Kingerlee works with both the Amazon and Soil Carbon programs. Prior to joining the staff she worked for the Agriculture Department in the County of Santa Cruz, California. Ms. Kingerlee received her bachelor's degree from the University of Massachusetts, Amherst, where she studied plant and soil science.
Katie Kirsch, B.A.
Research Assistant
Ms. Kirsch works on the Center's National Biomass and Carbon Dataset project in the Remote Sensing and Geographic Information Systems (GIS) Laboratory. Prior to joining the Center, she completed a post-graduate diploma program in remote sensing and GIS for geo-hazard assessment as a Fulbright scholar in the Netherlands. She has interned at the Monterey Bay National Marine Sanctuary and at Lamont-Doherty Earth Observatory. She received her B.A. in geology and environmental studies from Middlebury College.
Nadine T. Laporte, Ph.D.
Associate Scientist
Dr. Laporte is a biologist whose research centers on the applications of satellite imagery to tropical forest ecosystems, including vegetation mapping, land-use change, and deforestation causes and consequences. She has been involved in numerous environmental projects in Central Africa over the past ten years, working with in-country scientists, foresters, and international conservation organizations to develop integrated forest monitoring systems and promote forest conservation. She received her doctorate in tropical biogeography from l'Université Paul Sabatier in Toulouse, France.
Paul A. Lefebvre, M.A.
Research Associate
Paul Lefebvre uses Geographic Information Systems to monitor ongoing changes in landcover in the Amazon basin, and to contribute data to our forest ecosystem models. Since 1989 he has advised many of of WHRC's Brazilian Visiting Scholars on the use of GIS and Remote Sensing in their research, and from 1995 to 1998 he lived in Brazil while helping to establish IPAM's Remote Sensing and GIS laboratory. He loves to tinker, and is responsible for setting up and maintaining many of the monitoring instruments used at our field stations in Brazil. He holds a Master of Arts degree in Geography from the University of California, Santa Barbara.
David G. McGrath, Ph.D.
Associate Scientist / Co-Leader of Amazon Program
Dr. McGrath is a geographer who, in collaboration with the Center's partner organization in Brazil, Instituto de Pesquisa Ambiental da Amazonia (IPAM), coordinates projects to develop ecologically and economically sustainable community-based management systems for forest and floodplain resources. On a broader level, McGrath is interested in the relationship between population, technology and environment in human history and its implications for environment and development policy. He holds a Ph.D. in geography from the University of Wisconsin-Madison and is a faculty member at the Federal University of Pará in Belém, Brazil.
Frank D. Merry, Ph.D.
Associate Scientist / Co-Leader of REDD Initiative
Dr. Merry is a resource economist whose research focuses on forest policy for the Amazon including economic models of the timber sector-primarily in Brazil, Bolivia, and Peru-and the economic analysis of small farm systems in both migrant settlements and floodplain communities. In addition to research, Dr. Merry participates in community development projects to make better use of the forest resource in migrant settlements on the Transamazon highway. He is also Associate Researcher at the Amazon Institute of Environmental Research (IPAM) and Research Fellow in Environmental Sciences at Dartmouth College. A citizen of Trinidad and Tobago, Dr. Merry has worked in Trinidad, Venezuela, Senegal, Bolivia, Peru, and Brazil. He received his Ph.D. in Forest Resources and Conservation, with a focus on Forest Economics and International Forestry, from the University of Florida.
Paulo Moutinho, Ph.D.
Adjunct Associate Scientist
Dr. Moutinho is an expert in biodiversity and ecological ecosystems in the Amazon region and works on these issues at the Center. During the last decade and as Director of Research of the Instituto de Pesquisa Ambiental da Amazônia (IPAM), he has designed and led a large-scale interdisciplinary research program on the dynamics of deforestation in the Amazon. Since 2002 he has been the coordinator of the Climate Observatory, a network of 32 Brazilian NGOs, and Social Movements for Climate Change, and is a member of the Working Group on Climate Change of the Brazilian Environmental Ministry and member of the Brazilian Forum on Climate Change. He has further collaborated with an international group of scientists on the design of policies to create incentives for reducing deforestation within the structure of the UN Framework Convention on Climate Change. He received both his master's degree and Ph.D. in ecology from Universidade Estadual de Campinas (UNICAMP).
Kilaparti Ramakrishna, Ph.D.
(On leave of absence, 2/2006 - 2007)
