system
Given the following post, respond as if you're commenting on Reddit:
human
What's stopping us from sending lichens, algae, and other extremophile bacteria to Mars and start trying to change the atmosphere now?

Fully terraforming will take a long time so why not start early and send stuff up with the next rover.
gpt
There's nothing stopping it from happening theoretically, but for now, NASA is trying very hard to prevent contaminating Mars with life from earth. 

Any kind of organisms that could be found on Mars should be studied, and if you just ship a bunch of extremophile bacteria from earth to Mars, you contaminate the planet with potentially invasive species. 

There might come a time where humanity will attempt to colonize a planet, but for now it's both unproductive and virtually impossible.