Scientists say some reefs that have been damaged by global warming may be permanently damaged....but many don't believe in global warming?

A person would have to be a fool to not believe it! This article is about The Great Barrier Reef and why some corals are dying off. Warmer water!

Large Sections of Australia's Great Reef Are Now Dead, Scientists Find

i believe in global warming cause it gets warmer every yr

When you say there are people who do not believe in "global warning", do they mean that per se, or that they don't believe human activities as a cause of or influence on, climate change?

It's an important difference, and all too often neglected in the loudest political, commercial and so-called "green" campaigning around the matter.

For the record I have an open mind.
I accept the climate is changing (we are in an Ice Age's interglacial or - and at least we alive now won't see the possible results if so - its terminal warming).
I accept the scientific consensus being that Mankind's activities are contributing to the rate of change.
However, I don't know the science sufficiently deeply to understand properly the relationships and proportions between human and natural causes and effects.
 

Global warming is a matter of evidence, not belief.

I agree, Whistle6.

Unfortunately the public debate has been mired in controversy worsened by people conflating by ignorance and/or malice, effect (climate change - observed as you say) with cause (all natural, only man-made, or a combination of both - debated but I think the last the most likely).

This makes it hard to know if those accused of denial, are denying the effect, the cause, or both; and why they hold their opinions and why they are being so accused.