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Assessing the impacts of climate variables on long-term air quality trends in Peninsular Malaysia.

Zheng, Yijing; Ooi, Maggie Chel Gee; Juneng, Liew; Wee, Hin Boo; Latif, Mohd Talib; Nadzir, Mohd Shahrul Mohd; Hanif, Norfazrin Mohd; Chan, Andy; Li, Li; Ahmad, Norfazilah binti; Tangang, Fredolin


Yijing Zheng

Maggie Chel Gee Ooi

Liew Juneng

Hin Boo Wee

Mohd Talib Latif

Mohd Shahrul Mohd Nadzir

Norfazrin Mohd Hanif

Li Li

Norfazilah binti Ahmad

Fredolin Tangang


Climate change is thought to influence the composition of atmospheric air, but little is known about the direct relationship between these variables, especially in a hot tropical climate like that of Malaysia. This work summarizes and analyzes the climate state and air quality of Peninsular Malaysia based on selected ground-based observations of the temperature, precipitation, relative humidity, wind speed, wind direction and concentrations of PM10, O3, CO, NO2, and SO2 over the last 20 years (2000–2019). The relationship between the climate state and air quality is analyzed using the Pearson correlation and canonical correlation analysis (CCA) methods is employed to predict the degree of change in the future air quality under different warming scenarios. It is found that the Peninsular Malaysia mainly experienced strong precipitation in the central and mountainous regions, while air pollutants are primarily concentrated in densely populated areas. Throughout the period of study (interannual, monthly, and diurnal time series analyses), Peninsular Malaysia became warmer and drier, with a significant increase in temperature (+4.2 %), decrease in the relative humidity (−4.5 %), and greater fluctuation in precipitation amount. The pollution conditions have worsened; there has been an increase in the PM10 (+16.4 %), O3 (+39.5 %), and NO2 (+2.1 %) concentration over the last 20 years. However, the amount of SO2 (−53.6 %) and CO (−20.6 %) decreased significantly. The analysis of the monthly variation shows a strong bimodality of the PM10 and O3 concentrations that corresponds to the monsoon transition. Intensive diurnal fluctuations and correlations are observed for all the variables in this study. According to the CCA, the air quality factors are strongly correlated with meteorological factors; in particular, the CO, O3, and PM10 concentrations interact strongly with the air temperature. These findings show that the future air quality in Peninsular Malaysia has high possibility to deteriorate under warming condition.


ZHENG, Y., OOI., M.C.G., JUNENG, L., WEE, H.B., LATIF, M.T., NADZIR, M.S.M., HANIF, N.M., CHAN, A., LI, L., AHMAD, N.B., TANGANG, F. 2023. Assessing the impacts of climate variables on long-term air quality trends in Peninsular Malaysia. Science of the total environment [online], 901, article 166430. Available from:

Journal Article Type Article
Acceptance Date Aug 17, 2023
Online Publication Date Aug 20, 2023
Publication Date Nov 25, 2023
Deposit Date Aug 25, 2023
Publicly Available Date Aug 21, 2024
Journal Science of the total environment
Print ISSN 0048-9697
Electronic ISSN 1879-1026
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 901
Article Number 166430
Keywords Global warming; Temperature; Ozone; Canonical correlation analysis
Public URL
Additional Information This article has been published with separate supporting information. This supporting information has been incorporated into a single file on this repository and can be found at the end of the file associated with this output.