Fire concerns for green roofs

So, apparently green roofs will burn.  (Here's a video of a green roof on fire, from the wonderful Green Building Law Update.)

This makes a lot of sense - I know someone who let a trash burning take over a meadow, so why would an artificial meadow be different?

What concerns me more is:

1) How resistant to heat/damage are the underlying parts of the assembly, which seem to feature plastics?

2) What does one do to the owner's insurance rates when one chooses a green roof?

3) How do the firefighters feel about their ability to do their job when a green-roofed building is on fire...I've heard that some firefighters don't like metal roofs, as they're harder to get through to access a burning attic.  Even though the insurance rates are lower, for metal roofs.

I'm sure more data will come to light on this notion soon.

Comments

[Jorg Breuning]

There are no concerns with green roofs when done right!
Germany has over 1 billion square feet of new green roof construction every year - since more than 20 years. There is no fire reported!
As said - when done right - regarding materials, plant selection and use of green roof.
I wouldn't say tray systems - as seen in the movie - are the best solution against fire hazards but it is a good start.
I understand that America is concerned because America is behind most environmental technologies or often tries to reinvent the wheel.
jbi

[Rodney Orton]

Wait, green roofs had been in used in Norway for centuries and I'd never heard of an incident involving fire because of these roofs. Green roofs are also a growing trend in Japan because of the lack of space for gardens. I think yeah, if properly done, green roofs are definitely safe.

[Galliena Gornet]

Would an access door to the attic solve the problem with metal roofs? What can you suggest to the homeowners who already have metal roofs for their houses?