Greetings!
If you are doing a "research essay" then you will need scholarly sources from peer-reviewed journals and books on the subject. When you are using the computer at school, you can log into your school library's online databases and find the information you need, using such databases as Academic Search Premiere, JSTOR, and others. It is the same information that appears in the print versions of those sources, so it's unlikely that your teacher meant you not to use them. You can find what you need, print the information and take it home with you.
We cannot do your research for you, but I can give you some ideas for the issues to look at. You might want to explore such topics as the history of climate change, the change in scientific opinion about global warming over the past three decades, what governments are doing to address the issue, how strong the evidence is for a need for immediate action, and what can be done to address the problem both now and in the future.
Best of luck in your studies!
Thanks,
Sarah, EssayForum.com
Sarah, EssayForum.com