Rachel Carson’s “Silent Spring” in 1962 opens the world’s eyes to the damages humans have caused to the Earth they inhabit. This book exposes the enormous loss of species and environmental degradation as the grave repercussions of pesticide use. Long after her book raised environmental concerns to the public, environmental problems have become increasingly complex and diverse.
Climate change is one of the issues currently in the spotlight. The melting of the polar ice, rising air and seawater temperatures, hydrometeorological disasters, and sea level rise are estimated as the adverse effects of climate change. Although great changes in the climate have happened repeatedly in the past, there are at least two reasons why we need to worry about the ones today. First, the past climate change took decades to occur, while the recent one proceeds at an alarmingly fast rate. Second, the present-day global warming is assumed to be the result of human activities that will almost certainly intensify following rapid population growth and, inevitably, the large amount of energy required to meet human’s needs.
Climate change impact varies globally. Some of the world’s wet regions become wetter, whereas the dry ones are getting drier. The intensity of the changes is also diverse even on the local scale. In Indonesia for example, in Progo Watershed 13 meteorological stations recorded wetter conditions, while the other three stations showed an atypical drier state. Several stations in Magelang Regency, Central Java, Indonesia measured a higher amount of rainfall but fewer rain days. This situation worsens the susceptibility of lahar occurrences in Merapi Volcano in the future particularly when extreme rainfall becomes more frequent.