In August 2009, Typhoon Morakot brought record-breaking levels of torrential rain to central and southern Taiwan. During the four days that the storm hung over the island, some areas experienced rainfall totaling around 3,000 millimeters—an amount surpassing normal annual precipitation for most places in the country. To date, Morakot is the wettest typhoon ever recorded and the most devastating storm to strike Taiwan.
Typhoons are a fact of life for countries in the northwestern Pacific Ocean. Taiwan, for instance, averages between three and four typhoons per year. However, there is growing concern in the scientific community that the nature of these storms is changing. During the same month that Morakot struck Taiwan, the American Geophysical Union, a nonprofit organization that seeks to promote discovery in earth and space science, agreed to publish a paper by Taiwanese and mainland Chinese researchers in a September issue of its biweekly scientific journal Geophysical Research Letters. The paper, titled “Temperature Dependence of Global Precipitation Extremes,” identified an alarming increase in heavy rains from tropical storms while also proposing a culprit for this phenomenon: global warming.
Based on a statistical analysis of records covering the period 1979 to 2007 from the Global Precipitation Climatology Project data set, the researchers determined that the amount of precipitation from the top 10 percent of the heaviest rains over the course of a year had increased by about 50 percent worldwide. Conversely, the amount of precipitation from the bottom 50 percent of light-to-moderate rains had decreased by 10 percent. Furthermore, by analyzing data from the Taipei-based Central Weather Bureau for the period 1961 to 2005, the researchers found that the amount of precipitation in Taiwan from the top 10 percent of the heaviest rains from typhoons had risen by approximately 100 percent, while light-to-moderate precipitation from the storms had fallen by about 20 percent.
Liu Shaw-chen (劉紹臣) is a scientist at the Research Center for Environmental Changes (RCEC) at Academia Sinica, Taiwan’s foremost research institution, and the lead author of the paper. According to Liu, there is little doubt that global warming is the major contributing factor behind the surge in heavy precipitation from typhoons, which is making flooding more frequent and severe while simultaneously increasing the likelihood of droughts due to the decline in light-to-moderate precipitation. That is to say, Morakot would not have brought such heavy rainfall to Taiwan without global warming. “Changes in precipitation extremes have a serious impact on the welfare of human beings and the entire ecosystem,” says Liu, who was awarded the rank of academician, a lifetime honorary title, at Academia Sinica in 2012. “Hopefully, the government considers our research when formulating national strategies for flood control, land use and water resources management. Maybe the study can also help raise the public’s awareness of the effects of climate change.”
Environmental changes are accelerating worldwide, posing complex challenges for humanity. In Taiwan, several academic and research institutions are striving to map the extent of these changes and assess their causes, impacts and risks. Established in 2004, the RCEC is one of the nation’s leading climate change research institutions. It grew out of a project initiated by Academia Sinica’s Institute of Earth Sciences in late 1999 to address the problems of air and water pollution and climate change in Taiwan.
The research projects implemented by the RCEC are focused on air quality; atmospheric chemistry; biogeochemical cycles of freshwater systems in Taiwan and the surrounding oceans; regional climate change; and water resources. The programs have already produced some significant results. In addition to the findings on the correlation between global warming and increases in heavy precipitation, Liu’s team discovered that the main cause of an approximately 15 percent reduction in sunshine duration in Taiwan from the 1960s to the 1990s was a rise in aerosols and/or cloud albedo—a measure of how much sunlight a cloud reflects—as a result of growing anthropogenic, or human-caused, emissions of air pollutants.
The environment in Taiwan, Liu says, has deteriorated severely over the last five decades due to surges in energy use and serious air pollution. “An increase in aerosols and cloud albedo leads to decreases in sunshine duration, diurnal temperature range and near surface relative humidity, coupled with a rise in the intensity of extreme precipitation events,” he notes. “All these phenomena have profound implications for the climate and ecosystem of the region.”
Research on problems of this magnitude is often best achieved through collaborative endeavors. In 2011, the National Science Council (NSC), which became the Ministry of Science and Technology in February this year, launched a five-year project called the Consortium for Climate Change Study (CCliCS) that brings together researchers from the RCEC and professors from some of Taiwan’s foremost higher education institutions, including National Taiwan University (NTU) and National Taiwan Normal University (NTNU), both of which are in Taipei City.
Modeling and Simulations
The core component of CCliCS is the Laboratory for Climate Change Research (LCCR), which is housed at the RCEC. Lee Wei-liang (李威良), an assistant research fellow at the RCEC, says that as concerns grow about the effects of global warming, many countries are investing in the development of sophisticated models to improve the accuracy of climate change predictions. The purpose of the LCCR is to build Taiwan’s capabilities in the areas of climate modeling and simulations.
So far, more than 20 climate models have been developed globally, and there is considerable consensus among scientists that the models are critical tools for understanding the behavior of the planet’s atmosphere, climate and oceans. Crucially, the models can provide valuable insights into the changes that are occurring due to human activities, natural variability or interplay between the two. “The LCCR serves as a hub of climate change research in Taiwan by bringing together experts in the field. Using academic and government resources, we aim to develop a climate model to facilitate accurate projections,” Lee says. “Our ultimate goal is to build a suite ranging from low-resolution global earth system models to high-resolution regional models.” The team’s research interests encompass changes in extreme precipitation due to global warming, the East Asian and Indian summer monsoons and El Niño Southern Oscillation.