Dr. Ramakrishna holds the Center's Sara Shallenberger Brown Chair in Environmental Policy. He is an expert in international environmental law and directs the Center's Program on Science in Public Affairs. He is responsible for international issues including law and policy aspects associated with global climate change, conservation and utilization of world forests, biodiversity, environmental governance, and developing country perspectives. Dr. Ramakrishna served as a special advisor to the UN in drafting the Framework Convention on Climate Change. He helped establish an independent World Commission on Forests and Sustainable Development, and worked with the Secretariat for the Convention on Biological Diversity. He has been a Visiting Professor of International Law at the Fletcher School of Law and Diplomacy, Tufts University, since 1993, was a Fulbright Visiting Scholar at Harvard Law School, and a Fellow at the Marine Policy Center of the Woods Hole Oceanographic Institution. Dr. Ramakrishna is a Fellow of the World Academy of Art and Science, a member of IUCN's Commission on Environmental Law, and the Council on Foreign Relations. He holds a doctorate in international law of environment from the Jawaharlal Nehru University in New Delhi.
Sudeep Samanta, Ph.D.
Assistant Scientist
Dr. Samanta's present research addresses the process of water and carbon exchange between forests and the atmosphere. He uses statistical methods to integrate scientific knowledge and observations in building and testing numerical models of complex natural systems. One of his main interests is to quantitatively estimate uncertainties in model results due to incomplete observation or understanding. He received his M.S. in remote sensing and GIS and his Ph.D. in forestry from the University of Wisconsin.
Kathleen Savage, M.Sc.
Research Associate
Ms. Savage is currently working in the Center's carbon cycling program. She obtained a B.Sc. degree and an M.Sc. degree in Geography at York University and McGill University, respectively. Her thesis work examined the exchange of carbon dioxide and methane in boreal forest soils. Following her graduate studies, she has worked on contract in northern Manitoba examining net ecosystem exchange in boreal wetlands.
Karen Schwalbe
Research Assistant
Ms. Schwalbe works for the Center's Brazilian Amazon program. She worked previously at The Center for the Restoration of Waters at Ocean Arks International as a project manager for a pond restoration study and for an ecological wastewater treatment facility in Albany, Indiana. Ms. Schwalbe has also worked at the New Alchemy Institute in their educational program and as the Volunteer Coordinator. She has broad experience as a research and technical assistant through Boston University and the Marine Biological Laboratory.
Jared Stabach, M.S.
Research Assistant
Mr. Stabach works in the Geographic Information Systems (GIS) and Remote Sensing Laboratory on the Center's Africa program, monitoring changes and threats to the rainforests and threatened species throughout the Central Africa region. His master's research focused on the use of remote sensing technologies to identify Matschie's tree kangaroo habitat in Papua New Guinea. He received his B.S. from Providence College and his M.S. from the University of Rhode Island.
Thomas A. Stone, M.A.
Senior Research Associate
Mr. Stone is an environmental geologist studying the use of remote-sensing technology to map vegetation and to determine rates of land use change. He uses remote-sensing imagery to determine the rates of deforestation globally, especially in Siberia and the Amazon Basin of Brazil. The results of this work assist in the determination of biotic contributions to the global warming problem. Before joining the Center, Mr. Stone held a research position in remote sensing at the Ecosystems Center of the Marine Biological Laboratory in Woods Hole. He holds a master's degree in geology from Dartmouth College.
Mindy Sun, M.S.
Research Associate
Ms. Sun studies the influences of land-use change and vegetation cover on ecosystems. Through the use of remote sensing data and GIS, she works with computer models that can be used to describe and predict changes to the environment. Prior to joining the Center, she spent two years working as an environmental engineer. She received her B.S. in environmental engineering from Cornell University and her M.S. from Johns Hopkins University.
Wayne S. Walker, Ph.D.
Research Associate
Dr. Walker is an ecologist interested in the application of remote sensing and GIS technologies to the assessment and monitoring of forest ecosystems. In particular, his work focuses on the provision of broad-scale measurements and maps of forest structural attributes (e.g., canopy height, aboveground biomass, etc.) and land cover/land use change for use in climate modeling, habitat management, and ecosystem conservation. He holds degrees in forest ecology (M.S.) and remote sensing (Ph.D.) from the University of Michigan.
Richard S. Williams, Jr., Ph.D.
Adjunct Senior Scientist
Dr. Williams is a research geologist who uses airborne and satellite remote sensing to monitor changes in the Earth's glaciers (particularly sensitive indicators of global warming). He is author of more than 200 books, papers, and maps. He holds a doctorate in geology from Penn State, is a fellow of the AAAS, the Geological Society of America, and a foreign fellow of the Icelandic Science Society. Two glaciers in Antarctica are named for him. He is Vice Chairman Emeritus, Committee for Research and Exploration, National Geographic Society, and senior scientist with the U.S. Geological Survey.

