Last Feb? He's been repeating this with evidence, for our sake since 1985 at least.
You not remember this:

"In 1988 Hansen made the greenhouse effect world news when he told a Senate committee, "The greenhouse effect has been detected, and it is changing our climate now.""

Where have you been? (unless your still a teenager)

Just like Richard Branson pledging to donate all his airline profits (£3Bn) to fight Global Warming. But no, your smarter than him I guess, £3Bn smarter.

You think so.

There is too much temperature related empirically accurate data and its been shown earlier in the thread many times.

Like here for instance:


Figure 3. Seasonal temperature change over the past 50 years based on local linear trends.

Is this past your 60 years?


Figure 1: (Above) Global annual surface temperature relative to 1951-1980 mean based on surface air measurements at meteorological stations and ship and satellite measurements for sea surface temperature. Error bars are estimated 2σ (95% confidence) uncertainty. (Below) Temperature anomaly for 2005 calendar year. Gray areas indicate a lack of station data within 1200km.

Here's Hansen from Jan 99:

Education Resource Materials

The Global Warming Debate
By James Hansen — January 1999

The only way to have real success in science ... is to describe the evidence very carefully without regard to the way you feel it should be. If you have a theory, you must try to explain what's good about it and what's bad about it equally. In science you learn a kind of standard integrity and honesty. — Richard Feynman

In my view, we are not doing as well as we could in the global warming debate. For one thing, we have failed to use the opportunity to help teach the public about how science research works. On the contrary, we often appear to the public to be advocates of fixed adversarial positions. Of course, we can try to blame this on the media and politicians, with their proclivities to focus on antagonistic extremes. But that doesn't really help.

The fun in science is to explore a topic from all angles and figure out how something works. To do this well, a scientist learns to be open-minded, ignoring prejudices that might be imposed by religious, political or other tendencies (Galileo being a model of excellence). Indeed, science thrives on repeated challenge of any interpretation, and there is even special pleasure in trying to find something wrong with well-accepted theory. Such challenges eventually strengthen our understanding of the subject, but it is a never-ending process as answers raise more questions to be pursued in order to further refine our knowledge.

Skepticism thus plays an essential role in scientific research, and, far from trying to silence skeptics, science invites their contributions. So too, the global warming debate benefits from traditional scientific skepticism.

I have argued in a recent book review that some "greenhouse skeptics" subvert the scientific process, ceasing to act as objective scientists, rather presenting only one side, as if they were lawyers hired to defend a particular viewpoint. But some of the topics focused on by the skeptics are recognized as legitimate research questions, and also it is fair to say that the injection of environmental, political and religious perspectives in midstream of the science research has occurred from both sides in the global warming debate.

So, what to do? Most scientists are willing to spend part of their time communicating with the public about how science works. And they should be: after all, the financial support for most research is provided ultimately by the public. But one quickly learns that such communication is not easy, at least not for many of us.

In late 1998, I was asked to debate the well-known greenhouse skeptic Dr. Patrick Michaels of the University of Virginia. I summarize here some key points in the debate, "A Public Debate on the Science of Global Warming", held at the New York Hilton, Nov. 20, 1998, and organized by the American Association for the Rhetoric of Science and Technology. A copy of my entire contribution may be downloaded as a PDF document (Note: This document is 597 kB and requires a special viewer such as the free Adobe Reader.).

I agreed to participate in this debate with Dr. Michaels after learning that he had used (or misused) a figure of mine in testimony to the United States Congress. The figure showed the first predictions made with a 3-D climate model and time-dependent climate forcings — it was a figure from a paper that we had published in the Journal of Geophysical Research in 1988 and it had been a principal basis for testimony that I gave to the United States Senate in 1988.


Fig. 1: Climate model calculations reported in Hansen et al. (1988).

The figure that we published is reproduced here as Fig. 1. It shows the simulated global mean temperature for three climate forcing scenarios. Scenario A has a fast growth rate for greenhouse gases. Scenarios B and C have a moderate growth rate for greenhouse gases until year 2000, after which greenhouse gases stop increasing in Scenario C. Scenarios B and C also included occasional large volcanic eruptions, while scenario A did not. The objective was to illustrate the broad range of possibilities in the ignorance of how forcings would actually develop. The extreme scenarios (A with fast growth and no volcanos, and C with terminated growth of greenhouse gases) were meant to bracket plausible rates of change. All of the maps of simulated climate change that I showed in my 1988 testimony were for the intermediate scenario B, because it seemed the most likely of the three scenarios.

