-1=e^ipi

There is no economist consensus and never will be. It is pretty easy to obtain the title of economist (particularly if you obtain that title via the political science route and just make stuff up). Too many economists can't perform basic mathematics and the vast majority know nothing of climate science. All economics is not a science, but some parts of economics follow the scientific method. The majority of economists are not scientists, but a few economists follow the scientific method and can be described as economic scientists. Does that answer your question? Edit: actually many 'scientists' in a variety of fields do not follow the scientific method. Climate science is a good example due to its politicization.

The effect of global dimming is so small... in polar latitudes the effect of having a decently long growing season is far more relevant. This claim is absurd.

Oh look, strawman argument... again So a graphic that contains projections that expect an increase in atmospheric CO2 by a few hundred ppm and an increase in global temperatures by a few degrees by 2100 under a more extreme emission scenario doesn't support the claim that under a no or little mitigation scenario, we can expect atmospheric CO2 to rise by a few hundred ppm and global temperatures to increase by a few degrees by 2100... Yeah, you are just deluded.

...That quotation does nothing to support your claim that the Earth's geological past is not relevant beyond climate sensitivity. But again, you want to perform your distraction tactic. And yes, I'm aware that James Hansen is a climate alarmist. But at least he understands the relevance of the geological record. I was hoping you would listen to another climate alarmist. Oh well...

You think this is bad? Wait until companies start developing sex robots. Many people already have robotic or digital pets.

Of course you do. Reading scientific papers is hard. Much easier just to repeat the same dogma over and over again. And your claim that the paleoclimatology is only relevant to look at climate sensitivity is disproven by the James Hansen paper I provided since it explains its relevance in understanding polar deglaciation.

Yeah, I can agree on this. I think an upper bound is probably around 3 C (maybe 4 C on a millennial timescale with significant deglaciation). Edit: though I think the different definition of transient climate sensitivity alone is significant enough to push up the estimate in the paper on the equilibrium climate sensitivity closer to the 3 C climate sensitivity values that other papers get. Edit 2: maybe I need to do some more calculations to show this. Fair enough.

It's not just my opinion. It is fact. Please provide me with a reasonable model or reference that predicts a 2 C increase in global temperatures over pre-industrial levels as atmospheric CO2 approaches 450 ppm when NOT accounting for other GHGs. Oh, are you going to bring up that strawman attempt again? The only mistake I made in that post was I accidentally claimed that CO2 levels were being doubled from 300 ppm to 600 ppm rather than 400 ppm to 800 ppm. Of course I acknowledged the mistake right away, though it wasn't relevant in the context of that discussion because the claim I made that you were refuting was "we could expect an increase in CO2 levels by a few hundred ppm and an increase in global temperatures by a few degrees by 2100". Furthermore, because the effect of atmospheric CO2 on temperature is approximately logarithmic, the climate sensitivity is the same whether you double from 300 ppm to 600 ppm or 400 ppm to 800 ppm. But of course, rather than move on with the discussion, you want to distract, so you keep bringing up that minor mistake I made over and over again to avoid addressing my points. Okay, let's briefly look at the graphic and then some of the absurd claims you made about it: Yes, you neglect the MR12 model as an outlier because it is inconvenient for you, yet the CCSR/NIES2 model is perfectly fine... Never mind that these models were all from 2001 or earlier, a time period during which the models have significantly overestimated the warming over the past 13 years and since then most projections have been lowered. But no, let's just exclude low projections that are inconvenient to your dogma... Not only do you just exclude the most modest model, but since then you emphasize on the most extreme model. Furthermore, you are confusing climate models with emission scenarios. The announcement of the 2012 emissions level affects the expectation of the emission scenario. However, that projection with the 5 °C increase is based on a specific climate model with the same emission scenario as the other 8 climate models in the graph. Changing the emission scenario does not some how make more extreme climate models more valid, that's just insane. And yes, the A2 scenario is a more extreme emission scenario that basically resembles what will happen under no mitigation policy: http://www.ipcc.ch/ipccreports/sres/emission/index.php?idp=98 "4.4.2.2. A2 Scenarios The A2 marker scenario (A2-ASF) was developed using ASF (see Appendix IV), an integrated set of modeling tools that was also used to generate the first and the second sets of IPCC emission scenarios (SA90 and IS92). Overall, the A2-ASF quantification is based on the following assumptions (Sankovski et al., 2000): Relatively slow demographic transition and relatively slow convergence in regional fertility patterns. Relatively slow convergence in inter-regional GDP per capita differences. Relatively slow end-use and supply-side energy efficiency improvements (compared to other storylines). Delayed development of renewable energy. No barriers to the use of nuclear energy. Additional scenario quantifications of A2 were developed using the AIM (A2-AIM)9 , IMAGE (A2-IMAGE)10, MESSAGE (A2-MESSAGE), and MiniCAM (A2-MiniCAM)11 models. An alternative interpretation of the A2 scenario storyline in the form of a "delayed development" or "transitional" scenario between the A2 and A1 scenario families was developed by the MiniCAM modeling team (A2- A1-MiniCAM)." And remember that the modest claim I made that you tried to refute in the first place was that by 2100 we should expect an increase in atmospheric CO2 by a few hundred ppm and an increase in global temperatures by a few degrees Celsius.

