CITYWIDE — While the housing market here may be experiencing a slight cooling trend, fears that an imminent implosion of the housing bubble are unwarranted, at least when it comes to the city by the sea, local real estate experts said. “We are seeing in Santa Monica, as with everywhere, that the housing market is slowing down, but that’s in comparison to two years of unstable appreciation rates,” said Delores Conway, Ph.D., director of the USC Lusk Center for Real Estate and co-author of the Casden Real Estate Economics Forecast. “Trees don’t grow to the sky and we can’t have 20 percent or double digit price increases year after year,” Conway added. “That’s just not sustainable. I think we’re coming back down to Earth.”