Islam.
Humanity has a fair chance of dealing with global warming, but Islamic world conquest will result in the end of civilization.

The big question seems to be why aren't we... humanity/nations doing more... doing anything really significant about climate change? Maybe in dark back rooms in private meetings, the power-that-be don't want to actually do anything... not yet. Not until a large portion of the population is gone.

aliens.

In 5 billion years the sun will go red giant and swallow the earth - need to figure out a way to survive off this planet or we're doomed.

The reason the Reepublicans do not like to talk about climate change is because they are making a lot of money selling gas as in gasoline and natural gas. As long as profit talks they will no acknowledge climate change.

Civilization.

All problems humanity is facing and will continue to face going forward is the world population....... That's the root cause of all present and future problems

Climate change is not the greatest challenge of civilization. Climate change is a byproduct of a society that prioritizes poorly what we should be concerned with. This is due to a combination of dishonest leaders and massive mistrust in anyone outside your preconceived ideas.

If our society could properly focus on what is important, climate change and the problems it would cause for humanity has simple answers that we can put into place if we could figure out how to agree on facts and work together.

Politicians generally only look to the next election. Trump knows the coal mining and other industries which use fossil fuels are behind him, and the workers who are employed in these industries will re-elect him if he keeps his promise to trash all the green energy initiatives. I just hope all the other countries who have signed up to the Paris Climate Treaty keep to it, but we need the US on board too.

"Plot idea: 97% of the world's scientists contrive an environmental crisis, but are exposed by a plucky band of billionaires & oil companies."
I quoted a tweet from someone else here because it captures in a nutshell how absurd it is to still be denying climate change and that mankind is predominantly responsible. This has been known now for 30 years and the evidence still being collected unambiguously supports this.
This is so much like when Big Tobacco created disinformation campaigns to confuse and cast doubt on cigarettes causing cancer. Now we have Big Oil with Trillions of dollars at stake trying to do the same thing and they know how to influence the government, they have politicians bought and paid for and they have a propaganda campaign where is no object.
This is so obvious, the science is clear, the evidence is clear, but it's easy to confuse the public.
United States is the only developed country, for example, where more than 60% of the population does not believe in Evolution. There is so much religious and political propaganda.
Yes, climate change is an existential threat even the Pentagon realizes this.
What do we have to lose by developing alternative, renewable and clean energy. Nothing to lose, everything to gain... so why are they trying stop it?

As humans in many cultures in many time periods we have destroyed our environment, causing the need to abandon cities (like Anchor Watt, many Mayan and Aztec cities and other ancient cities all around the world).

We evolved to survive immediate dangters and to supply immediate needs, but it doesn't appear to be hard wired into us to take care of our environment, and now we are destroying our entire planet, not just a few random local environments. We have few and swindling place to move to left on this planet.

not being able to find common ground something will always come up that mkes us right and them wrong no matter who we are it always happens

plastic!

Survival

Humans.

Advancement

Problem is with short-term thinking. Getting a tax break at the expense of clean air and water for our children and grandchildren is a pretty bad investment. Makes sense if you only care about yourself, i.e. you’re a Republican.

human stupidity

Ignorance

at jorj. your words I quote from below. "at least the republicans aren't making false promises to get votes. And the dems are more evil?" -Excuse me, I can't be kind about this. Are you XXXXcking stupid?? What rock did crawl out from under?

It doesn’t help that “Haarp” exists

How about peace? That might solve a multitude of problems

Humans

Long term, you are correct. In the short term, our greatest threat is the culture of greed, corruption, and ethnocentrism exemplified by Trump and his supporters.

Our greatest challenge is pulling soo many heads, out of soo many assess. I think once we figure that out, the rest will fall into place