My understanding is we have a few billion years before we need to worry about that.
A (slightly) more immediate worry is the Sun's luminosity increasing about 1% every 100 million years. That will eventually push Earth's climate into a regime that will probably be incompatible with human life.
D'ya think we just recycled and keep coming back SP? If so we would have something to worry about futurely! Thank you for your reply and the link! :) Gonna ask.
I don't necessarily agree. Once the effects of anthropogenic climate change become sufficiently large. all sorts of social chaos and war will break out, killing millions of people, reducing demand for carbon-based fuels, and sinking lots of carbon in buried corpses.
We have seen similar periods of global cooling due to mass human death after the Black Plague and WW II.
So the best hope for humanity is a world-wide (Non-nuclear ) disaster that wipes out a large percentage of the population? The global cooling caused by human deaths is a stretch. The mass of the current human population is miniscule compared to that of our atmosphere. Fossil fuel burning per capita has definitely increased, though.
Other factors which cause carbon sinking because of mass human death:
--Explosions and fires from warfare spew dust and soot into the atmosphere, reducing solar radiation transmitted through the atmosphere (similar to volcanic eruptions)
--Fewer people means less land with human habitation. Vegetation (i.e. weeds) tend to take over unoccupied land fairly quickly, pulling more carbon out of the air and turning into cellulose.
I don't know if it's the "best hope for humanity", but it is the scenario I think most likely. If I could bet upon it, I would bet upon refugees fleeing low-lying countries (e.g. Bangladesh) being fired upon by the military of destination countries, bringing about escalating war and probably a nuclear exchange in the Indian subcontinent or Southeast Asia.
The main carbon dioxide sink of the planet is the ocean and its lifeforms...mainly algae. Gases dissolve more readily in cold than warm waters. Ocean temperature increase reduces the solution of carbon dioxide. Bad news. All of the factors you mentioned are true, but there are so many variables that a one shot solution is not possible without wiping out half the human population.
SaltyPebble 