We are burning ourselves to death

"Our spread over the earth was fuelled by reducing the higher species of vegetation to charcoal, by incessantly burning whatever would burn. Combustion is the hidden principle behind every artefact we create. The making of a fish hook, manufacture of a china cup, or production of a television programme, all depend on the same process of combustion. Like our bodies and like our desires, the machines we have devised are possessed of a heart which is slowly reduced to embers."
-WG Sebald, "The Rings of Saturn"

This is precisely why our civilization is inextricably wedded to fossil fuels - they're the easiest thing on the planet to burn, and easy to transport to wherever we want to burn them. More broadly, it's why humanity is in a carbon trap" Our continued survival depends on the very thing that is killing us.

For an intelligent species living on a high-carbon planet with an oxygen atmosphere, burning stored carbon and using the released energy of combustion is easy and obvious. It would probably be done fairly early in the life of the species, well before they accumulate enough scientific knowledge to detect the long-term planetary danger of the carbon dioxide exhaust gases. In our case we have been burning carbon to use its stored energy for hundreds of thousands of years. But we figured out the dangers of CO2 (global warming, climate destabilization and ocean acidification) less than a hundred years ago.

By the time the danger is realized, the species will be carbon-dependent - locked into the burning of carbon for energy - trapped in a vicious spiral of thermodynamically-driven self-organization, energy-dependent maintenance of existing physical and social structures, increasing energy dependence, increasing CO₂ production - and increasing planetary heating from the greenhouse effect.

If there is enough carbon available (as there seems to be here on Earth), the species will become technologically advanced, will send out signals for a short while and will then go extinct due to an inability to adapt to the planet's changing climate. The species will not climb out of its gravity well and fly to the stars, because the energy required will all be soaked up in its own growth, and extinction will happen well before it gets to the "Dyson Sphere" stage of development.

To my mind, this is a highly probable explanation for Fermi's Paradox, aka 'Where is everybody?" Clever species in an environment suitable for developing technology (i.e. one with a lot of stored carbon and an oxygen atmosphere) have a very high chance of burning themselves into collapse in short order.