The bushfires that swept through Australia last year were connected to a phenomenon known as the Indian Ocean dipole (IOD), which is expected to become more frequent due to climate change, a geologist studying coral fossils said yesterday.
National Taiwan University Department of Geosciences professor Shen Chuan-chou (沈川洲) since 2001 has been working with Australian and US researchers to study climate systems in the Indian Ocean.
Led by Australian National University Research School of Earth Sciences professor Nerilie Abram, the team published a paper on IOD in the journal Nature on March 9.
Photo courtesy of Nerilie Abram via CNA
The bushfires resulted from a positive IOD event, when the region east of the Indian Ocean becomes drier and there is a reduced chance of rainfall in Australia, Shen told an online news conference held at the Ministry of Science and Technology in Taipei.
To understand the change in climate over the past centuries, the team drilled the cores of live and fossil coral off Sumatra, Indonesia, as coral can be viewed as a thermometer of ocean temperature, Shen said.
Shen’s laboratory used radiometric uranium-thorium dating techniques to identify the ages of the coral samples.
The most important finding was that the climate systems in the Indian and Pacific oceans are “interconnected,” which previously had been a disputed hypothesis, he said.
While similar dating techniques used by other laboratories might have a margin of error of one to two years, Shen said that his laboratory had reduced the margin of error to as little as three months.
The team found that positive IOD events often occur in conjunction with El Nino in the central Pacific Ocean, he said.
Models show that strong IOD events have been increasing and they might become more extreme due to global warming, he added.
Nonetheless, an IOD event in 1675 was estimated to be 42 percent stronger than one documented in 1997, showing that such events are also possible without human-caused global warming, Shen said.
Referring to previous studies of El Nino, Shen said that climate oscillations in the Indian Ocean also affect the climate of Taiwan.
If the temperature in the central Pacific is rising, more typhoons form in the summer and more strike Taiwan in the fall, while rainfall in spring decreases, causing droughts in southern Taiwan, he said.
The government should formulate more policies to mitigate the effects of climate change, Shen said.
TRAVEL FACTOR: The party’s chairman said that the key to a successful recall of the Kaohsiung mayor was turnout among young voters from outside the city More than 55 percent of Kaohsiung residents said that Kaohsiung Mayor Han Kuo-yu (韓國瑜) should be recalled, the New Power Party (NPP) said yesterday, citing a poll. The COVID-19 situation and turnout among young people would be two key factors determining whether Han is removed from office, the NPP said. The telephone survey showed that 59.5 percent of respondents said they would vote in the recall election, down 6.1 percentage points from the results of a similar poll last month. Those who said that Han should be recalled rose 4.3 percentage points to 56.4 percent, while 28.9 percent said they disagreed with the
Wecare Kaohsiung founder Aaron Yin (尹立) yesterday filed a complaint against the Kaohsiung City Government for launching a NT$50 million (US$1.67 million) stimulus program to boost consumer spending, which Yin said has contravened the law, as it uses public money to counter a recall vote against Kaohsiung Mayor Han Kuo-yu (韓國瑜). Yin and his lawyer went to the Kaohsiung District Prosecutors’ Office to file a complaint and ask that an investigation be launched. They accused the city government of wrongdoing, illegal activities, undue profiteering and contravening the Civil Servants Election and Recall Act (公職人員選舉罷免法). Han on Tuesday unveiled the program, which is to
’DESPERATION’: Reminiscent of Russia’s annexation of Crimea, Beijing is taking a calculated risk by acting first and resolving recriminations later, Wu Rwei-ren said China is sounding the battle horn for a new US-China cold war by proposing a national security law for Hong Kong while the West is preoccupied with the COVID-19 pandemic, an academic said yesterday. Academia Sinica Institute of Taiwan History associate research fellow Wu Ruei-ren (吳叡人) made the comments at a news conference in Taipei, saying that he was representing the Economic Democracy Union’s research branch. The resolution signals China’s abandonment of the “one country, two systems” framework, as it prepares to take full control of Hong Kong, ending the era of Hong Kong as an international financial center, which was made
Suspension of the Act Governing Relations with Hong Kong and Macau (香港澳門關係條例) would be the equivalent of cutting off Hong Kong, Chinese Nationalist Party (KMT) Chairman Johnny Chiang (江啟臣) said yesterday. “Without [the act], how will you stand with the people of Hong Kong?” Chiang asked outside the Legislative Yuan in Taipei. President Tsai Ing-wen (蔡英文) on Sunday wrote on Facebook that Taiwan, like all democratic nations, stands with the people of Hong Kong as she expressed concern over China’s plan to impose a national security law for Hong Kong. For security reasons, Tsai said her administration would consider invoking Article 60 of