i want to write an essay about environmental issues.please help me

Follow the writing process, whether you're writing for science, history, English, or whatever:

Prewriting: brainstorm, research, plan, outline, thesis statement

Writing: write first draft by starting with section II of your outline; write introduction after the body of the paper is written; write the conclusion last.

Polishing: revise, concentrating first on the body of the paper, then the intro, then the concl (revision = making sure ideas are logical and sequential and support your thesis); proofread (spelling, grammar, usage, etc.)

Do you have a thesis yet? Have you done your brainstorming (and maybe research) yet? Have you written an outline?

http://leo.stcloudstate.edu/catalogue.html#org
from http://leo.stcloudstate.edu/catalogue.html

http://owl.english.purdue.edu/owl/section/1/1/

http://www.angelfire.com/wi/writingprocess/

http://grammar.ccc.commnet.edu/grammar/
Check in the Essay & Research Paper Level.

Only you can decide which environmental issue you wish to write about. Make sure you don't let your topic be too broad, though. And make sure it's a topic about which you have a very clear opinion so you'll be able to write a good thesis statement.

Let us know.