These are extremely slow processes that take centuries to stop. Ever seen large ocean going tankers making turns? They need to start making their turn 15 minutes ahead of time, and once they finally start turning, you can't easily stop them anymore. They respond very slowly.
Our climate is like that: it takes ages to respond. We've been building up excess CO2 in the atmoisphere for over a century now, and we're finally starting to notice the effects. Even if we were to completely stop producing CO2 now, there's still enough CO2 in the atmosphere to continue to increase heat absorption. Even if we could remove all excess CO2 from the atmosphere somehow (we can't), it would still take time for the excess heat to disappear. (The quickest way to lose the excess heat is if we could somehow block the sun, which we can't and would be harmful in a dozen other ways.)
The problem is that this concept is really hard for most people to wrap their heads around, so people tend to simplify it in ways that emphasize the urgency but exaggerate the timeline of the effect, or at least sound like they do, because that's how most people tend to interpret that urgency.
So no, the Earth is not going to end in 4 years, but it will be 4 more years of accumulated damage that will have repercussions for centuries.
Our climate is like that: it takes ages to respond. We've been building up excess CO2 in the atmoisphere for over a century now, and we're finally starting to notice the effects. Even if we were to completely stop producing CO2 now, there's still enough CO2 in the atmosphere to continue to increase heat absorption. Even if we could remove all excess CO2 from the atmosphere somehow (we can't), it would still take time for the excess heat to disappear. (The quickest way to lose the excess heat is if we could somehow block the sun, which we can't and would be harmful in a dozen other ways.)
The problem is that this concept is really hard for most people to wrap their heads around, so people tend to simplify it in ways that emphasize the urgency but exaggerate the timeline of the effect, or at least sound like they do, because that's how most people tend to interpret that urgency.
So no, the Earth is not going to end in 4 years, but it will be 4 more years of accumulated damage that will have repercussions for centuries.