Climate experts say new evidence suggests Indonesia's seasonal rains will diminish as global temperatures continue to rise. That could mean a devastating blow to the country's tropical agriculture and spark more haze-producing wildfires each year. A new study used samples of coral to track rainfall patterns from more than 6,000 years ago. The study was published a few days ago in the journal Nature.
Study co-author Nerilie Abram says the new data suggest an unexpected link between monsoons and droughts in countries surrounding the Indian Ocean.
"And so the implication is that with monsoon strengthening we expect that parts of Asia and India, where you receive monsoon rainfall, are likely to get wetter. But the knock-on effect is that parts of Indonesia and Australia are likely to get dryer," said Abram. This year's drought in Indonesia is caused partly by a natural cycle of cooling in the Indian Ocean much like the El Nino phenomenon in the Pacific Ocean. But droughts or heavy rainfalls generated by that warming cycle will increase if average global temperatures continue to rise. Many scientists think global warming may be caused in part by increasing emissions of gases from burning fuels such as oil and coal. They recommend cutting those emissions to halt the rise in temperatures.
Abram is a paleoclimatologist who works with the British Antarctic Survey at Cambridge, in the United Kingdom. In a phone call from Cambridge, she said recently that the coral study shows droughts also are shifting to a different time of year.
"And that the peak of drought could actually shift so that it falls at the time of year when this area receives its most rainfall," added Abram. "So that sort of change could have quite a critical effect on agriculture in the area, and actually change the way that we need to try and adapt to these events." Millions of impoverished Indonesians in rural areas depend on subsistence agriculture, which could be harmed by drier weather.
In the past several months, the severe drought was blamed for massive forest fires in Indonesia, which caused thick smog and health problems in neighboring countries.
