You can use adverbs like "absolutely" and "unreservedly" but that doesn't make your statement greater than an opinion.
Being responsible for about all of it makes it possible for us to be in control. Not being responsible would make the situation akin to being hit by a meteorite.
Some people might find that preferable, since they do not have to change, but I find it far scarier.
And when you have decades of fabricated political identity that says that we can't switch from fossil fuels and we can't change any aspect of our life that threatens the profits of a few very wealthy corporations, acknowledging these facts also means going against one's own identity.
The very same propagandists that let tobacco companies persist with false claims about smoking and cancer came back for fossil fuel companies' defense with a highly honed bag of tricks.
That's why we see massive anti-science responses in these comments, just like every media mention of climate change brings out hoards of denialist a to barrage the media outlet and scientists that show up: people perceive it as a personal attack on them and act accordingly.
Yes, that event will cause the sun to start burning helium instead, and will swell to a red giant approximately the radius of the orbit of Mars.
In about 4-5 billion years.