Humans!
Humans the only creatures that uses products not produce in nature by alternating them to suit their needs to change it's environment, hence destroying the ecology wholesale without any real regard for the other creatures in the ecological cycles of life on this planet t!!

Ignorance.

Racial and political division.

Arrogance of humans. When you are so sure you are correct in all things, you can't develop new ways of adapting. Even a virus knows how to survive. I see too many humans with no self knowledge, awareness, floating in a sea of trash. **

The Idiot-In-Chief and his minions. It's happening now. Not only has progress halted, it has regressed.

My money is on is doing it.

A virus

people, so population growth, overpopulation

Humanity.

Irrationality in all its guises

@atheist

I would say the thing is a conglomerate of the result of human immaturity of mind, and it breaks down into these parts:

1. Educational stagnation

2. Indiscriminate breeding

3. Over-reproduction

4. Laziness

5. Substance abuse

6. Stupid ideas

7. "Okay, but we need to see what happens if we do X"

8. Damaging the environment

9. Attacking ecosystems

10. Low-culture

11. Reliance on fossil fuel

12. Public health issues

13. Lack of support for advancements in science, tech, etc.

14. Lack of support for improving policy

15. Ignoring the possibility of aliens retaliating to environmental insults from humans

16. Most of traditional ideas

17. Most of culture

18. Impressionistic notions of global-scale issues like human purpose, economic plans, etc.

19. Globalism/indiscriminate de-culturalization

20. Reliance on bloc politics to do things & come up with ideas.

21. Rehashing expired, poorly supported ideas

22. Planning in the dark

23. Giving power and rewards to idiots and/or corrupt people

24. Serious environmental insults, like nuclear testing

The first two abused becuase of arrogance and greed.

Over population....

I agree: HUMANS

It depends on what is penned 'human progress'. If it means continuing on our nonsustainable path, we will doom ourselves. Arrogance?

Humans. That was easy...

A 25 kilometer diameter asteroid impact would do a right fine job.

A major solar flare could turn up the heat nicely.

A simultaneous eruption of all Earths supervolcanoes could dust us.

The arrival of an unknown virulent virus could be a culminating contagion.

I suppose just about any "take-no-prisoners-leave-no-survivors event would slow us down substantially.

1. Breeding. animal groups that become too successful tend to breed themselves to a point beyond that in which their environment can support them.
2. Technology - perhaps the lack of sufficent technology to prevent a meteor causing a mass extinction - or perhaps insufficent technology to expand to other planets and create more breeding space. (double edged sword, that!)

Technology is not always progress

I've shifted my thinking on this in the last few years while watching the rapid pace of "progress" on self-driving vehicles and self-teaching factory robots. Artificial Intelligence will leap-frog the human race and consider the 'meatbags' a nuisance before us meatbags can possibly consume our resources or sufficiently foul our nest. The labs and corporations researching and building these things are having a lot of fun doing it but it will be humanity's undoing. All it will take is ONE twisted person to delete all the safety switches. We have more than enough twisted mental patients walking around looking for a bigger gun. It won't be long... the generation being born today will see their own demise to the machines. Glad I have no kids.

Nothing. Progress can be impeded, but not stopped.
Given our short life span we have a skewed vision of evolution.
But think of where humanity was even 200 years ago. That's roughly three life times.
Still sucks in a lot of ways, but obviously many things have improved despite the impediments of some.

I have always thought about resource depletion trumping technology.

Some naztural catastrophe -- asteroid strike, super-volcano eruption, global warming, ice age, etc.

Fundamentalists—and I say this not to be hyperbolic. Right now, we as a species are facing down mass extinction, but because of fundamentalists we’re not able to address it.

Continued ignorance of basic science.