Sea level is a doddle, apparently the answer is to change your fossil fuel car to electric, and pay more tax. Simples.
There are some things that are going to happen no matter what humans do. Shifting magnetic poles, volcanos, earthquakes, and sea level changes are examples. The question is about whether we are making a bad situation worse.
We are continuing to make a bad and worsening situation - without question. If we don't quit doing that, we will make the already bad situation we have just now created even more rapidly worse - also without question. The remaining "question" about that is whether the worsening is linear or exponential - or possible even "catastrophic" (in the math sense - tipping point disastrous, intuitively). Those are almost certain to remain as small and inconsequential - compared with AGW - as they have been for the past couple of hundred years. And their effects - so far trivial compared with the CO2 boost - are probably going to add to the effects of the CO2 boost in some generally small ways. It's not one or the other. It's both/and. Even a Carrington Event, a larger than average but localized meteor strike, a natural (minor) version of the methane bomb, a sudden extended and simultaneous eruption of several flood volcanos, or the like, would be (in all probability) fairly small potatoes compared with a continuation of our current CO2 boost acceleration - and would be much easier to prepare for if the much more dangerous and much more likely and much larger problem of AGW were not in our face already. If we have our conversion to distributed solar power solidly and foresightedly in place by the time of the next Carrington event, for example, it will be much easier to recover and rebuild. Meanwhile: Nothing we can measure as currently happening is natural - the CO2 boost driving the climate and geochemical changes is entirely manmade, the changes are so much larger and faster than any of the "natural" changes that the natural changes are lost in the statistical noise. We can't even tell if we are in a natural cooldown headed for the next glaciation now, or in one of those extra-long natural warm breaks between glaciations Sculptor finds more interesting than looming disaster: AGW is swamping the natural signal by more than an order of magnitude. And we haven't begun to examine the physical reality of such risks - that they normally stack, for example, rather than spacing themselves conveniently in time, allowing recovery from them one by one. The incoming Carrington or meteor strike is not timing itself to occur only after we have built a less vulnerable energy supply etc. Whatever the natural background, we'll have to handle AGW successfully - keep the basics of industrial civilization and liberal democracy, including its freedoms and relative prosperity (productive agriculture managed by independent farmers rather than centralized command, for example) for a couple of hundred years and into a stable or at least predictable equilibrium of some kind (of cycles, probably) - if we ever want to know about it. Climate science is expensive. (Not compared with climate ignorance, but that cost can be hidden easily by the perps of research demolition).
