Humans have fuc#?! up the world!

Originally, as an Exen-human, your only task was to spy on humans and occasionally send a status report to your home planet. So, it was a really laid-back job. But then humans started destroying their own planet by driving CO2 levels to unprecedented heights and completely heating up the Earth. Now, the population is already in a state of emergency. In order to keep your job, you must now save the planet. To do this, you cultivate plants from your home planet to lower the CO2 levels and reacclimatize the Earth. You still have some seeds lying around for this, but you'll need to collect the rest from planted trees. However, you can only plant the trees in your Exen form. And apparently, humans don't like Exen-humans who want to plant alien plants in their neighborhood. Since your employment contract states that you must not harm any humans, your only option is to run away and plant your trees as quickly as possible.