You can reach a point on basic concepts where the sheer weight of the evidence tells you that the idea is right, even though some details are left to be worked out. Science is an iterative process — we strive to be less wrong than the iteration before, and we work out details that are out on the edges of what we’ve been able to investigate. Sometimes, as in the case of quantum mechanics and relativity, those edges reveal a whole new set of behaviors, but as interesting and useful as those paradigm shifts have been, one needs to recognize that the physics that came before is still valid over a wide range of sizes and speeds. Classical treatments still work well for macroscopic objects and speeds not a large fraction of c.
Similarly, we know that the planet is heating up and we know that humans have a significant effect on this. That’s settled, despite the sturm und drang of the denialists. What’s not settled is a matter of precision of the individual contributions and effects. Germ theory is settled science, even as we learn more and more about the details of microorganisms and how they behave. And so on for gravitation, the Big Bang, and evolution.