Okay, read through the paper. I really like the approach of the author. Simple but compelling. Though it got a bit questionable here: "This can be converted to equilibrium sensitivity as follows. In IPCC (2007) Table 8.2 shows both transient and equilibrium sensitivity as computed by climate models. For the 18 cases where both are shown, the mean ratio of equilibrium to transient sensitivity is 1.81761 °C. Multiplying this by the transient forcing yields SE = 1.986 °C (1.745–2.227 °C)." I think having the ratio in °C is a typo. Anyway, I'm skeptical of their methodology to calculate equilibrium sensitivity, particularly because the definition of transient sensitivity of the author and of the IPCC seem to differ. Here is the definition that the IPCC uses from Wikipedia: http://en.wikipedia.org/wiki/Climate_sensitivity#Equilibrium_and_transient_climate_sensitivity "AA measure requiring shorter integrations is the transient climate response (TCR) which is defined as the average temperature response over a twenty-year period centered at CO2 doubling in a transient simulation with CO2 increasing at 1% per year.[7] The transient response is lower than the equilibrium sensitivity, due to the "inertia" of ocean heat uptake." - - - - - Another issue I have is with the following statement: "The log of an exponentially rising function (as CO2 is) is of course a straight line, so the linear anthropogenic warming signal detected by Loehle and Scafetta (2011) is in line with theory and can be viewed as essentially capturing the CO2 signal." Even if one accepts the premises that the effect of increasing CO2 is approximately logarithmic and that CO2 levels are exponential with time (which is roughly true if you use the following data and subtract a value of 285 ppm ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_annmean_mlo.txt), this does not mean that the anthropogenic warming signal will be linear with time since the pre-industrial CO2 level is non-zero. If you represent atmospheric CO2 as an exponential function of time A + B*exp(Ct), where A = 285 ppm is the pre-industrial level, the the logarithm of this is only a linear function of time in the limit where B*exp(Ct) >> A (which will give ln(A + B*exp(Ct)) ≈ A/B + ln( B ) + Ct). In the other limit where B*exp(Ct) << B one does not get a linear function (instead one obtains A + B*exp(Ct)) ≈ ln(A) + B/A*exp(Ct). To determine how relevant this approximation is, lets perform a taylor approximation of ln(A + B*exp(Ct)) around t = 0. This yields ln(A + B*exp(Ct)) ≈ ln(A+ B ) + Ct/(A/B + 1) + 0.5*(Ct)^2*(A/B)/(A/B + 1)^2 + higher order terms. Note that around t = 0, the linear approximation above is only valid if ln(A + B ) ≈ A/B + ln( B ), thus if we neglect the higher order terms, the error of the linear assumption is on the order of (A/B)*Ct/(A/B + 1) - 0.5*(Ct)^2*(A/B)/(A/B + 1)^2. The paper you provided used CO2 data that started with 315.62 ppm in 1959 and ended 54 years later with 395.68 ppm. This gives a C of 0.2261/year if we assume the linear approximation. Since the paper uses 1942 as the start year of the anthropogenic signal, if we take that data point for 1959, we get 315.62 ppm = 285 ppm + B*exp(0.2261*17) => B = (315.62 ppm - 285 ppm)/exp(0.2261*17) = 0.6557 ppm. Plugging A, B and C into the error formula and using t = 54 years (since this was the period during which the approximation was used), we get (A/B)*Ct/(A/B + 1) - 0.5*(Ct)^2*(A/B)/(A/B + 1)^2 = 12.18 - 0.17 = 12.01. Dividing this by 54 years yields 0.2241/year, which should be the error on the value of C from the linear assumption alone. Notice that the error on the value of C is nearly equal to C. This results from the fact that the linear approximation gave B = 0.6557, thus A >> B. But this contradicts the assumption of B >> A necessary for the linear approximation in the first place. So I'm unsure how to resolve this. Edit: I'm a bit tired so I'll come back to this issue tomorrow. Perhaps I made a mistake and/or am overthinking it. - - - - - A third issue I might have with this paper is it's discussion of general circulation models in the introduction: "Thus estimates of climate sensitivity that are not based on general circulation models (GCMs) would provide a check on model outputs." "Interestingly, estimates of sensitivity based on energy balance considerations and historical data consistently estimate equilibrium sensitivity near 2 °C per doubling. That is, they all give much lower sensitivity to a change in forcing than studies based on GCM response. These studies use various methods but generally depend on certain overlapping types of data, including estimates of solar forcing, greenhouse forcing, ocean heat content, historical temperature data, and Earth radiation balance estimates." The problem with most other models, specifically the models that only look at the above parameters is that they generally underestimate heat transfer between equatorial regions and polar regions. Thus they predict larger temperature gradients than what should correspond to reality. And if you have a larger temperature gradient then due to the T^4 nature of black body radiation, the Earth would be expected to emit more radiation to space due to the larger predicted temperature gradient then what should actually occur for a given global temperature. Thus these other models most likely underestimate climate sensitivity.

