ABSTRACT
Human activities have increased the concentration of carbon dioxide (CO2) and many other greenhouse gases (GHGs) in the atmosphere. With the increases in GHGs, the average temperature of the Earth and oceans is on the rise. Projections from climate models show that the global sea level will continue to rise in the 21st century. Though the sea-level rise (SLR) is a slow process, there is an increased risk from waves and storm surges formed over the elevated sea damaging coastal regions. It will also result in the penetration of saline water into the coastal freshwater resources. The coastal cities, fisheries, landscapes, military bases, beaches, and boardwalks face a growing risk from SLR. The impact of climate change on snow, ice sheets, and glaciers is resulting in ice melt and increasing water in the sea. The volume of water in the ocean is expanding on its warming up. These two processes are causing SLR at present at a rate of 3.3 mm per year. The IPCC assessment reports, observed data, and the projections from climate models indicate that in the past few decades, the SLR has accelerated. There are estimates under the different GHG emission scenarios describing the likely severity of the SLR. The threat is not only of some low land and wetlands getting submerged in a few centuries but also a number of impacts on the weather patterns, climate subsystems, agriculture, forests, environment, and ecology. Measures to control the GHG emissions and subsequently reduce the rates of SLR are also described. This chapter aims at deliberating on causes, measuring, risks, and impacts of sea-level rise. It also includes impacts of climate change, projections through climate modeling, and also preparedness through reducing the GHG emissions and responding to SLR impacts.
