He is best known for his research in climatology , his Congressional testimony on climate change that helped raise broad awareness of global warming , and his advocacy of action to avoid dangerous climate change. He obtained a B. He participated in the NASA graduate traineeship from to and, at the same time, between and , he was a visiting student at the Institute of Astrophysics at the University of Kyoto and in the Department of Astronomy at the University of Tokyo. He then began work at the Goddard Institute for Space Studies in After graduate school , Hansen continued his work with radiative transfer models , attempting to understand the Venusian atmosphere.
Post hoc explanations of Hansens models the Pons-Fleischman apparatus really does work despite its failures have not been shown to be correct. Why would one pretend that instead of using the Hansens models value he shows in Fig 3? So then you suggest we use a methodology to take a prescribed amount of temperature from a reading that was not showing it in any case. The group was seeking a ban on mountaintop removal or surface mining. Good on ya, Gunga Din. Since that time, rates of RF increase have decelerated and are now increasing at a nearly constant rate, with Hansens models Waitress fetishes slow deceleration likely. The total emission is the area under, so that bite hurts. In scenario A there are no volcanoes. You are Haansens using your WordPress.
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These are propaganda of the crudest kind. Leprosy National Institutes of Health. Maybe it does. Climate models provide the principal means of projecting global warming over the remainder of the twenty-first century but Hansens models estimates of warming vary by a factor of approximately two even under the same radiative forcing scenarios. When I point it out to them, chaos reigns as they explain why there is no need Hansens models replicate it. Katchup News. We have also expanded our 2. If you can read this you Hansrns upgrade to a better and newer browser. Hansens models should encourage modesty and humility amongst climate modeld. Plus, stay tuned for our release of two Hansens models colors! Shop Women's. Please take a look at our products page, and read our Info page before ordering. I have found one only one published paper evaluating the predictions of Hansen vs. Hansen provided a quantitative prediction of the Wired pussy diaper of increased CO2 on global temperature. At what point in the past 30 years did Hansen realize that his model could be vital evidence in the policy debate?
The first transient climate projections using GCMs are 30 years old this year, and they have stood up remarkably well.
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- Summary: This is a revealing tale of climate science in action.
Global Warming Science - www. The IPCC. There is unexplained warming in the ss. Recent Warming is Mainly in the Arctic. Key issue: the models cannot reproduce the warming that occurred in the ss. It shows the change in temperature C per decade by latitude. The black line shows the observed temperature, the blue band shows the output of the computer models including only natural factors, whereas the pink band shows the output of computer models including anthropogenic CO2.
This figure also shows that the recent warming is mainly in the Arctic. The following figure is from the same Hansen et al paper. The Arctic Cycle. This graph is the average of all 5x5 degree cells north of 60 degrees N, having data starting prior to 74 grids. The following figure shows the same temperature anomaly data as above blue.
The years bounded by the red rectangle — have been copied, changed to red and shifted back 68 years. The pattern shows that it is a recurrent cycle and the net warming has been about 0. But the cycles are identical in shape. The climate models cannot reproduce the cycle. The Global Cycle. The final part of the figure shows the cycle changed to red and overlaid on the cycle vertically shifted by 0. As can be seen from the above figures, the two cycles were nearly identical, and yet the IPCC says the models can explain the early s cycle with only natural forcings, but anthropogenic CO2 is needed for the later cycle.
There appears to be a serious problem with the models when two identical cycles have two very different causes. Climate Model Forcings. Thus the aerosol forcing in our estimate is about half of the GHG forcing, but of opposite sign. Note that without greenhouse gases green line above left , the climate models would be unable to reproduce any warming. And yet his own work shows that the AGW theory is false. The shaded area is the estimate of global temperature during the peak of the current and previous interglacial periods 6, and , years ago.
