Maybe because laypeople somehow have a better idea of complexity and degrees of uncertainty that you do!
This is a highly irresponsible and anti-scientific attitude that you're portraying here.
Orbital mechanics of celestial objects are incredibly well understood, and can be predicted incredibly precisely. "Totality will be at 3:42:17 and last for 2:24 seconds" can be predicted at be verified to be exactly right. The degree of uncertainty that we have is vanishingly, vanishingly small.
Of course you want an educated populace to have a very high degree of trust in that, higher than in anything more complex or with more uncertainty!
The climate is a complex, dynamical process; predicting it with confidence requires everything from knowing about the photophysical properties of gases through to major upwellings and downwellings in ocean currents, with everything from land use predictions to carbon response of algae in between.
People should be skeptical. It's ferociously difficult to get all that right. They should demand that good evidence is presented: even if they don't have the background to understand the evidence, that it is at least there and checked by people who do understand is a reassurance.
And that is what happens with the IPCC reports. A very great deal is laid out there (especially in the WG1 reports which are less dependent on the vagueries of how humans respond to and enact various scenarios), and references therein lay out a very great deal more.
So people should trust that too, but it is absolutely wrong that they should trust it because "ooooo it's all sciiiiience!". They should trust it far more tentatively than that an eclipse will cross Australia in 2028, and to the extent that they do trust it--and the trust should be substantial--they should not trust it because "it's science" but because despite being such an incredibly difficult task people have risen to the challenge and documented extensively why the various pieces are reasonably in accord with evidence.
There is nothing about it being science that tells you that this immense effort has been made. Scientists have to constantly be on guard against trusting themselves and each other in complex areas with inadequate evidence, and they do get it wrong (e.g. "eating fat makes you fat").
People shouldn't treat climate change like it's orbital mechanics. They should treat it like it's a very complex process and demand that scientists document that they have adequately met the challenges of understanding something of that complexity. And they have and did. That's what we need to point to. Not "truuuust sciiiience". Doubt science. Ask it to show why it's right. That's the point.