Managing Changes
Monsoonal Heatwave Variability Under Climate Change Scenarios Over Malaysian Peninsular Region: Heatwave and Climate Change View Digital Media
Paper Presentation in a Themed Session Justin Sentian
The aberrantly hot weather in the tropic over an extended period has increased the intensity and frequency of heatwave events. The potential risks from tropical heat waves due to intensifying future climate change are eminent and alarming, and therefore it is necessary to effectively assess the exposure risks to the general population and the magnitude of impacts under future climate change scenarios. By using the diagnostic output from Weather Research and Forecasting (WRF) model, climate change scenarios were developed, and the risk exposure of heatwave was analysed for the mid-century (2050) and end-century (2100) for the Malaysian Peninsula. Heat Index (HI) and heatwave risk exposure were calculated under RCP 4.5 and RCP 8.5 climate change scenarios, and potential hotspot areas of high-risk heatwave exposure were identified. Under RCP 4.5, the projected HI was in the range of 22 °C to 29 °C (2050) and 22 °C to 30 °C (2100), with further enhancements of 22 °C to 31 °C (2050) and 24 °C to 36 °C (2100) under RCP8.5. In both climatic scenarios, the region's HI would change by 1.1°C to 1.9°C in the mid-century and -0.4°C to 5.1°C at the end of the century. In both climate scenarios, heatwave occurrences were projected to occur more commonly during the summer monsoon (July) than during the winter monsoon (January). Our analysis also finds that the region's coastal and most urbanised areas are hotspots for greater heatwave indexes under climate change scenarios.
Daily Trends of Extreme Precipitation over the State of Rio de Janeiro, Brazil (1971-2020) View Digital Media
Paper Presentation in a Themed Session Lucí Hidalgo Nunes
Rio de Janeiro, a tropical and densely populated state in Southeastern Brazil, has been recording severe impacts associated with heavy rain such as flooding, erosion, storm surges and landslides. Since this scenario might get worse if rainfall becomes more concentrated, the study evaluated recent trends of daily rainfall in the region. The database consisted of 42 stations for a homogeneous period of 50 years (October 1970- September 2020, P0), pointing out geographical differences and changes in two subperiods compared between them: P1 (Oct.1971 - Sep. 1995) and P2 (Oct. 1996 – Sep. 2020). The Concentration Index (Martin-Vide, 2024), which identifies the participation of the most exceptional occurrences in the series was used to determine the degree of regularity of the rainfall distribution. Further analyses at annual level provided complementary information on the distribution of rainfall. Results show that over the 50 years there was no substantial change in annual rainfall totals, but there has been a general trend in the concentration of rainfall, i.e. very high volumes on a single day, as well as annual maxima that tend to be higher in recent years. Given the recent history of catastrophic events in the state of Rio de Janeiro, the results are a relevant element for natural disaster management.
The Hydro-wind-solar Energy Reactions to Geopolitical Stress: The Role of Global Environmental Governance
Paper Presentation in a Themed Session Refk Selmi, Ghada Haddad
The main purpose of this study is threefold. Firstly, it conducts an event study methodology to assess the responses of renewable (hydro, solar and wind) energy sectors to geopolitical risks. Secondly, a multifractal fluctuation analysis is used to test the efficiency of these industries in stressful times. It accounts for irregularities that may be embedded in the renewable energy industries’ behaviors. Thirdly, a wavelet coherence is employed to investigate the role played by global environmental governance (GEG) in crisis periods and under different time-horizons. Our findings reveal that rising geopolitical risks has led to an increase in the systematic risk for the three renewable energy sectors. In addition, significant changes in the properties of hydro, wind and solar are observed at various scales of time, highlighting their multifractal behaviors. Solar and wind energies become less efficient in the downward periods. Medium-to-high comovements across the GEG each renewable energy (with the exception of wind) as the warmer colors dominate all significant regions. The implication is that the pricing and returns generating process existing in hydro and solar power are heavily driven by global environmental governance. The inefficiency of solar power in crisis periods despite its strong connection with the GEG may be attributed to the fact that the environmental policies and the associated actions can generate significant uncertainties, leading to a new source of risk that can affect investment decisions and the performance of renewable industries.
