system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't we convert greenhouse gases into another gas that doesn't trap heat?
gpt
CO2 is a very low-energy molecule. In order to break it apart, you need to add energy to it.

Plants do this using sunlight as an energy source for photosynthesis, turning CO2 and water into sugar. Whenever we eat the products of those plants, we eventually reverse that process, turning the sugar into CO2, water, and energy.

The real problem with our greenhouse gases is that normally that cycle of plants taking in CO2, plants being eaten, and then animals exhaling CO2 is a closed cycle. The amount of Carbon between the atmosphere, plants, and mammals remains pretty constant. However, millions of years ago, there were some trees that didn't get eaten by bacteria when they died (there just wasn't a bacteria that could eat them yet back then).

This resulted in a lot of dead trees capturing carbon outside of the natural cycle. Those trees eventually got buried underground as the Earth shifted around, and over millions of years have broken down, and are now what we call fossil fuels.

Whenever we burn fossil fuels, we reintroduce that carbon into the cycle. Without more plants or animals for the carbon to live in, all that extra carbon in the cycle ends up in the atmosphere.