The coasts cover a diverse range of ecosystems within marine, estuarine, and freshwater environments. They are some of the most heavily populated and visited areas and are also some of the most threatened natural habitats. Coastal zones are critically important not only to the people who live there but for the health of the planet. Many world estuaries and coast environments are under tremendous stress in response to global warming and the increased anthropogenic forcing. In this talk, I will use several studies to tell a story about how these environments respond to severe human-induced perturbations and climate change. For example, one study shows that general circulation models and dynamic downscaling indicate that the 20 year average recurrence interval (ARI) maximum daily rainfall would increase in the order of 25% in the southeast Australia coast under the high emission future by 2090. Such increases in extreme rainfall are predicted to cause an average increase of 55% in the equivalent ARI flood discharge into the Georges River, which features one of the largest floodplains and urbanized areas in Australia. This study quantifies consequent changes in extreme estuary water levels using the storm surge model RMA-2.