Let's Build A Giant Space Umbrella
When a person is at risk of harm from sun exposure, they just apply sunscreen or wear a hat. So why can't the planet do that? If a six-year-old asked you that question, you'd say "Well ... because ... it ..." then turn on some cartoons to distract them, while you pieced your brain back together. And sometimes those six-year-olds become scientists -- mad they never got an answer to that question -- who've grown up to formulate that exact plan.
It's called a sunshade and operates under the premise that just a 4% reduction in sunlight reaching Earth would be enough to return us to pre-Industrial Revolution temperatures, while not also annihilating plant life or dooming us to an age of rickets and aggressive vampires. The suggested format has varied from a 1,250-mile wide glass shield to clouds of moon dust to 16 trillion butterfly-sized robots Voltron-ed into a 60,000-mile cylinder of transparent film and maintained by "shepherd dog satellites," but they have one thing in common: they all sound like a plot point from a Mass Effect game.
Mikael Haggstrom/Wikimedia CommonsWe're hoping for the glass shield, if only because it's the closest plan to just giving the Earth a pair of rad aviators.
While more feasible than the suggestion to move the planet further from the sun with a massive explosion, any project that would give Arthur C. Clarke's ghost a raging erection still presents a considerable engineering challenge. The BBC helpfully informs us that "By far the greatest challenge is getting the sunshade into outer space," which is like saying that the greatest challenge in becoming Spider-Man is getting spider-powers.
Part of the problem is that the heavier something is, the harder and more expensive it becomes to send into space. So, of course, the proposed solution is to slam a giant electromagnetic gun into the side of a mountain and fire the material into the cosmos to be assembled there, bringing the cost down to mere trillions of dollars. No, the technology doesn't exist yet, but what else do you think America is going to build in the future? A functional social safety net? Don't be absurd. If you're lucky they'll test the mountain gun by blasting food bank donations at Detroit.
There's also the cheap and boring option of merely shooting a bunch of sulfur into the atmosphere, probably with some dumb normal gun, to simulate the aftermath of a gigantic volcanic eruption. In terms of temperature control, this would probably work well as we have enough data on how volcanoes affect the global climate to adjust God's thermostat with considerable nuance. The real concern is that there would somehow be unintended consequences, like a few countries experiencing more climate problems even as the rest of the world benefits. Now, these are all theoretical, "break glass in case of imminent apocalypse" plans, meaning you probably won't see sunshades in the news anytime soon. But you for sure will see our new young adult trilogy about a climate war sparked by the eruption of an artificial mega-volcano.
Let's Dump Millions Of Pounds Of Iron Into The Ocean
The ocean is cool and all, but honestly, what has it ever done for us? Okay, sure, it's a "bountiful source of food" and "helped give rise to life as we know it," but we're not about to just let it coast by on the strength of its old accomplishments. It needs to start pulling its weight in this day and age too.