If they're anything like the ones I know, it depends on the particular day and particular discussion. There is no one stance on climate change, just a general contrarian theme. If the discussion leaves room for doubting warming in general, that will be done. If too much evidence for warming is presented, it'll switch to doubting human causes for it.
It's true that the more aware deniers updated their propaganda 5 to 10 years ago with the non-anthropogenic argument. But there are still a lot of less informed deniers that swallow the hardcore right-wing conspiracies whole. i.e. there is no warming, it was invented by Al Gore to take away our freedoms and establish a one world government.
Real climate has disproved all models to date. There has been no forthcoming explanation for the 15 year hiatus in warming. In other words the science underlying climate is far from known. As Feynman reminds us “It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.”. Thus we have to push on and cannot advise politicians.
Since 1979 the IPCC report has published a best estimate for the climate sensitivity. Its latest report says "No best estimate for equilibrium climate sensitivity can now be given because of a lack of agreement on values across assessed lines of evidence and studies.".
It is not a question of denying or conspiring. It's a matter of discovering the science behind our climate. Let's do it without the silly rhetoric.
By the way, if you believe the very worst prediction (proposed on the basis of failed models) then you will be interested in this link which asks what the cost of 'doing something' is. http://topher.com.au/50-to-1-video-project/
You'll note that the article carefully doesn't link to actual data showing the amount of heat that has actually been "trapped". (No, the IPCC report is not "data". I'm talking about actual data sets that are archived on publicly available servers with cryptographic signatures to ensure that it's complete and intact. You know, the sort of thing that is routine when you're downloading a piece of code, but which the climate science community has decided is much too difficult for data on which they want to hang the fate of the planet.)
Reading between the lines, their numbers for "trapped heat" are based on computer models, not on actual data; what they're basically saying is "the only data we have doesn't show the heat, but our models say it should be there, so we assume it went into the oceans".
I refuse to believe it without checking it, yes. (I noted somewhere upthread that there was a link to a GRL paper that might shed more light on the details in this particular case.) I take the same attitude when I read a claim about physics. I don't accept arguments from authority, and that's what "actual scientists are saying it" is. Actual scientists can be wrong. So can I, but that doesn't mean they get a free pass.
That's because they carefully picked 1997 as the starting year. What does the trendline look like if you pick other starting years?
More generally, why do we assume that a linear trendline is the appropriate way to analyze this data? Has anyone actually done an analysis that doesn't start from that assumption?
Thanks for the links. I at least see why the second graph had to pick 1880 as the starting point, since that's as far back as the instrumental record it used went. And at least it considered the possibility of a non-linear fit.
However, the curve fitting is still subject to error, because you don't have the trend before 1880, at least not in this dataset. What if the temps around 1880 were anomalously warm compared to, say, 1800? (Which we have reason to believe they were.) Then the actual trendline from 1800 or so might still be roughly linear.
But more importantly, 1880 is still an arbitrary starting point; any starting point is arbitrary unless you know you have the entire dataset, which we obviously don't. If the actual trend is, say, a sine wave with a period of roughly 800 to 1000 years, with the last peak being around 1000 - 1200 AD and the last trough being around 1600 - 1700 AD, what we're seeing now could just be the approach to the next peak.
I note that the article links to a GRL paper, which I'll have to read; its abstract doesn't make it quite clear what is actual data and what is extrapolated from models.
Top graph is slope of a linear trend line for the 15 years prior to each indicated year. Bottom graph is the underlying temperature data.
For 30 of the 15-year blocks the trend was negative; for 88 the trend was positive. The last year in which there was a linear cooling trend for the 15 years prior was 1977.
You could, but to be intellectually honest, you could only use that argument if you yourself would be convinced that no shrinking of the sea ice was evidence against global warming.
Belief in global warming can really only come down to belief in the experts, especially the IPCC. My understanding is that the most important evidence is global temperature trends. This is (and should be) analyzed very critically since the data is very complex and suffers from many issues. However it seems that the debate has already been won.
Belief in global warming can really only come down to belief in the experts, especially the IPCC.
Let's transfer this claim to another domain: "Belief in how to best organize our economy for prosperity can only come down to belief in the experts, particularly Wall Street investment bankers." Does it still seem reasonable? (And, btw, I suspect you may not have meant that you think belief in the experts is a good thing; if so, I'm giving another reason for not thinking it is.)
Also, it's easy for people to believe in experts that say things they want to hear; not so easy to believe in experts who say things they don't want to hear. How well are the experts in biology doing in convincing creationists to accept the theory of evolution? (Which, by the way, is much better supported scientifically than any theory about how the climate works.)
The plain fact is that you can't trust experts. You can't trust anyone. You also can't verify every single fact for yourself. There is no magic formula that will guarantee that we can get the right answers.
