Hard to attribute that to defamation. Not saying there's no causal link, but funding can be fickle and this could happen if climate change science ever becomes unsexy or saturated.

Hard to claim people like this aren’t in it for the money/as just a job when they then sue for damages in court when attacked for their research. It might not have been a nice way to say it, but scientific discourse is about pushing hard to guarantee accuracy and if anyone believes the data was cherry picked or inaccurate they should have every right to say so. What precedent would it set if you could sue scientific skeptics for damages, what does this accomplish except for disincentivizing healthy scientific discourse?