[politicalfootballfan]

Re: The world has never seen such freezing heat

----nm----

[yernamehear]

Re: The world has never seen such freezing heat

Quote:

"Your post above demonstrates a lack of even the most basic understanding of atmospheric science,"

Hmmm. OK:

Quote:
"CO2 and other greenhouse gasses are simply opaque to the IR radiated from the earth. The % of greenhouse gasses in the atmosphere is nearly irrelevant. The more CO2, the more IR is kept near the earth, the warmer things get. It's really that simple."

No. Not quite that simple. The heating is what is called forcing by CO2 because it accumulates. The water cycles as is well known, but the science around how repeatable those cycles are is in dispute. It's not known exactly what the water impact is vs. CO2 even though one side simply dismisses it (e.g. "it's that simple"). Water and methane have larger molar absorbtivity coefficients, so on a concentration basis they are more powerful IR absorbers and emitters.

Quote:
" I get very angry and avoid that site."

The problem: this has a socio-political approach, not science. Again, "peer-reviewed" journals, the number of them, has absolutely NO bearing on whether something is true or not.

Note: I have spent many hours studying spectra of molecules in the IR, have published in "peer reviewed" journals. I get paid to do that.

My mind is open. I don't know the answer and my reading of the "peer reviewed" journals doesn't convince me that there is global warming caused by humans. In fact, and this is even more important, it's not clear that the models and measurements are statistically meaningful enough that they could even show whether or not we have global warming.

[xtronics]

Re: The world has never seen such freezing heat

Xtronics posted a seemingly measured comment on this question, but the referenced material has large question marks plastered all over it's methodology.

Please point out any flaws in methodology. Otherwise it is just name calling.

So here's a question for all you beatifically convinced "debunkers" of the warming thesis:

The argument linked to on the xtronics web page evidences a 30 year temp chart around which are draped what are supposed to be trenchant arguments but don't seem to get their teeth into any substantive issue whatsoever. Anyone with a genuinely skeptical approach to this topic knows that taking a 30 year sliver of a secular dataset to develop substantive arguments on global warming is parading a red herring to begin with. You need to be examining 500 year charts out to half million year charts to glean the broadest hints of what may or may not be breaking out of the ecosystem trends. That's the whole point, right?

Actually, that is the point. There isn't any historical data that measures global temperature with meaningful error analysis that is anything close to the 30 year data. The 30 year data does not support their theories - it might in 40 years - but not today. Until good data can support such claims, we simply can not know.

The burden of proof is not to prove the negative. I could be convinced that CO2 is a threat, but not by what is pretending to be hard science.

When ever we look back on history, what happed has to be reconstructed indirectly. To claim known error bands requires some method of calibration.
To KNOW the global temperature of thousands of years ago to the accuracies claimed would take a satellite system that of course did not exist. This might be an amazing idea to some - but there are some things we can not know with any sort of meaningful confidence.

It is a human frailty to want to know things with certainty. There are many things that just are not knowable.

The problem with the hockey-stick-team data is the assumptions, statistical methods, and error analysis. This does not mean that their theory is wrong - but they have the burden of proving it is right. Improper splicing of data, cherry picked data, using 'Texas-sharpshooters fallacies' improper infilling, nonstandard (and distorting) smoothing with techniques that are not part of the published literature of statistical science discredits their efforts. http://www.climateaudit.org/ does a good job of documenting the problems with the data without taking a position on the ultimate truth (which to me, looks like a religious article of faith for both sides).

