Don't forget that the consensus used to be that tobacco was harmless. The consensus can change from an incorrect position to the correct one.
A good history of all this is here: https://pubmed.ncbi.nlm.nih.gov/22345227/
Imagine if a company had prohibited tobacco advertising that asserted smoking was healthy. That's the parallel here.
The problem I have with this is they will almost certainly allow things that contradict the consensus. Let's say the consensus is like 2C increase in 50 years. If somebody says it will actually be 3C they would be contradicting the consensus but probably would be allowed the ad. If somebody says it will only increase 1C they would probably not be able to sell an ad.
If the scientific consensus threatens assets and income of powerful industries they run massive lobbying and ad campaigns against it and try to interfere with the scientific process itself by funding biased studies.
Pretending like the people that exaggerate the effect of climate change are a comparable issue is dishonest and not backed by facts. Classic false symmetry fallacy.
Also, the scientific consensus is conditional: If we emit like this, then that will happen. The IPCC report doesn't predict a certain amount of warming.
No? Tobacco companies themselves knew tobacco wasn't harmless. Just like oil companies have known for almost a century that humans were causing drastic climate change due to CO2.
There has been concerted funding and propaganda _against_ the science by an industry that is literally earning billions a week.
Others have already pointed out that it's always been hard to go against the consensus in science. It's supposed to be hard. The consensus became the consensus for a reason. Overthrowing it is a monumental effort that gets you into the history books.
This is not what this is about and this is not what is going on here though. In the 80s serious scientists debated man made global warming. They raised objections, and contradicted the models. Eventually all the reasonable and important objections were addressed. The debate settled. The evidence came in. We now have 30 years of observational data on top of that!
And _now_ people complain that there is no scientific debate! No one was paying attention when the debate happened! That's why you are getting the conclusion! That's why people who object are told "Yeah we covered this, check the papers." Which doesn't feel like debate but in reality just shows that the person coming in hasn't done their due diligence or isn't arguing in good faith.