I'm talking about the report that this story is about. I picked up the discrepancy right away - maybe I've got some warped sense of logic and economics but it stood out right away. Even more so, the headline is pure bullshit, too.
What am I talking about? Well, money is like energy, matter, and the ecology. There's a certain amount to go around, no matter how you try and stretch and squeeze it, there's a certain amount of value and that's it. So the report that's at the heart of the story is kind of wrong. Some of the value of reefs is in tourist dollars, that will be gone from the reef tourism scene but it doesn't mean the money will vanish in a puff of smoke - it will just be spent elsewhere.
And some of the value of the reefs is in fish that will have to be replaced by food from another source. But again, either you go out and catch fish at whatever that costs in materials and energy and so forth, or you pay money for someone else to spend that kind of materials energy and etc, in some other place.
Protecting coastlines? Yes, that will mean that coastlines will erode in places, but in other places there will be deposition of material, too. It's a loss to humankind and many animals and fish that depend on it, but to the Earth it's just a change.
And as for the headline, that is just a reporter who didn't work things out before reaching for the keyboard - $172bn will not be "sucked out of the economy" - it will only move from reefs and businesses surrounding the reefs to other areas and businesses.
Think of wealth (==money) as water. Now think of the Earth as a big closed bucket full of water. Now take "$172bn" worth of water from one edge of the bucket to another spot. Did the water magically get "sucked out of the economy?" Of course not. There's so much water before, and the same amount afterwards.
Boo Treehugger for making such an erroneous headline, too.