Two students from National Taiwan University collect data for their climate change research at a tea plantation in New Taipei City, northern Taiwan. (Photo courtesy of Global Change Research Center)
The LCCR has adopted climate models developed by two US-based institutions—the Community Earth System Model (CESM) from the National Center for Atmospheric Research (NCAR) and the High Resolution Atmosphere Model (HiRAM) from the Geophysical Fluid Dynamics Laboratory. The models are run on computer clusters in Academia Sinica and the National Center for High-performance Computing, which is located in the Hsinchu Science Park in northern Taiwan. CESM simulations are for long-term climate variability examinations, while HiRAM simulations are for high spatial resolution analysis.
Most climate models, Lee says, cannot simulate typhoons very well due to their low spatial resolutions. Hence, the LCCR uses HiRAM simulations to analyze typhoon characteristics such as geneses, intensities and tracks. Tentative results show that the number of typhoons seems to be falling, while the average intensity of the storms is increasing.
Scientists at the LCCR have collected a huge amount of data from several global climate models and built an online database to share simulation results with the domestic research community. In addition, Lee notes that the laboratory organizes international conferences featuring prestigious keynote speakers from home and abroad and closely cooperates with NCAR. CCliCS researchers travel to the United States to attend CESM workshops and NCAR scientists visit the RCEC to give tutorials and exchange ideas and information.
Projects such as CCliCS would not be possible without the efforts of the nation’s top universities. NTU helped spearhead climate change education and research in Taiwan by establishing the Global Change Research Center under its College of Science in 1992. The center offers courses and conducts basic research, with a special focus on issues concerning Taiwan and Southeast Asia. Lin Jiun-chuan (林俊全), the director of the center, says the fact that it was founded more than 20 years ago demonstrates that domestic scholars have been aware of the need to address climate change for some time.
In the years since the center was established, many countries have experienced an alarming increase in the frequency and magnitude of natural disasters. Extreme precipitation events are increasing in many areas, dangerous heat waves are becoming more common, and sea levels are rising. These events intensify political, economic and social pressures. “As an island nation, Taiwan is especially vulnerable to the effects of rising sea levels,” Lin says. “Today, our center feels an even more pressing obligation to help our country cope with these challenges by cultivating research talent and using our knowledge to assist policymaking on climate change.”
The director says more resources should be devoted to climate change education at universities, which he believes should be interdisciplinary and holistic. Currently, his center offers educational programs in three major fields—earth system science, energy technology and sustainable resources—and invites professors from a variety of disciplines such as atmospheric sciences, engineering, geography and public health to teach courses. The center’s programs are designed to increase students’ sensitivity toward the potential impacts of climate change and equip those who are interested in pursuing a career in climate change analysis with the know-how required.
The Taiwan Climate Change Projection and Information Platform website (Photo courtesy of Ministry of Science and Technology)
Information Platforms
Likewise, Chen Cheng-ta (陳正達), a professor in the Department of Earth Sciences at NTNU, emphasizes the importance of interdisciplinary approaches to climate change education. His department consists of some 20 faculty members from the fields of astronomy, atmospheric sciences, geology, geophysics and oceanography. Research forms a key aspect of the department’s work and many of its professors participate in projects initiated by the government or research institutions. For instance, Chen takes part in the Taiwan Climate Change Projection and Information Platform (TCCIP), which was launched by the NSC in 2010. Participating researchers collect historical climate data about Taiwan concerning humidity, precipitation, sea levels, temperature, typhoons and wind speed, analyze variations in the data over time and develop statistical methods to quantify expected changes to the region’s climate.
In recent years, Taiwan has focused its climate change mitigation efforts on encouraging efficient energy use and reducing carbon footprints. However, Chen notes that preparing for the inevitable effects of climate change is of equal importance, and that designing adaptation initiatives requires an understanding of future climate patterns. The TCCIP project, the professor explains, aids decision-making on climate change mitigation and adaptation measures. It is hoped that the information platform can have practical applications in diverse areas ranging from agriculture, homeland security and land use planning to public health and water resources management. “We need to identify likely future risks such as droughts, floods and heat waves so we can take action to prevent or minimize the damage they may cause,” he says. “Early and well-planned adaptation programs save lives and money later on.”
For every country, and particularly island nations such as Taiwan, climate change is no longer an abstract concept but a major factor that affects government policy in a huge number of areas. In order to properly inform decision-makers, a wide variety of studies will have to be done that map everything from the global ramifications to the region-specific consequences of a warming world. In this regard, Taiwanese scientists have already achieved significant results with their work on precipitation levels and sunshine duration. Furthermore, projects such as the TCCIP and the climate modeling research conducted by the LCCR will help further understanding of how climate change is affecting the nation.
Local scientists are passionate about sharing their work and are hopeful that their research and educational efforts can help guide measures to tackle global warming. “Academics and researchers feel a strong sense of mission to increase our understanding of climate change through interdisciplinary collaboration, and to motivate and empower individuals and organizations to take effective action,” Liu says. “Moreover, it’s our hope that by sharing our knowledge with the international scientific community, we can contribute to climate projections on a global scale.”
Write to Kelly Her at kher@mofa.gov.tw