There may not even be any right answers. With regard to climate change, even if we accept for the sake of argument some particular set of predictions about how the climate will change, there will still be plenty of disagreements about whether that change is good or bad. China and India don't seem to care much that they are pumping CO2 into the atmosphere by building new coal-fired power plants like gangbusters. If we in the US decide to emasculate our economy in order to "prevent" global warming, all we may end up doing is making ourselves into a much poorer country while China prospers.
Experts in climate change are not obviously biased in the same way as investment bankers might be. They do not profit directly from the outcome of their recommendations, and they are in principle paid by the government to be objective.
That said, any set of beliefs can be self-reinforcing, and I was initially skeptical of global warming because there are strong incentives to toe the official line. I'm sure that many researchers keep on playing with their data until they get a "result" i.e. evidence for global warming. However there has also been a lot of outside scrutiny, and I also think that in spite of this bias, academia also has the ability to be self correcting.
I've never heard any argument that global warming might be good. China and India both recognize the importance of CO2 emissions. However, they claim that since their per capita emissions are lower than the West, it is the West who should reduce their emissions first. They claim that any global cap-and-trade system should be based on per-capita quotas.
Experts in climate change are not obviously biased
...square with this?
there are strong incentives to toe the official line
Doesn't that equate to bias, at least in practical terms?
They do not profit directly from the outcome of their recommendations
They most certainly do. Recommendations that there is a big problem that needs lots of analysis lead to secure jobs and political power for the scientists doing the analysis. Recommendations that "there is nothing to see here, move along" don't.
they are in principle paid by the government to be objective.
Perhaps they are, in principle, though I would argue that that isn't really true. You can't combine scientific objectivity with a political agenda, but that's exactly what government funding of science does.
academia also has the ability to be self correcting
This is certainly possible, but it's not easy, and the mechanism by which it happens is thwarted by claims of "consensus" or that "the science is settled".
I've never heard any argument that global warming might be good.
You have spewn out a lot of garbage above, and I'm not going to bother replying to all your points. The once point that was valid was
>They most certainly do. Recommendations that there is a big problem that needs lots of analysis lead to secure jobs and political power for the scientists doing the analysis. Recommendations that "there is nothing to see here, move along" don't.
This is indeed a significant bias. First, there is also an incentive for disagreeing with the mainstream since people with other political views or agendas are willing to fund it as well. I can't remember the name (google might be your friend here) but there was a group of skeptics who reanalyzed temperature data so as to better account for heat islands. They ended up confirming global warming. Second, while as a group researchers benefit from belief in global warming, an individual researcher could do very well from finding convincing evidence against global warming.
These are all reasons why in spite of this bias the conclusions of mainstream researchers are probably valid.
there is also an incentive for disagreeing with the mainstream since people with other political views or agendas are willing to fund it as well
This might be an incentive for scientists to serve other political agendas, yes. (Though it's not much of an incentive unless those other agendas have a realistic chance at political power.) But it's not an incentive for scientists to be more objective; it's only an incentive for them to be biased in a different direction.
while as a group researchers benefit from belief in global warming, an individual researcher could do very well from finding convincing evidence against global warming
I'm not sure they could; at any rate, I think it's a matter of opinion, and opinions are going to vary widely.
These are all reasons why in spite of this bias the conclusions of mainstream researchers are probably valid
No, they're not. None of these reasons have anything to do with whether the mainstream conclusions are valid. That was my original point in this subthread: to know whether or not the conclusions are valid, you have to actually look at the data and the arguments based on the data. Trying to figure it out by looking at who is biased how doesn't count.
Also, there's a bait and switch here regarding what "mainstream conclusions" we are supposed to accept. Are we supposed to accept that (1) the climate is changing? Are we supposed to accept that (2) the direction in which it is currently changing is a warming direction? Both of those claims strike me as fairly obvious.
Are we supposed to accept that (3) the IPCC's predictions of what the climate will be like in 2100 are reasonable? I don't think anybody knows enough about how the climate works to say that.
Or are we supposed to accept that (4) we have a planetary emergency and if we don't take drastic action now to keep the climate from changing, we are all doomed? I think that's wrong, and worse, it's dangerous, because acting on this recommendation will squander huge amounts of resources that could be better spent on (a) bringing more people out of poverty, and (b) making it easier for the entire world to adapt to change (climate or otherwise).
Much of the furor over climate change is people talking past each other: people who hold opinions like the ones I've just expressed on #3 and #4 are accused of denying #1 and #2, while people who are only trying to argue for #1 and #2 are accused of arguing for #3 or #4. That makes it almost impossible to have a discussion in which #1 and #2 are reasonably common ground, while #3 and #4, which are the claims that are important if you're trying to decide what to do, can be rationally disputed.
There is a difference between Amundsen a seasoned explorer making the passage in a tiny 46 ton ship by hugging the coast and dodging ice and a 75 THOUSAND ton ship making the trip.
