Sea level rise is the only one of those that has _thus far_ occurred. The others are projections for the future. In the case of sea level rise, the author would

Sea level rise is the only one of those that has _thus far_ occurred. The others are projections for the future. In the case of sea level rise, the author would likely claim that human development patterns (e.g. paving everything for parking lots) is a larger contributing factor than the 3.1 cm per decade of sea level rise.