What bothers me is, if the hockey-stick-team has such a good case, why do they use unpublished statistical methods, refuse to share archived data and force people to use FOI(Freedom of Information act) laws to review publicly funded research data? Peer review is helpful, but less helpful if only best buddies review each others work. The lack of review coments about the statistical methodology is amazing. The review process has failed to provide quality papers IMHO.

Now, I don't pretend to know the exact magnitude of the medieval warming period, but I do know what real science looks like. It takes more than lab coats and computers to do real science. It takes a dedication to a form of honesty that requires people to bend over backward to find fault in their own work. Take the tenent: "A scientists first job is to prove himself wrong." Is that what hockey-stick-team claims resemble?

[Guest]

Re: The world has never seen such freezing heat

Clue - no, your own argument is a red herring. Here is the substantive point ( you and I took one tour around this core issue once before I recall a year or so ago but I don't believe you did offer a direct answer to it then ).

Take a half million year plot of CO2 and temp. Take careful note of the very high correlation between the two (at least 80%++). Then take note of present day CO2 readings a full standard deviation above half million year channel, and take note that by virtue of an 80% correlation across a very long data sample, these two are highly likely to need to "normalize" relative to each other. Take note of the fact the world is highly likely destined to rely ever more heavily on coal if Peak Cheap Oil really starts to bite.

Now look at the fact that whether temp is leading CO2 or whether CO2 is leading temp is a irrelevant to the broadest parts of the GW question. It matters not which leads the other - all that matters is that they have one of the most robust correlations imaginable, what looks to a cursory visual inspection like 80%+ over a half million years. The elementary insight being, that when you see a gap between temp and CO2 in the present day which implies almost overwhelming probability that they must "normalize" by closing the large gap between them, you need only ask yourself whether CO2 readings will collapse, or whether temp readings must instead ramp up to catch up with the CO2.

A half million years of data show that they don't like being this far apart for very long. Whichever one is "leading" does not matter. Indeed, the serious scientists in the GW community seem to acknowledge a possibility that temp leads the CO2, leading to a conundrum. Why is the CO2 soaring far ahead of the temp in modern times? The answer that leaps out at you is that the CO2 is being pushed up anomalously by the world's surge from 1 billion to 7 billion industrialising in the space of a single century. It is the quite obviously steepening part of the demographic growth curve at work.

Why have people who are so curiously hostile to the global warming possibility studiously ignored commenting on the simple yet thorny question to do with this point, posed by the simple half million year charts? Answer the simple question posed by the chart. In case you are tempted to squirm away from that simple question, allow me to reiterate it. When you see a very high correlation across hundreds of thousands of years between Temp and CO2, and you see full standard deviation gap emerge right in the present day, between that Temp and CO2, what do you have to say about the probability that these two readings must normalize, and what do you have to say about the probability that the CO2 will come down to normalize, rather than the temp rise instead?

And here below is an exposition of (one view of) the science behind the CO2 > Global Warming linkage, which I've read recommended as one of the most robust and straightforward, by a reasonably qualified proponent. He's a statistician, chemical engineer and biomedical engineer (Mr. Bruce Tabor). Go ahead and chew on all of this, since you find such assertions to be based on flim flam science. Then answer the question that has been put to people of your ilk here by several of us. Please provide an equivalent list of reference articles by scientists who have coherently and robustly disproved the CO2 > Temp linkage. Or failing that, please reply simply and directly to the apparently very high correlation between CO2 and Temp in this chart. Simple, clear, frank answers are of course always appreciated.

Finally, I am not "failing to distinguish" much of anything - as I dispense with the red herring arguments and look for the broadest common denominator arguments (which upend all the other fragmented and noise-filled objections when validated). It would appear rather that you are (ingenuously or disingenously is to me immaterial) "failing to distinguish" that the overwhelmingly probable future normalization of temp with CO2 would cause any conscientious and sincere husband of the planet to regard this CO2 trend with some concern. The temp has some serious responding to do here, to normalize to the CO2 - that's not an "assumption" - it is the empirical conclusion based on their ratio of correlation spanning 500,000 years.

