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.

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.

human stupidity

Humans.

"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?

Population growth

Humans

It doesn’t help that “Haarp” exists

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?

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.

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.

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

Man killing man kind. Climate change included (but not limited to).

civilization itself

aliens.

Climate change. Hands down.

Organized religion is the biggest challenge, it seems to me. Through scientific study and mutual cooperation, humankind has been able to solve most of its problems. But with organized religion, we get institutionalized superstition replacing science and righteous indignation sewing the seeds of dissension, leading to open hostility and eventually war.

I agree that climate change is the biggest problem. I think it is because it because there is not one single solution. Wind, solar, geothermal, hydroelectric, nuclear, and others all have their place. We are not going to completely eliminate fossil fuels. We need the higher octane for aviation uses. We will find our way through this.

Probably being civil!

I think that the greatest challenge that civilization faces is the inherent failings of the human mind. We tend to tribalism. We tend to hide from reality when it isn't what we want. We trust personal experience more than evidence. In other words, we aren't very good at critical thinking. The greatest challenge to civilization are the same beings who created it to begin with.

The human propensity for jumping from the superstitious religious frying pan into the superstitious ideological fire.

Climate change is a subset of the larger issue, which is the economic system. Call it capitalism with a measure of corporate socialism. By its nature, capitalism must lead to its own destruction. Absent government checks, that destruction is of the ecosystem that supports it.

This isn't to downplay the very real threats of biological agents that will be easy to make with 3-D biotechnology.

And AI, which may be the biggest threat.

All of those statements are correct. I tend to look at root causes historically speaking. Disillusionment is the number one factor. Most people do not understand how civilization is fostered, controlled, and grown through the ages. The use of religion to manipulate the common consciousness has brought humanity to the current epoch in time. The belief in God as foster by the Abrahamic religions. Ibrahim. Judaism, Islam, Christianity. The world stage is set for war.

Modern Humans have grown into a greater conscious awareness. However the Sheeple hold the majority. The wealth of the world is in the hands of the Jewish/Ashkenazi Banking Families, fact. The US is a Christian Nation, we give billions to Israel for absolutly nothing. We are the most indebted nation in the world, and we are about to loose our position as the world reserve currency. Who do we owe money to? The constitutions allows us to print our own money, interest free. The federal reserve is a private corporation. All reserve banks are private corporations.

The paradigm that we face as a civilization, is indeed a Great one!! Global warming is a common occurance, we are going through a pole shift. Many scientist know this amd have communicated as much to the population. We do not know if the shift is quick, or takes decades, most scientist agree with the latter.

They, corporate controlled media, the US is a corporation, never give you whole truths. You are Citizenry, not the People as defined by the Constitution of/for the United States of America. If you understood history and new about the Founding Fathers, you would know this. They despised/hated democracies. They did not want to give you the right to vote, this is why you have an ellectoral college.

Disillusioment is the 1# factoral equation that we face as a problem as a civilisation. This is relative to ignorance of History and Law. What better way to control a society of humans than to introduce gods into the realm of everday consciousness to explain and give meaning to all existentialisms. What better way to be munchkins in the land of OZ.

I would have to say that accepting the fact that we are all human irregardless of the color of our skin, our country of origin, gender, religion (or lack thereof). How we treat each other because of our differences is appalling. We have so much potential but we hold ourselves back because we fail to accept our own differences. Whites and people of color, men and women, Christian and Muslim, rich and poor, we are all against ourselves and for what purpose? Where have we gotten by being against each other? We obviously haven't learned the lessons of the past and continue to make the same mistakes over and over again. We could do so much if we could just accept each other for who we are and quit harping about or differences and instead embrace them. We have a long way to go.