What will be the most likely of causes for human extinction?

I don't mean to sound like an alarmist though one day humans will not be around.
All species on top of the food chain only stay dominant for so long.
The only question that remains is what will cause our demise.
Will it be natural selection? Will it be lack of a food source?
Could it be biological? Chemical? Nuclear? Gods wraith?
Or will a new species climb above us on the food chain?

The shark has outlasted dinosaurs as top predator and now is finding
its way into soup bowels as shark fin stew.
These prehistoric predators do play an important role
in the health of the oceans removing decaying carcasses
and reducing disease in the seas.

The dinosaurs had a good run we are still trying to pinpoint the exact cause
as to why the dinosaurs disappeared as the strongest theory to come out is a meteor hit earth with such great force that particles from the collision changed the temperature of the planet and stopped sunlight and caused most vegetation to die and the lack of food source combined with a shift in temperature.

This is similar conditions of what a nuclear fallout might bring though with nuclear even greater fears of radioactive isotopes in the atmosphere could last thousands of years. It is highly unlikely that humans survive thousands of years in an underground bunker?
Perhaps the rumor shall come true that cockroaches
which can survive radiation would become the dominant species on earth.

The world has enough nuclear weapons to destroy itself 20 times over.
All it takes is one nutcase regime to use them.
The nuclear age has been a good deterrent
to avoid massive wars between global empires
Though at what price? In 25 years most countries that want nuclear
will have the capability to develop nuclear weapons. Nuclear is one of those
ideas let out of the Pandora's box that has changed the world forever and from no return


The great plagues of Europe taught us a valuable lesson in the power of viruses.
These times were called the dark ages. The population of Europe was cut in half as it took hundreds of years for Europe to recover.
Some theories exist as to why the bubonic plague
took such a painful grip on the people of Europe.

One fairy tail is that a great battle took place
and hundreds of thousands of bodies were left
on the battlefield to rot this allowed for rapid mutation of the bubonic plague and an army of infected rats and lice spread from small towns to the big cities.The great saviors of Europe turns out to be the house-cat
as the cats controlled the rat population and eventually bubonic plague dwindled down.

It is estimated that around 5 % of the euros population was immune to bubonic plague and the descendants of these immune ancestors are also immune to some of the deadly diseases of our time like H.I.V. fascinating how the human body is constantly evolving to preserve itself.

Lack of a food source has pushed civilizations to the brink of collapse.
Something as simple as a single food source which inhabitants come dependent on like the Irish and potato a simple fungus cause millions to die and move out of that country.
Spores and fungus if left unchecked could wipe out whole food sources.
Also We have seen some insects that have falling prey to a fungus
that takes over the insects body similar to how a zombie would act going back to
the hive to infect more insects.

It is widely known that honey bees play an important role in pollinating plants honey bees are becoming extinct in some places without the honey bee humans would be paying astronomical prices for produce. Could you imagine the labor spent on humans pollinating plants? I see in the future a nanobot bee that is programmed to mimic the bees pollination maybe some can be self guided maybe controlled from a video game perspective and the people behind the joystick will do the remote pollinating.
 
Chemical poisoning from making products and the throw away society is real.
The oceans your parents swam in were much cleaner than the ones we swim in today.
We hear it all the time we need more regulation or we need less regulation?
The political willpower is just not going to confront this issue head on.

Were you aware of the great sea of trash that is is churning in the pacific ocean?
In this sea of trash you can see the jellyfish that have consumed the plastic as the jellyfish have transparent bodies you can see the little plastic pieces of plastic shining through the jellys. These jellyfish are favorite foods of bigger fish and turtles
"so as we eat these fish we are eating our own trash."

It is no wonder as the human body is around more chemicals
that our immune system is weakened and we are seeing higher incidents of cancer
and diseases that were once wiped out are coming back stronger than ever before.

Modern medicine is in a race against time.
As cures for disease and technology to protect us
lags behind the harmful status quo that is upon us.
We cannot even begin to tackle these issues
as now jobs are the #1 priority and nobody wants to look like the ones to kill jobs
are we at the point of no return? Will it take horor beyond human perception
for us to recognize the errors of our ways?