Whoops, wrong paper. I meant to do a different James Hansen paper. http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf

It is nonsense. You can't get a long-run 2C increase over pre-industrial levels with 450 ppm without considering other GHGs. Here you go: http://www.mapleleafweb.com/forums/topic/23149-americans-believe-climate-change-is-real-and-a-real-problem/page-16#entry932044 http://www.mapleleafweb.com/forums/topic/23149-americans-believe-climate-change-is-real-and-a-real-problem/page-18#entry932109

The Harper government has been anti-Assad since day 1 and have been blindly supporting islamist terrorist organizations in Syria. It's pretty obvious. It's pretty obvious it is anti-Assad. Either Al-Nusrah or ISIS.

I believe that the state institution known as marriage should be abolished for a number of reasons. But I get your point with respect to children having a supportive family environment.

If the deviation in temperature is small than a linear approximation is probably fine. But still, there are better proxies of past temperature than tree ring data.

Assumption of linearity with respect to what?

@ Tim, wow nice paper. I'll look at that. That is a very low estimation of climate sensitivity for both transient and equilibrium. I'll look through it, but I think ultimately the paleoclimate data of the Pleistocene is the most convincing.

The 2°C 450 ppm target is nonsense, and I'll explain that in another thread once I have everything together. Edit: Btw, Waldo, you realize by accepting 450 ppm to correspond to 2°C increase over pre-industrial levels, you are implicitly accepting a doubling of CO2 levels to correspond to a 3°C increase on the timescale of 100 years. Despite this, in the other thread you kept claiming that projections that suggested a doubling of CO2 levels from 400 ppm to 800 ppm would increase global temperatures by 4 degrees or less by 2100 were underestimations. Edit 2: Also, your claims that the 450 ppm target doesn't take into account other GHGs is complete nonsense.

Yeah, what's with all those scientists thinking the past is relevant? What with all of their paleoclimatology studies and all: http://www.columbia.edu/~jeh1/mailings/2011/20110415_EnergyImbalancePaper.pdf Certainly the basis of the 2C target has nothing to do with antarctic glaciation or anything. *sarcasm* Waldo, please provide evidence that the rate of evolutionary convergence (specifically for fundamental processes such as photosynthesis) is on the order of 2.5 million years or faster. I've certainly provided evidence to the contrary. Why do you continue to reject the scientific principle of Occam's Razor? Because it gives people more information as to exactly how low Pleistocene atmospheric CO2 and temperatures are.

Oh look, the same strawman argument... again. What is this, like the 50th time you've tried this?

You can keep making this nonsense claim over and over again. It will not make it any more true. The conditions under which life evolved on Earth is very relevant especially when trying to understand the effects on life when the Earth's climate changes due to increased CO2. Some traits can be evolved in 2.5 million years and adapt to the low CO2 and low temperature climate, but other traits, especially when it comes to basic biological mechanisms (specifically photosynthesis) take much longer (the evolution of the C4 cycle is a good example of significant adaptation). Plant life is optimized to an Earth with higher atmospheric CO2 and global temperature, and since the vast majority of life on earth ultimately depends on the ability of primary producers to photosynthesize, it is reasonable to expect life to perform better under a marginal increase to CO2 levels. No, what I said is that if you only look at the CO2 fertilization effect, it is positive until at least 1200 ppm. No, I never made such an absurd claim.

I agree with that. I just didn't want to bother with a better response. XD

So you claim that in order for something to be a pollutant, it must be harmful? Okay, can you prove that marginally increasing atmospheric CO2 is harmful to life on Earth?

Except in most of the past 600 million years there has been much more CO2 in our atmosphere. Often 10 or 20 times current levels. The Pleistocene (past 2.5 million years) has the coldest temperatures and lowest CO2 levels for the past 600 million years during which multicellular life has flourished on Earth. The low CO2 levels are the reason why recently C4 plants such as corn have been favoured in recent evolution history. Except for a few bacteria in Mono Lake in California, arsenic is poisonous to life. http://www.nature.com/news/arsenic-life-bacterium-prefers-phosphorus-after-all-1.11520 CO2 on the other hand is a gas that is essential for life on Earth. If CO2 levels were to drop to 150 ppm, most plant life on Earth would die.

That guy should have been arrested. I don't understand how this is entertaining. It is just some guy that clearly has some mental issues screaming at people.

Nonsense, I personally know many scientists that do not respect the scientific method and do not approach things with skepticism. There are even some famous examples such as Robert Milikan's Nobel Prize.