Last night I received another interesting comment from another climate change discussion board on Youtube. This one was long and detailed, including many different arguments. I will not produce the person's comments here without his or her permission, but I will introduce the person's first claim, then reproduce my responses. I am sorry that it is a little bit rambling, but I expect that on the whole, those seeking information might find it useful. I include some commentary in square braces [ ].
Perhaps I wasted my time, but I think the discussion might be useful to other people on either side who might be open minded about the issue. I should say up front that I am not a climate alarmist. I am also not a climate change denier. I am a climate scientist with interest in this problem. I am not an expert in all aspects of the problem (as no single person can be).
The person's first complaint was that climate change science originated as guesswork:
Of course it was figured out by guess work. That's how science works. Scientists see an issue, make a guess--Then test it with evidence. That a theory starts as a guess is irrelevant in the end, because of all of the accumulated evidence and logical argument.
[My earlier comment, to which this person had responded, pointed out that a scientist who could overturn the whole concept of CO2-induced climate change would get a Nobel Prize--The person's comment suggested that this possibility was ridiculous to them. My response follows.]
Why would you suggest that my suggestion is ridiculous that someone would win a Nobel prize for overturning it? Because the amount of effort required to overturn the whole theory, including the bold and clear evidence required would be so profound that the person would clearly deserve the prize. [I should add, that I think a person making such a discovery along with the profound evidence required would almost certainly win a Nobel prize--my point is that a person could not get that far just by asserting that they think that most climate scientists are wrong--they would need to prove it beyond reasonable doubt.]
[The person then asked "how are they (the scientists) so sure..."]
No good scientist is completely sure about human-induced climate change. The reason they are "so sure" is that they see evidence for it.
[The person then asserts that scientists have changed the language, from "global warming" to "climate change".]
Your supposed conflict between "climate change" and "global warming" is a straw man. Climate change refers to the whole set of changes, whereas "global warming" is one particular aspect. People still call it global warming, but when their interest is, for example, a reduced total number of hurricanes, increased drought in some parts of the world, increased floods in other parts, reduced tornado activity (perhaps), or ocean acidification, they refer to climate change.
[The person then asserts that science has often been wrong, and changes over time.]
Of course science has often been wrong. That's how science works. People's understanding of almost all natural systems has been improving over time, with new ideas supplanting the old ones. Yet, although there were a few papers in the 1970's discussing potential for global cooling, even then, more papers were published on longterm warming. The first paper on climate change by CO2 was before 1900, by Arrhenius.
Of course the climate has always been changing. That fact in no way refutes that humans can contribute to it today.
I do agree that some people in the environmental movement have developed almost religious behavior with respect to climate change. Also, some people trumpet the very worst possible outcomes as the most likely ones (although some such outcomes may be less likely, there is still the possibility of their development).
I wrote a blog yesterday responding to an assertion similar to yours that scientists make these claims to get grant money: http://roundyeducationblog.blogspot.com/2016/04/do-most-climate-scientists-argue-that.html
[The person then discussed how he or she thinks that climate scientists are high priests in some kind of religion.]
Your comparison to religion may explain the behaviors of some environmentalists, but it cannot explain how ideas get through peer review. Peer review is a brutal process. An assertion of faith is insufficient, even if they refer to some aspect of anthropogenic climate change. [I should have noted here that many papers arguing for some particular responses in the climate system to climate change do in fact get rejected for too little evidence or poor arguments. Papers don't get accepted simply because they trumpet arguments consistent with the prevailing view.]
[The person then commented again that views of scientists have along history of changing.]
Aspects of scientists views about climate change will certainly change. For example, as evidence has accumulated, many climate scientists have concluded that the number of weak to moderate intensity tropical cyclones will actually decline with time in response to increasing CO2, and that accumulated snowfall in the Antarctic will actually increase for a while (because it is more often warm enough to snow than in the past). But your notion that the whole thing will get thrown out is quite unlikely. Increasing CO2 concentrations do, and will warm the earth. That's a fact measured in the lab: https://agwobserver.wordpress.com/2009/09/25/papers-on-laboratory-measurements-of-co2-absorption-properties/
What will almost certainly change is our understanding of how much warming will actually occur [a point that we will not be fully certain about until we measure it]. I personally don't anticipate the strongest warming amounts proposed, except perhaps in the Arctic. Negative feedbacks in the tropical regions seem too profound to me. Yet that in no way implies that no negative consequences are likely. Negative consequences are already occurring--especially in the Arctic.