Some people are worried about an asteroid hitting the Earth, and about our inability to stop one if it's bearing down on us. I agree that someday (undetermined), a large chunk of something is just about certain to intersect this planet's orbit. It's been hit before, more than once; it'll be hit again. A collision with a large enough chunk may cause a mass extinction. So "someday" this will happen and it's possible that--with enough advance thought and preparation--and if it happens while there are still wealthy human civilizations on the planet--it might be possible to avert the collision by either moving the chunk away or blasting it into particles too small to survive re-entry.
Other people are worried about climate change resulting from an increase in the carbon dioxide in the Earth's atmosphere. This isn't something that will happen "someday"--this is happening now. This isn't something that might affect your life and mine--it's affecting it now. It's affecting every human on the planet , and it's going to affect all of us more in the next year, five years, ten years, whether we take the necessary actions to ameliorate it (it's no longer possible to stop it before it starts getting hotter...that's already happened) or not. It's just a question of how bad it's going to be for how many people. It is certain that if the planet warms up enough, there will be mass extinctions (there are already extinctions.) Moreover, this isn't something where we "might" be able to do something about it....we can do something about it (not prevent or reverse it right away, but something) and what to do--the broad outline--is known.
So why would anyone fixate on an uncertain potential disaster and a very uncertain potential fix, when we have a planet-sized debacle going on now?
It's the old scutwork v. exciting stuff problem.
Back when I was a kid, and we were all expecting WWIII with nuclear extinctions, a lot of us kids argued with our parents that the ordinary chores didn't count anymore. Why wash the dishes, if they could be blown up any minute? Washing dishes is boring, routine, unglamorous. Why not spend the time doing something exciting and heroic? If the world's going to end, who wants to be known as the world's most diligent housekeeper?
What's considered exciting and heroic? Risking one's life and killing other people, primarily. Or the less bloody equivalents of getting rich and backstabbing competitors. Being a rock star, a movie star (a celebrity, in any form), "your fifteen minutes of fame..."
What's considered mundane, boring, routine? Everything that sustains a civilization, from carrying out the garbage to growing the food to washing the dishes.
Even though an army marches on its stomach (something the ancients knew), and even though the means of killing always involve the contributions of many who are doing something routine (manufacturing, transporting) and a lot of routine maintenance...even though the mountain climber's clothes, boots, ropes, carabiners, pitons and other gear were made by someone doing a routine job...even though behind every celebrity is an army of people doing their scutwork...those with their noses on the grindstone, their hands in the dishwater, their fingers sewing the seams, their eyes on the road as they transport the goods are perceived as the boring nonentities, and their jobs as less worth doing and less fulfilling.
Did I hear a "Yes, but..." in the background there? Yes, but we all want the limelight. Yes, but we'd all rather have a glamorous job, our faces in the magazines, our voices heard by millions, billions...
And if we all did that the world would've fallen apart long ago. Somebody's got to fix the roofs, mend the pipes, patch the roads, inspect the bridges, put gas in the tank and change the oil, clean the babies' bottoms, grow the food, transport the goods, cook the meals, mop the floors, wash the clothes...and the dishes.
When I argued with my mother that washing dishes was kind of silly if the Reds were going to bomb us out of existence in the next week, she said "Wash them anyway." She said much the same thing every time I brought up a potential disaster that I thought should get me out of doing something boring I didn't want to do (homework, housework, whatever.) She knew that fixating on some possible distant doom was an excellent way to not see, and avoid, what needed doing here and now. And she was right. If I had not washed the dishes from then until now because WWIII was about to break out....there'd be a stack of dishes from here to outer space. Dishes were dirty; they needed washing.
The planet is dirty...we dirtied it. Like me as a child, leaving milk-scum glasses around the house (something else my mother complained about) we humans have left our smudgy dirty mark on the sky...our trash on the land...and it's time we cleaned it up. Because if we don't, it won't matter whether an asteroid hits the planet in a few years....or a lot of years. You and I and our children and grandchildren and great-grandchildren won't have the resources--human or material--to do anything about it, even if they're still alive.
Rock falls out of the sky...someday for sure, maybe soon.
Sea-level rise, extinctions, disease, hunger, from a hotter Earth....now for sure, right now, not someday.