Climate change has been revealed to increase the occurrence of natural disasters and to damage ecological systems. In coastal regions, there are many environmentally significant areas from the viewpoint of biodiversity, such as areas registered under the Ramsar Convention. The Kushiro Wetland is the largest wetland and one of the most significant natural systems in Japan, remaining mostly unaffected by human activity. In the wetland, there are many species, which do not tolerate saltwater. When the sea level rises, the communities of freshwater plants and fish may die out due to the extension of salt wedge intrusion along the Kushiro River. Therefore, in this study we make an attempt to understand the impact of sea level rise on the ecological system of the wetland by using a three-dimensional numerical model, which allows us to evaluate the effect of sea level rise on salt wedge intrusion. It is revealed that the National Park area may be affected by salt water when sea level rise reaches about 0.15 m. Also, the maximum sea level rise may induce saltwater intrusion into the Ramsar area. As a result, we proposed an adaptive management strategy for protecting the ecological system of the wetland from salt wedge intrusion.
We report a time series (1948–2100) of global-scale meltwater from mountain glaciers and ice caps (MGI) estimated by the global glacier model HYOGA2. HYOGA2 calculates the temporal fluctuation of the mass balance for 24,234 individual glaciers worldwide. It covers 90% of the total glacier area, except for glaciers in Greenland and Antarctica. HYOGA2 also accounts for regionally distributed changes in glacier area and altitude associated with glacier retreat and advance. By computation of individual glacier changes, future dissipation and glacier mass and area changes can be simulated in the model. The cumulative volume loss of water between 1948 and 2005 was estimated to be 25.9 ± 1.4 mm sea level equivalent (SLE). A future projection under a high-emission scenario demonstrated significant losses of water from MGI equivalent to 60.3 ± 7.9 mm SLE between 1948 and 2060 and 99.0 ± 14.9 mm SLE between 1948 and 2099.