But when Pat Michaels testified to congress in 1998 and showed our 1988 predictions (Fig. 1) he erased the curves for scenarios B and C, and showed the result only for scenario A. He then argued that, since the real world temperature had not increased as fast as this model calculation, the climate model was faulty and there was no basis for concern about climate change, specifically concluding that the Kyoto Protocol was "a useless appendage to an irrelevant treaty".

Although scientists have a right to express personal opinions related to policy issues, it seems to me that we can be of more use by focusing on the science and carrying that out with rigorous objectivity. That approach seems to be essential for the success, as well as the "fun", of scientific research.

Fig. 1 is a good case in point. We now know (Hansen et al. 1998a, 1998b) that the growth rate of greenhouse gases in the period 1988-1998 has been flat, very similar to scenarios B and C (which are nearly the same until year 2000). Thus we can compare real world temperature changes in the past decade (filled circles in Fig. 1) with model calculations for the B-C scenarios. Taking account of the fact that the real world volcano occurred in 1991, rather than 1995 as assumed in the model, it is apparent that the model did a good job of predicting global temperature change. But the period of comparison is too short and the climate change too small compared to natural variability for the comparison to provide a meaningful check on the model's sensitivity to climate forcings. With data from another decade we will be able to make a much clearer evaluation of the model.

Table 1. Key Differences with (the few) Skeptics


As the opinions in the global warming debate do not seem to be converging, it seems to me that one useful thing that can be done is to clearly delineate the fundamental differences. Then, as our scientific understanding advances over the next several years, we can achieve more convincing evaluations of the global warming issue. (Stated less generously, this is a way to pin down those who keep changing their arguments.)

Table 1 summarizes chief differences that I delineated for the sake of a discussion with Richard Lindzen, who has provided the intellectual underpinnings for the greenhouse skeptics, in October 1998. I also used this list (Table 1) as the principal fodder for my "affirmative closing argument" in the debate with Pat Michaels.

Differences 1 (reality of global warming) and 2 (climate sensitivity) are very fundamental. From my perspective, strong evidence is already accumulating that weighs heavily against the skeptics contentions that there is no significant global warming and that climate sensitivity is low. These issues will become even clearer over the next several years.

Difference 3 (water vapor feedback) is related to climate sensitivity, but is so fundamental that it deserves specific attention. The topic has resisted definitive empirical evaluation, because of the poor state of water vapor measurements and the fact that tropospheric temperature change has been small in the past 20 years. Ozone depletion, which affects upper tropospheric temperatures, has also complicated this problem. This situation will change if, as I would anticipate, ozone depletion flattens and global temperature continues to rise.

Difference 4 has an academic flavor, and is perhaps not worth special efforts. But it illustrates a lack of understanding of the basic greenhouse mechanism by Lindzen.

Difference 5 is fundamental because substantial efforts to curb global warming may require that climate change first be apparent to people. If our assessments are right, we are in fact on the verge of warming being noticeable to the perceptive person-in-the-street. (See related material Global Temperature Trends: 1998 summation and the Commen Sense Climate Index.)

Difference 6, concerning the planetary "disequilibrium" (imbalance between incoming and outgoing radiation) is the most fundamental measure of the state of the anthropogenic greenhouse effect. The disequilibrium should exist if climate sensitivity is as high (and thus the ocean thermal response time so long) as we estimate, and if increasing greenhouse gases are the dominant climate forcing mechanism. We have presented evidence (Hansen et al. 1997) of a disequilibrium of at least 0.5 W/m2. This imbalance is the basis by which we could predict that record global temperatures would occur within a few years, that the 1990s would be warmer than the 1980s, and that the first decade of next century will be warmer than the 1990s, despite the existence of natural climate variability. I do not know of a reference where Lindzen specifically addresses planetary radiation imbalance, but his positions regarding climate sensitivity and the ocean response time clearly imply a smaller, negligible imbalance.

The important point is that the planetary radiation imbalance is measurable, via the ocean temperature, because the only place this excess energy can go is into the ocean and, probably to a less extent, into the melting of ice. If our estimates are approximately right, this heat storage should not escape detection during the next several years.

In summary, all of these issues are ones that the scientific community potentially can make progress on in the near future, if they receive appropriate attention. The real global warming debate, in the sense of traditional science, can be resolved to a large extent in a reasonable time.

--------------

Something else to see:
Hansen, J., I. Fung, A. Lacis, D. Rind, S. Lebedeff, R. Ruedy, G. Russell, and P. Stone 1988. Global climate changes as forecast by Goddard Institute for Space Studies three-dimensional model. J. Geophys. Res. 93, 9341-9364.
http://pubs.giss.nasa.gov/abstracts/1988/Hansen_etal.html

Obviously I see no sign of those that used to argue (for whatever political purpose) partially against the generally accepted and thoroughly reliable scientific experts of the world since the onset of this year and its magnificent findings and compelling data. They could only argue on one leg behind the curtain due to their being a weakness in our then current ability and records to provide empirical evidence we now have and are definitely acquiring daily - much more to support all our contentions and previous analysis based on the most scrupulous research techniques. Scientists accepting and realizing GW were right in EVERY piece of evidence and analysis.
I wonder what research evidence they the few skeptics can present against every one of these daily positively assuring research results we produce. I must admit, none whatsoever so far.

