> Imagine if scientists just "believed" science and never tried to reproduce.
You're mixing up scientists-as-individuals with scientists-as-a-whole.
Scientists-as-a-whole should certainly reproduce results, both to check new claims, and to teach/learn/demonstrate old knowledge.
Scientists-as-individuals need belief, since there's no way to indivudally reproduce everything. For example, climate models rely on decades of measurements from Earth-observation satellites; if scientist shouldn't "believe", how would they go about reproducing those measurements for themselves?
Even if individual climate scientists began each of their projects by building and launching their own satellites to take decades of observations (which would lag behind existing data, in any case), how would they calibrate the instruments on those satellites (e.g. without "believing" in the zeroth law of thermodynamics)?
In principle, every individual could spend 10 years to learn the subject, then comb trough the evidence in one particular detail. That's not possible in reality.
Even climate scientists have to trust other climate scientists in details they are not experts in. Climate chemist has not checked 3D computational model and vice versa.
It is said that Thomas Young (1773 – 1829) was the last man who knew everything. He was a polymath who had studied most of human knowledge in detail.
Isn’t that the problem? Because for most people, believing in it is the only option? They don’t have the tools or the ability to either refute nor confirm it.
No, verification is not belief. You can believe in the methodologies I suppose, but that is not what is being said when people say "believe in science". They are saying "believe in the findings from people you haven't met who have credentials", which is nothing more than a nonsense appeal to authority.
If a subject is important to someone, they should try their best to understand the research and to more fully understand a claim, one would do well to research with a heavy dose of skepticism in everything, especially things that affirm their own bias.
Imagine if scientists just "believed" science and never tried to reproduce. Belief is an awfully terrible trait to have in science.