a speech on global warming (100-150) words. urgent

global warming is when the earth heats up(the temperature rises).it happens when green house gases (carbondioxidewater vapour methene)trap heat and light from the sun in the earth atmosphere which increse the temperature.this hurts many people animal and birds.many cannot take the change so they die.many reason may be there for the global warming primary and main cause is considered to be the green house effect.this effect is mainly caused by carbondioxide methenechlorofhloro carbon and nitros oxide etc.