Lukester,

You still fail to distinguish between

a) Global Warming
b) Man Made Global Warming
c) Carbon emission based Man Made Global Warming

ANSWER THIS CHART: HOW LIKELY IS IT THAT TEMP AND CO2 MUST "NORMALIZE" TOWARDS EACH OTHER HERE? AND DOES THIS PROBABILITY OF NORMALIZATION NOT EVIDENCE THAT WHICHEVER ONE LEADS THE OTHER IS IRRELEVANT?

CO2 CONCENTR AND TEMP - UNCORRELATED IS A SPECIOUS ARGUMENT.jpg


Bruce Tabor Says:


9 September 2008 at 7:36 AM

“These people, typically senior engineers, get suspicious when experts seem to evade their question.”

Before I became a statistician I was a chemical engineer and then a biomedical engineer.

It is perhaps the evasiveness that enginees are responding to. Engineers tend to be distrustful of pat answers. But I would have thought physicists would have been more of a problem in that they prefer to see an eplanation reduced to first principles. (Admitedly much of the physics engineers encounter at university is of this variety.)
Engineers are not strangers to complexity - although this may vary by dscipline. Much of what they do cannot be reduced to first principles and is ultimately empirical. Chemical engineers (& others) often work with dimensionless equstions. Relationships of quantities that have been expeimentally derived, and since they are dimensionless, can be scaled to the situation at hand. Furthermore engineers often resort to computer models in the design of chemical reactors, structures, circuits etc. They could no more summarise one of their own complex systems in 6 pages than you can summarise AGW.


I suspect it is a culture clash that is causing the problem, not an incapacity to accept that a simple derivation is all that is required. For most engineers, Gavin’s “The CO2 problem in 6 easy steps” *should be* and excellent start.
RealClimate.org


Climate science from climate scientists (Gavin Schmidt)

We often get requests to provide an easy-to-understand explanation for why increasing CO₂ is a significant problem without relying on climate models and we are generally happy to oblige. The explanation has a number of separate steps which tend to sometimes get confused and so we will try to break it down carefully.

Step 1: There is a natural greenhouse effect. The fact that there is a natural greenhouse effect (that the atmosphere restricts the passage of long wave (LW) radiation from the Earth's surface to space) is easily deducible from i) the mean temperature of the surface (around 15°C) and ii) knowing that the planet is roughly in radiative equilibrium. This means that there is an upward surface flux of LW around (~390 W/m²), while the outward flux at the top of the atmosphere (TOA) is roughly equivalent to the net solar radiation coming in (1-a)S/4 (~240 W/m²). Thus there is a large amount of LW absorbed by the atmosphere (around 150 W/m²) - a number that would be zero in the absence of any greenhouse substances.
View Step 2

Step 2: Trace gases contribute to the natural greenhouse effect. The fact that different absorbers contribute to the net LW absorption is clear from IR spectra taken from space which show characteristic gaps associated with water vapour, CO₂, CH4, O3 etc (Harries et al, 2001; HITRAN). The only question is how much energy is blocked by each. This cannot be calculated by hand (the number of absorption lines and the effects of pressure broadening etc. preclude that), but it can be calculated using line-by-line radiative transfer codes. The earliest calculations (reviewed by Ramanathan and Coakley, 1979) give very similar results to more modern calculations (Clough and Iacono, 1995), and demonstrate that removing the effect of CO₂ reduces the net LW absorbed by ~14%, or around 30 W/m². For some parts of the spectrum, IR can be either absorbed by CO₂ or by water vapour, and so simply removing the CO₂ gives only a minimum effect. Thus CO₂ on its own would cause an even larger absorption. In either case however, the trace gases are a significant part of what gets absorbed.
View Step 3

Step 3: The trace greenhouse gases have increased markedly due to human emissions CO₂ is up more than 30%, CH4 has more than doubled, N2O is up 15%, tropospheric O3 has also increased. New compounds such as halocarbons (CFCs, HFCs) did not exist in the pre-industrial atmosphere. All of these increases contribute to an enhanced greenhouse effect.
View Step 4

Step 4: Radiative forcing is a useful diagnostic and can easily be calculated Lessons from simple toy models and experience with more sophisticated GCMs suggests that any perturbation to the TOA radiation budget from whatever source is a pretty good predictor of eventual surface temperature change. Thus if the sun were to become stronger by about 2%, the TOA radiation balance would change by 0.02×1366×0.7/4 = 4.8 W/m² (taking albedo and geometry into account) and this would be the radiative forcing (RF). An increase in greenhouse absorbers or a change in the albedo have analogous impacts on the TOA balance. However, calculation of the radiative forcing is again a job for the line-by-line codes that take into account atmospheric profiles of temperature, water vapour and aerosols. The most up-to-date calculations for the trace gases are by Myrhe et al (1998) and those are the ones used in IPCC TAR and AR4.

