2011-11-10 10:32:04Debunking the 'global warming theory can't be falsified' myth
John Cook


Someone emailed me this overnight:

I've been reading your site for some years now and think it is a great resource for countering the disinformation swirling around the climate change issue.  One argument against the theory of climate change I have come upon is that it isn't a valid science because it can't be falsified.  I've searched through the arguments but can't seem to find a good rebuttal to this argument.  There might be bits and pieces here and there in your articles which touch on this, but I'm looking for something more.  Anyway, I think it would be a good topic for a separate post.

It reminded me that at one point, we even toyed with writing a peer-reviewed review paper on this topic. We have a few links in our database both affirming and debunking the myth. We have all the material we need to debunk the myth - having expounded on all the empirical evidence for AGW ad nauseum - so perhaps it would be worthwhile tying it together into a post/rebuttal?

2011-11-10 10:55:31Funnily enough, got a second email on this topic today
John Cook


More on falsifiability - is that meme having a resurgence at the moment?

Great site. I am an intelligent and interested observer, but have no scientific training, so I appreciate your clear and simple discussions.

One thing that I have noticed is the number of deniers posting this pair of questions on blogs and in comments:
"Alarmists cannot give us
a) the specific, clear, falsifiable alarmist hypothesis
b) the supporting experiments"

Not having the training, I don't really understand what they are asking, but I have not seen a response so far and would be interested in being able to rebut the posters. If I am on the right track, I expect that the experiments they are asking for, to prove AGW, would require us to have available a number of parallel Earths, so we could conduct double blind experiments (or whatever) and I don't see that as being a sensible proposition.

Keep up the good work.

2011-11-24 20:56:43
Dikran Marsupial
Gavin Cawley

it would be a good idea to have a blog post on epistemological issues, if only so that the "we can't know anything for sure so we are justified in doing nothing" can be sent there rather than disrupting the disucssion of more interesting topics.

AGW is easily and directly falsifiable.  If we observed a century of cooling, in the presence of increasing CO2 radiative forcing and a lack of change in any other forcing that could explain the cooling, that would directly falsify AGW as AGW theory forbids long term cooling where CO2 radiative forcing is dominant.  Of course there can be quibbling about the details, but AGW is falsifiable, we just haven't seen the observations that would alsify it (yet - we can always hope)