The Non-Henny Penny's don't really have to spend money to prove anything...nature is proving the point that they are much closer to being proven correct just as fast as the chicken little's theories are being proven to be mostly bunk...
We Told You So...!
The problem with that is, it's not true. Nature is proving that the effects of greenhouse gases cannot be escaped. If you care to read about the actual work being done, as opposed to reading twisted commentary about the results of that work, you will see a much different picture.
Scientist may differ on the degree of change, or the weight of the various mechanism of change, or the accuracy of a model, but they aren't by any means saying there is no change being caused by humans. And, for all practical purposes, they universally agree more is coming.
The thrust of much of the current research is not "is climate change caused by humans", it is now focusing on how to better predict and deal with the outcome of that change in areas such as agriculture, city planning, habitat preservation and forestry. In other words, global warming induced climate change is a given for those researchers and the commercial interests who fund much of their work.
Deniers have every opportunity to do the basic research that would support their claims. The Koch Bros. and others would gladly pay for it IF they thought there was anything to be found in the science. They aren't doing that because they aren't stupid. They are using the old tactic of when the science is not on your side, attack the science and scientists, and crank up the PR machine to full volume.
Attacking other people's work, and doing your own work that others may comment upon, are two different things entirely. Do you think big tobacco really cared that they were wrong and lied? They may have found or paid some goof ball to say tobacco is good for you, but they never produced any research that backed that up. They were managing a strategic retreat to prolong profit as long as possible. Same thing the fossil fuel people are doing today with climate change.