[QUESTION]: What are your views on climate change, and how did you form them?

VipulNaik

Note: Please see this post of mine for more on the project, my sources, and potential sources for bias.

I have written a couple of blog posts on my understanding of climate forecasting, climate change, and the Anthropogenic Global Warming (AGW) hypothesis (here and here). I also laid down the sources I was using to inform myself here.

I think one question that a number of readers may have had is: given my lack of knowledge (and unwillingness to undertake extensive study) of the subject, why am I investigating it at all, rather than relying on the expert consensus, as documented by the IPCC that, even if we're not sure is correct, is still the best bet humanity has for getting things right? I intend to elaborate on the reasons for taking a closer look at the matter, while still refraining from making the study of atmospheric science a full-time goal, in a future post.

Right now, I'm curious to hear how you formed your views on climate change. In particular, I'm interested in answers to questions such as these (not necessarily answers to all of them, or even to only these questions).

What are your current beliefs on climate change? Specifically, would you defer to the view that greenhouse gas forcing is the main source of long-term climate change? How long-term? Would you defer to the IPCC range for climate sensitivity estimates?
What were your beliefs on climate change when you first came across the subject, and how did your views evolve (if at all) on further reading (if you did any)? (Obviously, your initial views wouldn't have included beliefs about terms like "greenhouse gas forcing" or "climate sensitivity").
What are some surprising things you learned when reading up about climate change that led you to question your beliefs (regardless of whether you changed them)? For instance, perhaps reading about Climategate caused you to critically examine your deference to expert consensus on the issue, but you eventually concluded that the expert consensus was still right.
If you read my recent posts linked above, did the posts contain information that was new to you? Did any of this information surprise you? Do you think it's valuable to carry out this sort of exercise in order to better understand the climate change debate?

Note: Please see this post of mine for more on the project, my sources, and potential sources for bias.

What are your current beliefs on climate change? Specifically, would you defer to the view that greenhouse gas forcing is the main source of long-term climate change? How long-term? Would you defer to the IPCC range for climate sensitivity estimates?
What were your beliefs on climate change when you first came across the subject, and how did your views evolve (if at all) on further reading (if you did any)? (Obviously, your initial views wouldn't have included beliefs about terms like "greenhouse gas forcing" or "climate sensitivity").
What are some surprising things you learned when reading up about climate change that led you to question your beliefs (regardless of whether you changed them)? For instance, perhaps reading about Climategate caused you to critically examine your deference to expert consensus on the issue, but you eventually concluded that the expert consensus was still right.
If you read my recent posts linked above, did the posts contain information that was new to you? Did any of this information surprise you? Do you think it's valuable to carry out this sort of exercise in order to better understand the climate change debate?

I would probably get a "sceptic" label stuck onto me.

Global warming is not a single yes/no issue (even though a lot of mindkilled people like to pretend it is). Roughly I think it breaks down into five major questions:

Has Earth been warming up during the last several decades?
To what extent the warming is caused by anthropogenic factors?
How will the climate change proceed in the future and how certain we are of the forecasts?
What will be the consequences of the change in climate?
What should be done about it?

The answer to the first question is clearly "yes". There is a lot of data and it is pretty unambiguous.

The answer to the second question, I think, is "some". It is not 100% and it is not 0%.

The third question is probably the one where my sceptic attitude is the most pronounced. I believe that the climate models looking several decades ahead greatly overstate their confidence in the results and a lot of them are junk. My belief is based on the impression that we don't understand long-term climate mechanisms well (and so can't model them well), on the results of the out-of-sample testing that we have so far, and on peeking inside the sausage factory via the Climategate documents (hint: it's not pretty).

The fourth question is complicated -- there obviously are both positive and negative consequences. As far as I remember it is usually held that the positive consequences (e.g. better harvests, etc.) overwhelm the negative until the about +2 degrees C rise in the temperature, but it's all very uncertain.

The fifth question, the most interesting of them all, is not in the domain of the climate scientists at all. It is essentially a social and a political question the answers to which are driven by values and trade-offs.

Overall, I feel the climate science has been hijacked by fearmongers who use the hysteria to push their agenda and/or just to get money. There is a huge publication bias and my prior for media publications on climate change is that they have zero useful information.

The fourth question is complicated -- there obviously are both positive and negative consequences. As far as I remember it is usually held that the positive consequences (e.g. better harvests, etc.) overwhelm the negative until the about +2 degrees C rise in the temperature, but it's all very uncertain.

Robin Hanson did an article which estimated this, but as far as I'm aware it's not "usually held" to be true. I've often found Hanson to be particularly incautious in his reasoning, and this is no exception. There are a lot of factors that this ... (read more)

2AlexMennen12y

Interpreted literally, this statement is obvious but useless. I expect you meant "it is something strictly between 100% and 0% and not particularly close to either one" (i.e. between 10% and 90%), which is a stronger statement, and not obvious a priori (not all trends have multiple unrelated causes). On what basis do you make that claim? [...] I have heard it claimed that there is a consensus that the effects of warming will be positive through +2 C, but the sources making that claim seem to be quite short of a consensus themselves. [...] Indeed. That doesn't answer the question, though.