Changes In Climate in Asia Over The Past 100 Years

11/17/20222 min read

“The Asia Pacific region (Figure 1) is regarded as the most disaster-prone area of the world. Since 2000, 1.2 billion people have been exposed to hydrometeorological hazards alone through 1215 disaster events. It accounts for 91%, 92%, and 66% of global human exposure to tropical cyclones, floods, and landslides, respectively, on a per capita basis. Almost 2 million people were killed in disasters between 1970 and 2011, representing 75% of all disaster fatalities globally.” (Hashim, 2016)

Evidence of Changes in Climate

The most noticeable changes in climate, as observed in Asia, are rising sea levels, more intense and frequent heat waves, and more frequent and intense rainfall. In the Philipines, Perez et al (1999) observed that the annual mean sea level observed at the Manila Tide Gauge Station had risen by almost 50cm between 1948 and 1992. According to the World Meteorological Organization (2022), “the frequency of warm extremes over India has increased during 1951–2015, with accelerated warming trends during the recent 30 year period 1986–2015 (high confidence).” Researcher Phong Tran, working with several Vietnamese cities, remarked in 2018 that rainfall in that region “increased significantly” in the past 20 years (IMF, 2018).

Uncertainties

Generally, there are a number of uncertainties in studying climate change. There could be multiple factors responsible for one climate event. Hashim (2016) noted that “[a] single extreme weather event cannot be solely linked to anthropogenic climate change”. Indeed, in the case of the Manila Bay, although “the rising sea level observations are not believed to be the result of land subsidence”, it is a known fact that Manila is below sea level and sinking, potentially independent of climate change, and nearshore areas often become shallower due to soil erosion, siltation, and other causes (Perez, 1999). “Even without climate change, the areas prone to inunudation due to the 0.3 m sea level rise have been reported to suffer flooding during high tides.” (Perez, 1999) Additionally, in the case of the study of heatwave trends, matters are complicated by the fact that “[there] is no universally accepted definition of a heatwave amongst scientists. Rather, different regions measure heat events based on an appropriate historical baseline.” (UNDRR, 2022)

Comparing Recent Trends with Results of Longer-Term Studies

It appears that recent trends corroborate the result of longer-term studies. After analyzing core samples of mud from the Bay of Bengal, Professor Steven Clemens of Brown University confirmed that “over the past million years increases in carbon dioxide in the atmosphere have been followed by substantial increases in rainfall in the South Asian monsoon system” (NYT, 2021). This appears to align with the conclusions of a study conducted in 2021, which also suggested that “global heating caused by greenhouse gases, and the increased moisture in the warmed atmosphere, will result in rainier summer monsoon seasons and unpredictable, extreme rainfall events” (NYT, 2021).

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