Dragons of dual element

Dragons have been hatched recently with dual elements e.g. Fire & Water, Air & Earth, fire & Earth etc, now Dragons normally only have one element, they know about all elements but only have one in themselves. Dual Dragons have been appearing in the last 10 years, why I have not yet been told, they are similar to our Blue Star and Crystal Children that are being born.

I have a theory that these Dragons will be working very closely with Humans in the fight against Global Warming and Climate Change, but as I say this is only my theory and I have yet to do any extensive meditation on it to have this confirmed or denied.