Upon over 40 years of endeavour by the GEO, the overall landslide risk in Hong Kong has been less than one-fourth of the risk level in 1977, whereas casualties due to landslides have also dropped significantly in recent years. However, landslide risk is increasing with time due to the continual population growth of Hong Kong, which has resulted in encroachment of more urban development onto steep hillside. The potential landslide risk brought about by slope degradation and extreme weather, which can be exacerbated by climate change, must not be overlooked.

In recent years, extreme weather exacerbated by climate change has brought about many disasters worldwide, causing significant casualties and economic losses. As for Hong Kong, in June 2008, a record-breaking rainstorm struck Lantau, resulting in over 2,400 natural terrain landslides, 2 fatalities and havoc in western Lantau. According to the assessment of GEO, if the June 2008 severe rainstorm were to strike the densely urbanised area of Hong Kong, a large number of severe landslides including debris flows on natural hillside would occur. The landslides could block roads, damage buildings and affect other important facilities, and the occurrence of severe landslides resulting in significant casualties and economic losses could not be ruled out. Worse still, if an extreme rainfall event like those that affected other parts of the world in recent years (e.g. Typhoon Morakot that hit Taiwan in 2009) hits Hong Kong, much larger scale and severe landslides could occur. This demonstrates the importance of getting prepared for extreme landslide events through taking suitable measures in response to a changing environment.