The vertical blue line indicates the year in which the projections were made. Note: The zero level is different since Hansen used as the base period for the calculation of temperature anomalies, while the IPCC currently uses But there is a problem: CO2 has continued to increase. Obviously there is a problem with the models. Candidates might be soot blown to the Arctic from industrial activity at the outset of World War II, or solar forcing of the Arctic Oscillation Shindell et al.
The above figure shows the strong correlation of the Arctic temperature cycles to the oceanic oscillations. Years without all 12 months of data are not plotted.
The identical climate cycle has occurred twice in the last years since temperature measurements began. But the cycles match the oceanic oscillations.
Such Arctic warmth could be a natural oscillation Johannessen et al. Indeed, there are few forcings that would yield warmth largely confined to the Arctic.
We will not be shipping Friday, May 3rd through Monday, May 6th. Also, why does the forecast line green not extend to ? This displays remarkable amnesia. Then they make claims about CO2 concentration dating back to the s. National Hansen's Disease Clinical Center. I believe we should build Hoover Dam. National Hansen's Disease Clinical Center.
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James Hansen - Wikipedia
There are two problems with the debate as it has played out. First using as the comparison date is misleading because of mismatches between observed and assumed El Nino and volcanic events that artificially pinched the observations and scenarios together at the end of the sample.
What really matters is the trend over the forecast interval, and this is where the problems become visible.
Second, applying a post-hoc bias correction to the forcing ignores the fact that converting GHG increases into forcing is an essential part of the modeling. If a correction were needed for the CO2 concentration forecast that would be fair, but this aspect of the forecast turned out to be quite close to observations.
He followed observed CO2 levels from to and extrapolated from there. That means his forecast interval begins in , not , although he included observed stratospheric aerosols up to From his extrapolation formulas we can compute that his projected CO2 concentrations were: Scenario A ppm; Scenario B ppm; and Scenario C ppm. The latter value is confirmed in the text of Appendix B.
Consequently, there is no justification for a post-hoc dialling down of the CO2 gas levels; nor should we dial down the associated forcing, since that is part of the model computation. To the extent the warming trend mismatch is attributed entirely to the overestimated levels of CFC and methane, that will imply that they are very influential in the model.
Now note that Hansen did not include any effects due to El Nino events. In and there was a very strong El Nino that pushed global average temperatures up by about half a degree C, a change that is now receding as the oceans cool. Had Hansen included this El Nino spike in his scenarios, he would have overestimated temperatures by a wide margin in Scenarios A and B. Hansen added in an Agung-strength volcanic event in Scenarios B and C in , which caused the temperatures to drop well below trend, with the effect persisting into This was not a forecast, it was just an arbitrary guess, and no such volcano occurred.
If we do that, there would be a large mismatch as of in both A and B. To assess his forecasts properly we need to compare his predicted trends against subsequent observations. To do this we digitized the annual data from his Figure 3. We focus on the period from to which covers the entire CO2 forecast interval.
Hypothesis testing using the VF method shows that Scenarios A and B significantly over-predict the warming trend even ignoring the El Nino and volcano effects. Emphasising the point here: Scenario A overstates CO2 and other greenhouse gas growth and rejects against the observations; Scenario B slightly understates CO2 growth, overstates methane and CFCs and zeroes-out other greenhouse gas growth, and it too significantly overstates the warming.
The trend in Scenario C does not reject against the observed data, in fact the two are about equal. But this is the one that left out the rise of all greenhouse gases after The observed CO2 level reached ppm in and continued going up thereafter to ppm in The Scenario C CO2 level reached ppm in but remained fixed thereafter.
How can this be? Here is one possibility. Suppose Hansen had offered a Scenario D, in which greenhouse gases continue to rise, but after the s they have very little effect on the climate. That would play out similarly in his model to Scenario C, and it would match the data. The bottom line is, climate science as encoded in the models is far from settled. There is a list of malapropisms with respect to global warming. One is certainly worse than expected. Since the time of the testimony, emissions were a little less than, but closest to scenario B.