It boils down to what we know rather than what we don't. As far as its cautiously predicted by the year 2050-only as far in the future, after all, as 1950 is in the past-the global temperature could be 3 degrees Fahrenheit warmer than it is now. It has not been that hot for 400,000 years, a time well before modern humans evolved. By 2075 a 5-degree jump would make the planet its hottest in 4 million years, and by the end of the coming century the earth could be as hot as it was 65 million years ago, when the dinosaurs disappeared.

Rapid heating on this scale will change the very face of the planet and cause chaos for the global environment, the economy, and politics. Glaciers will melt, and as seas heat and expand, the ocean will rise, drowning low-lying island nations and coastlines. Say sayonara to the Maldives, the Pacific atolls, Bangladesh, the Nile River delta, and much of the East and Gulf coasts of the United States. Tens of millions of people will be forced to move, and move again, in a kind of endless caravan, bearing conflict and disease. Adapted to specific climate zones, plants and animals will be hard pressed to move north; climate zones could shift 400 miles north by the end of the next century-far faster than trees and other plants spread after the retreat of the last glacier-and many species will become extinct. Old forests will burn, farmland will succumb to drought, and floods will increase.

As Wallace Broecker, a geochemist at Columbia University's Lamont-Doherty Earth Observatory, warned in the late 1980s, "Earth's climate does not respond in a smooth and gradual way; rather, it responds in sharp jumps

It can all be broken down to this in simple language:

QUOTE

1. Observed global warming: real or measurement problem? Hansen: global warming is 0.5-0.75°C in past century, at least ~0.3°C in past 25 years. Lindzen: since about 1850 "...more likely ... 0.1±0.3°C" (MIT Tech Talk, 34, #7, 1989). 2. Climate sensitivity (equilibrium response to 2×CO2) Lindzen: ~< 1°c Hansen: 3±1°C Comments: paleoclimate data, improved climate models, and process studies may narrow uncertainties; observed climate change on decadal time scales will provide constraint if climate forcings are measured; implicit information on climate sensitivity can be extracted from observed changes in ocean heat storage. 3. Water vapor feedback Lindzen: negative, upper tropospheric water vapor decreases with global warming. Hansen: positive, upper and lower tropospheric water vapor increase with global warming. References: (these include references by Lindzen stating that, in response to global warming, water vapor will decrease at altitudes above 2-3 km). Comment: accurate observations of interannual changes (several years) and long-term changes (1-2 decades) of upper tropospheric water vapor could provide defining data. 4. CO2 contribution to the ~33°C natural greenhouse effect Lindzen: "Even if all other greenhouse gases (such as carbon dioxide and methane) were to disappear, we would still be left with over 98 percent of the current greenhouse effect." Cato Review, Spring issue, 87-98, 1992; "If all CO2 were removed from the atmosphere, water vapor and clouds would still provide almost all of the present greenhouse effect." Res. Explor. 9, 191-200, 1993. Lacis and Hansen: removing CO2, with water vapor kept fixed, would cool the Earth 5-10°C; removing CO2 and trace gases with water vapor allowed to respond would remove most of the natural greenhouse effect. 5. When will global warming and climate change be obvious? Lindzen: I personally feel that the likelihood over the next century of greenhouse warming reaching magnitudes comparable to natural variability remains small. Hansen: "With the climatological probability of a hot summer represented by two faces (say painted red) of a six-faced die, judging from our model by the 1990s three or four of the six die faces will be red. It seems to us that this is a sufficient 'loading' of the dice that it will be noticeable to the man in the street." J. Geophys. Res. 93, 9341-9364, 1988. 6. Planetary disequilibrium Hansen: Earth is out of radiative equilibrium with space by at least approximately 0.5 W/m2 (absorbing more energy than it emits). Comments: This is the most fundamental measure of the state of the greenhouse effect. Because the disequilibrium is a product of the long response time of the climate system, which in turn is a strong function of climate sensitivity, confirmation of the disequilibrium provides information on climate sensitivity and an indication of how much additional global warming is "in the pipeline" due to gases already added to the atmosphere. This disequilibrium could be measured as the sum of the rate of heat storage in the ocean plus the net energy going into the melting of ice. Existing technology, including very precise measurements of ocean and ice sheet topography, could provide this information.