system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't we just start planting trees by the million to combat the negative effects of our carbon emissions?

Edit 1: I'm talking massive scale guys. Funded by the U.S. of fucking A. Im talkin C-130s, DC-10s, that Russian AN-225, fuckin shitting seeds out by the million all over. Africa, North America, Asia you name it. This is the only planet we have we gotta get FIRED UP! Because all I hear is a bunch of bark and not a lot of bite on this issue. So why can't we help Mother Earth do what she's trying to do and plant some fucking trees!

Edit 2: Some great points and information that I did not know, thanks for the input. Seems like mass tree planting is worth a grain of salt in the big picture but wouldn't hurt. Now with the ocean algae seeding, I understand that algae are more efficient than trees at converting co2 into O2, but doesn't that lead to the acidification of our oceans? It seems like the popular trend to cut back and use renewable sources of energy will have the biggest impact, which I think we all agree upon. I'll still try to think outside the box and hope that one of us can come up with a solution global heating.
gpt
It's a very common misconception of how the Earth stores Carbon and how the Carbon cycle works. You see the Earth has huge Carbon reservoirs. The atmosphere and the biosphere (trees/plants) are the two smallest; accounting for a tiny fraction of a fraction of all the Carbon on Earth and only holding onto Carbon for years to decades. This pales in comparison to the Oceans/Sediments/Mantle which hold onto much much MUCH more Carbon for way longer and store it away under ground. THIS is why extracting fossil fuels from sediments and releasing their carbons directly into the atmosphere completely bypasses many reservoirs that make up the Carbon cycle; cycle that can take millions of years to sequester carbon from reservoir to reservoir. 

So next time a company offers to plant trees to offset your plane ticket emissions, realize that they are really just offering to sequester a tiny amount of carbon from the atmosphere for maybe a few decades to offset you burning tons of fuel that was sequestered for millions of years in the ground. Just think about that.