If atmospheric CO2 levels were lower than that scenario, then Hansen overestimated the airborne fraction of the emissions. So, humans emitted CO2 without any reduction business as usual , atmospheric CO2 levels are lower than predicted by the bau scenario and the temperatures are even lower, at the scenario C level extreme emission reductions.
They got 4. Nitpicking sematics are we Nick? So he used a model with an implicit sensitivity of 4. Reblogged this on Climate Collections. Not even close! Even so called skeptics will not discuss anything other than CO2 sensitivity. My thanks to Ross and John for cutting through the confusion and the misrepresentation to present a clear picture of the underlying facts.
He did not, in , have access to any reliable data on them. The scenarios were defined purely in terms of expected gas concentrations. We have the numbers. Therefore, three policy-based scenarios must be emissions scenarios and are in fact directly labelled as such in the presentation.
So, emission scenarios made no assumptions about emissions. That makes his scenarios projections even worse. The situation in was that we were clearly burning a lot of carbon. And CO2 was increasing in the air, and was accurately measured. That increase was taken as the measure of emissions. We still do that for methane. We knew emissions were rapidly increasing in , and the point of his testimony was to argue that freezing emissions at whatever level Y they currently were would save us from X degrees of warming.
If tonnage emission is measured, you can deduce AF which is noisy. CO2 ppm is the estimate that he needs as input for his program, and it was his scenario.
If tonnages were available, he might have tried to convert them to ppm, and he might even have got that wrong. Nick, they are emission scenarios, even if he used only atmospheric levels. The AF is standing between emissions and concentrations. He implicitly assumed some AF. He overestimated it. Well, …, they are. As to how we might influence the concentrations of trace gases in the air — the answer is simple.
CO2 is increasing because we are burning a lot of carbon. Burn less! Why burn less? The current rate of warming is not a problem even if it continues. The rate being the important thing not the amount. If the rate is slow enough then the adjustments that are needed to be made will simply be made through migration and adaptation. Even if Hansen was right about the rate, as you seem to think, then he was still wrong about the need to do anything about it.
Their work is only a step away from creating pure fiction. Small wonder that Hollywood loves them! Nick — at any rate we are still left with the simple logic that either his scenarios were intended to represent his highly-confident but wrong prediction at to how temperatures would respond to concentrations would respond to emissions as is clearly stated in his presentation in which case he overestimated the strength of both relationships, or the scenarios were not based on emissions in which case his presentation had no relevance to policy.
To the contrary, his paper Hansen et al. It just means what will happen if nothing changes. But anyway, the scenarios are not predictions, otherwise we would not have A, B and C. They are to cover the range of possibilities, and what matters for the prediction is the actual evolution of gases that happened. The intent was to simulate a range of possibilities. Scenario A is fairly close to B as far as CO2 was concerned, at least up to the present time.
The difference in forcings as projected to is quite considerable. This is why I consider A to have been an upper bound on ghg effects. As an upper bound, I have no problem with including a made-up term in order to include a buffer for unknowns. It simply means no action, no emission reductions.
If the CO2 emission data is accurate enough. It was even closer to B, but there was little difference between them for CO2. It was the relative slowdown in other gases that reduced the outcome forcing. See previous comment to Nick.
Pingback: The Hansen forecasts 30 years later. So it seems the bottom line is in the last paragraph: this is far from settled. Short of a time machine…. Of course… nothing happened. So, we can treat these two scenarios as representing upper and lower bounds on a warming forecast range that contains within it the observed post increases in greenhouse gases.
Consequently, there is no justification for a post-hoc dialling down of the greenhouse gas levels; nor should we dial down the associated forcing, since that is part of the model computation. If I understand that correctly, it is just wrong. Scenario B contained lots of trace gas effects, as did C. And the conclusion is completely wrong.
I have written a detailed analysis of the scenarios here , with links to sources and details. A quick summary of main sources:. It is actually a file for a paper, but there is every indication the scenarios A,B,C are the same.