Exxon knew that fossil fuels were influencing the climate in 1978

Even if it were true, thousands of years is barely anything on any time scale that matters. Disregarding that, we've certainly not lived through thousands of years of global anthropogenic climate change, which is what this is all about.

It's worth to remember that adaption doesn't necessarily equate survival in the way we tend to think about it, as dinosaurs adapted too.

Humanity, at least on this planet, is already doomed. The sun will eventually consume us as a natural part of its life cycle. It's a very long time until that happens, but life here will eventually end. So as we're already doomed, should we then do nothing to prevent suffering and pain until then?

It should be a rhetorical question, but apparently it isn't always.

The argument can be made quite simple: As long as we continue to have children, or accept people having children, we have chosen - as a species - to not give up on them, and their descendants.

Preserving a livable environment, and preferably much more than livable, is simply a duty springing from that fact.

There is no need for any deep philosophy, to care for the environment is - essentially - a consequence of choices already made.

These percentages represent the percent of species currently threatened with extinction. The report makes it clear that the conditions which created our current ecological collapse are accelerating:

"Human actions threaten more species with global extinction now than ever before. An average of around 25 per cent of species in assessed animal and plant groups are threatened(figure SPM.3), suggesting that around 1 million species already face extinction, many within decades, unless action is taken to reduce the intensity of drivers of biodiversity loss. Without such action there will be a further acceleration in the global rate of species extinction, which is already at least tens to hundreds of times higher than it has averaged over the past 10 million years."

The report doesn't factor in insect decline and how that will effect the rest of the foodchain (they are the words biggest pollinators). It does bring up the staggering loss of insect biomass:

"Population declines often give warning that a species’ risk of extinction is increasing. The Living Planet Index, which synthesises trends in vertebrate populations, has declined rapidly since 1970, falling by 40% for terrestrial species, 84% for freshwater species and 35% for marine species (established but incomplete){2.2.5.2.4}. Local declines of insect populations such as wild bees and butterflies have often been reported, and insect abundance has declined very rapidly in some places even without large-scale land-use change, but the global extent of such declines is not known (established but incomplete){2.2.5.2.4}. On land, wild species that are endemic (narrowly distributed) have typically seen larger-than-average changes to their habitats and shown faster-than-average declines (established but incomplete)."

Edit: also, in the future, let's refrain from the "not smart enough to understand" style arguments on HN.

So what?

Most people have no problem with that. What normal people challenge is:

1) Estimate of impact. If you breathe, you're bad for CO2 emissions. But should it matter? It's hard to imagine one should care about it.

2) the government's ability to cost effectively do something about it (that is, that ability equals exactly zero, while taxes required to pay for that theft and incompetence are higher than zero).

I agree "per capita" can be misleading, but China and India are growing faster than the US, and China is outputting more CO2 than the US.

You mean when global cooling was all the rage?