Just a thesis about global temperature, not an essay.

Since the beginning of the 21st century, the temperature has greatly risen. Although people don't understand how they are effecting the earth, changes are slowly starting to be noticed, such as the melting of the polar ice caps and the rising of sea levels. If people continue living the carefree lifestyles they live, our future generations will be very negatively affected

Greetings!

I think you've got a good thesis started. I have just a few editing tips for you.

Since the beginning of the 21st century, the earth's temperature has greatly risen. Although people do not understand how they are affecting the earth, changes are slowly starting to be noticed - Noticed by whom? Better might be "changes are becoming evident"

Good job!

Thanks,

Sarah, EssayForum.com