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new map shows that Java, Bali and Nusa Tenggara are now more vulnerable to severe impacts from climate change.

According to the map, titled “The Atlas of Climate Change Vulnerabilities in Java, Bali and Nusa Tenggara”, which is published by the Meteorology, Climatology and Geophysics Agency (BMKG), some areas in the regions are now more prone to natural disasters, compared to 30 years ago, such as torrential downpours and extreme dry spells, which are partially linked to climate change.

The map explores trends of three key climate parameters, consisting of “dry spells” or periods of time when there is no rain; “wet spells” or uninterrupted rain over a particular period of time; and the frequency of 50-mm-plus rain per day.

Dedi Sucahyono, a climate researcher at the BMKG’s center for climate change and air quality, said the agency now relied on changes in rainfall patterns as a basis for the map.

Studies on the three parameters show that significant, characteristic changes in climate have taken place in Java, Bali and Nusa Tenggara between 1970 to 2010.

Some areas on Bali, such as Bangli, Gianyar and Karang Asem, for example, are now more prone to long dry spells compared with three decades ago. Meanwhile, other areas, such as Buleleng and Tabanan, are tending to be wetter during the dry season.

The map also indicates how during the course of the last 30 years, Cirebon in Central Java has become more vulnerable to heavy rains of more than 50 mm per day.

Other areas increasingly prone to heavy rainfall include the central part of West Java, including Bandung and Purwakarta; Yogyakarta and its surrounding areas, Boyolali and Magelang; Batu in Malang, East Java; and northern coastal areas of Java.

“Seasonal changes will impact many sectors, especially agriculture, as for most farmers it’s no longer easy to decide when is the best time to start planting primary crops,” Dedi told The Jakarta Post on Monday.

The BMKG’s deputy director for climate change information, Nasrullah, said for a complete picture of areas most vulnerable to climate change, the map needs to also consider carbon dioxide (CO2)
concentration.

“We need to look not only at the air quality or the changes in rainfall patterns, but also at an entire range of components, including whether there is a correlation between changes in rainfall with concentrations of CO2 in the atmosphere,” he said.

For instance, data provided by the BMKG’s Global Atmospheric Watch (GAW) observatory station in Koto Tabang, West Sumatra, shows that an increased level of CO2 in the area is playing a key role in spiking local temperatures.