You misunderstood: “No-one knows” refers to the supposed consensus on Global Warming. No such consensus exists: here’s where the 97% comes from:
“A 2013 paper in Environmental Research Letters reviewed 11,944 abstracts of scientific papers matching “global warming” or “global climate change”. They found 4,014 which discussed the cause of recent global warming, and of these “97.1% endorsed the consensus position that humans are causing global warming.”
Even among Climate scientists, that means that only 32.5% of papers endorsed the position that humans are causing global warming. Firstly they excluded all scientists who have not published papers on Global warming, then they excluded 8000 of those that found no obvious cause for Global Warming, then found that 97% of those who discussed what the cause might be, identified Humans as the cause. It is a flawed research method, clearly designed to get the figure they wanted.
If you want a true Scientific consensus on Global Warming, you randomly select 1000 scientists from all round the World and ask them: “Do you believe that burning of fossil fuels by humanity is causing dangerous Global Warming? Do you believe that a Climate apocalypse will wipe out a significant proportion of the human race unless urgent action is taken to reduce global Carbon dioxide emissions?” The second question is the one that matters.
I don’t have to be a scientist to have an opinion on global warming, and what to do about it, but yes, I trained as a scientist, but chose to work in IT. There is an arrogance in your own appeals to Authority (do you have credentials?), and the idea that only climate scientists are entitled to an opinion. Any well-educated citizen can read the research on AGW and come to their own conclusions.
Common sense and life experience has been known to sink many an intellectual theory. Here’s an example: “If the Maldives islands are sinking due to rising sea levels, why isn’t it rising at my coastline? It is all one global ocean after all. Most likely those islands are sinking because they have drained the aquifer under their island.” I watched a Warming Alarmist try to answer this, and could see the cognitive dissonance hit him as he realised the Maldives example of Global Warming effects was holed below the waterline, and a Sustainability Scientist had been out-thought by a fisherman.