These calculations can be condensed into simplified fits to the data, such as the oft-used formula for CO₂: RF = 5.35 ln(CO₂/CO₂_orig) (see Table 6.2 in IPCC TAR for the others). The logarithmic form comes from the fact that some particular lines are already saturated and that the increase in forcing depends on the 'wings' (see this post for more details). Forcings for lower concentration gases (such as CFCs) are linear in concentration. The calculations in Myrhe et al use representative profiles for different latitudes, but different assumptions about clouds, their properties and the spatial heterogeneity mean that the global mean forcing is uncertain by about 10%. Thus the RF for a doubling of CO₂ is likely 3.7±0.4 W/m² - the same order of magnitude as an increase of solar forcing by 2%.

There are a couple of small twists on the radiative forcing concept. One is that CO₂ has an important role in the stratospheric radiation balance. The stratosphere reacts very quickly to changes in that balance and that changes the TOA forcing by a small but non-negligible amount. The surface response, which is much slower, therefore reacts more proportionately to the 'adjusted' forcing and this is generally what is used in lieu of the instantaneous forcing. The other wrinkle is depending slightly on the spatial distribution of forcing agents, different feedbacks and processes might come into play and thus an equivalent forcing from two different sources might not give the same response. The factor that quantifies this effect is called the 'efficacy' of the forcing, which for the most part is reasonably close to one, and so doesn't change the zeroth-order picture (Hansen et al, 2005). This means that climate forcings can be simply added to approximate the net effect.

The total forcing from the trace greenhouse gases mentioned in Step 3, is currently about 2.5 W/m², and the net forcing (including cooling impacts of aerosols and natural changes) is 1.6±1.0 W/m² since the pre-industrial. Most of the uncertainty is related to aerosol effects. Current growth in forcings is dominated by increasing CO₂, with potentially a small role for decreases in reflective aerosols (sulphates, particularly in the US and EU) and increases in absorbing aerosols (like soot, particularly from India and China and from biomass burning).
View Step 5

Step 5: Climate sensitivity is around 3°C for a doubling of CO₂ The climate sensitivity classically defined is the response of global mean temperature to a forcing once all the 'fast feedbacks' have occurred (atmospheric temperatures, clouds, water vapour, winds, snow, sea ice etc.), but before any of the 'slow' feedbacks have kicked in (ice sheets, vegetation, carbon cycle etc.). Given that it doesn't matter much which forcing is changing, sensitivity can be assessed from any particular period in the past where the changes in forcing are known and the corresponding equilibrium temperature change can be estimated.

As we have discussed previously, the last glacial period is a good example of a large forcing (~7 W/m² from ice sheets, greenhouse gases, dust and vegetation) giving a large temperature response (~5 °C) and implying a sensitivity of about 3°C (with substantial error bars). More formally, you can combine this estimate with others taken from the 20th century, the response to volcanoes, the last millennium, remote sensing etc. to get pretty good constraints on what the number should be. This was done by Annan and Hargreaves (2006), and they come up with, you guessed it, 3°C.
Converting the estimate for doubled CO₂ to a more useful factor gives ~0.75 °C/(W/m²).
View Step 6

Step 6: Radiative forcing x climate sensitivity is a significant number Current forcings (1.6 W/m²) × 0.75 °C/(W/m²) imply 1.2 °C that would occur at equilibrium. Because the oceans take time to warm up, we are not yet there (so far we have experienced 0.7°C), and so the remaining 0.5 °C is 'in the pipeline'. We can estimate this independently using the changes in ocean heat content over the last decade or so (roughly equal to the current radiative imbalance) of ~0.7 W/m², implying that this 'unrealised' forcing will lead to another 0.7×0.75 °C - i.e. 0.5 °C.
Additional forcings in business-as-usual scenarios range roughly from 3 to 7 W/m² and therefore additional warming (at equilibrium) would be 2 to 5 °C. That is significant.
View Step 1