"It is difficult to make predictions, especially about the future"
Niehls Bohr, Yogi Berra, and many others

Traces of our artistic capabilities should last for millions of years.. If not pristine, the form, if not function will show obvious ‘artistic ability.’

I think our collective focus should be on not allowing such a demise. If it’s inevitable, attempting to prove some were less responsible than others seems pointless. Anyone shifting their energy to yet another tribute to humanity at this time is as responsible as any for our demise..

many have been thinking along those lines like what would be a good warning sign that can last 10 000 years?
[hyperallergic.com]
there is The Long Now foundation clock
[longnow.org]
also there is the Golden Disk on Voyager (I know that one is not on Earth for future generations to see)
[voyager.jpl.nasa.gov]

I imagine it would be very difficult to decide what to choose to leave behing in a time and place so divided that we are letting this mass extinction happen. We are probably not worth it.

The Pyramids? I dunno...have you ever seen a neglected parking lot after just 2 years?

Yeah, the 6th mass extinction is likely underway and irreversible but that humanity won't survive is a bit presumptuous. We're the thin skinned cute(according to elephants) little apes that spread to all meridian of the planet. Unless theres a catastrophic events like nuclear warfare or the outbreak of a genetically engineered disease that absolutely devastates the population. The herd humanity will undergo a mass culling as climate change obstructs the ways which we produce food and the sea levels rise to submerge all our costal civilization. We'll have a precipitous drop in intelligence due to higher CO2 levels and a decline in atmospheric oxygen, but humanity will likely survive. And so will life on this planet. It's just going to undergo some massive changes, like the shift from giant lizards to a cacophony of little rat creatures. The planet, this big old rock in the third orbit around our star, is probably beyond our capabilities to actually destroy at the moment.

the earth and the sun will die anyway

We have, just check out the trash heaps !

But there is a lasting monument to humanity, one that will survive even a nuclear war.

[nypost.com]

Of course, the people (or aliens) that find this stuff will say that we produced nothing of value, but still...

How about a 2000-mile wide sign on the moon that 'reads', "Whatever you do, DO NOT use the fossil fuels"!

Mar-A-Lago?