(This is an international page in English, summarized, but the detailed discussion is in French at http://www.kristofmeunier.fr/antrop0.htm).

Greta Thunberg, famous environmental activist, said to the President of the USA something as "I am not requiring you to believe in me but to believe in scientists!" But - in my work, which was scientist - the bosses were liars, hiding their faults, eliminating their shocked subordinates (like me), they only cared about big money (profits or budgets). So, they are absolutely not trustworthy people. However, in the very serious case of this anthropogenic CO2 cause of global warming, have they done the right thing to establish the scientific evidence they claim?

Not at all. I will show it, by pure logic and mathematics, far from the power games between powerful dominants.

The principle of this proof (with so-called probability > 95%) is that two models were compared: the natural model (volcanoes, sun, etc.) and the anthropogenic model (human CO2); taking into account the observed evolution, it is estimated at more than 95% that it is the anthropogenic model that causes the present evolution of the climate (and not the natural model). BUT this probability is not at all absolute, only relative:

- is (implicitly) set at zero the probability of another model (God, dreamer dreaming this world, advanced aliens, etc.), without any proof, a simple arbitrary decision without any power of conviction;

- is (implicitly) fixed at zero the probability that the natural model is false, our current knowledge being very incomplete, it is a very doubtful decision, the history of sciences invalidating by experience (therefore scientifically) the scientism hypothesis (according to which current science is telling the true, all the true, nothing but the true).

In short, downstream of certain partisan choices (very questionable in principle, although this is perceived by few people), the probability of an anthropogenic cause is > 95% but honestly, taking everything into account, it is quantified between 0% and 100 %: absolutely nothing has been demonstrated (objectively).

Mathematically, in conditional probabilities, the probability of the first hypothesis is a multiplier. If we set it at 100%, we assert with certainty and alleged proof, but if we understand that it is 0 to 100%, this 0% to 100% is also the final probability, immensely doubtful and not worth proof at all. A huge scam was committed there, involving trillions of dollars. It would have been better to think honestly.

----- Addition 2021/11/05th ; self critics to my text

Nobody sent me a comment, like if nobody was interested, and this is too bad, as what I said may be the most important thing brought to science in the 21st century till now (or during the years 1981-2021).

So I can bring disapproval arguments myself:

1/ When I said that the hypothesis probability 0% to 100% has a consequence that the complete probability is 0% to 100%, this may be surprising, as “> 95%” times “0 to 100%” does not give "0 to 100%” but "0% to >95%”, I would have been a little wrong. Anyway, this calculation itself is partly wrong, incomplete. The basis of conditional probabilities is p(A and B) = p(B) times p(A knowing B) which leads to the Bayes theorem and its writing p(A)=p(B) times p(A/B) divided by p(B/A). And dividing 96% by 0.0001% for instance gives more than 100%, meaningless thus truncated to 100%, so the whole result is confirmed probability = between 0% and 100%.

2/ If the pope (for instance) would say : “global Earth warming comes from God, not from human-CO2”, this would probably face the answer “no, scientists have proven it comes from human CO2”. This answer is wrong: what scientists did is comparing only 2 hypothesis, refusing the pope’s 3rd hypothesis, not proving at all that it is wrong. A further scientist answer may be “yes, but we are right : it is obligatory to take into account exclusively scientific hypothesis not legends or dreams”. But this is not logical searching the truth, this is scientism, claiming (without proof) that the True belongs to present science. This is a matter of belief, not a proven thing. The scientism-believers are proud of themselves but they are not logical at all. They are blind believers in scientism, refusing to see and hear.