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HKO Calendar-Preface



Climate and Water


Looking back in 2021, extreme weather continued to rage the world. In Hong Kong, the first half of the year was exceptionally warm with a mean temperature of 23.3 degrees, a mean maximum temperature of 26.3 degrees and a mean minimum temperature of 21.3 degrees recorded at the Observatory from January to June, all ranking the highest on record for the same period. The unusually hot weather persisted in July. According to the global data released by NOAA’s National Centers for Environmental Information, the global mean surface temperature in July 2021 was the highest ever recorded since 1880. In the past year, extreme weather also affected different regions in the world. Heat wave struck North America and Europe successively in the past summer. Hill fires in many countries were hard to control owing to dry weather. On the other hand, Zhengzhou in Henan province of China suffered from record-breaking rainstorms, resulting in severe flooding. Meanwhile, several European countries including Germany, Belgium and Switzerland were affected by prolonged rainstorms. The flooding affected river basins and caused widespread damages.

The Summary for Policymakers (SPM) of the Working Group I contribution to the Sixth Assessment Report (AR6) "Climate Change 2021: The Physical Science Basis" released by the United Nations Intergovernmental Panel on Climate Change (IPCC) on 9 August 2021 clearly highlighted that widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere with more extreme weather had occurred. It is unequivocal that human influence has warmed the atmosphere, ocean and land. According to the SPM, the climate goal in the Paris Agreement of limiting global warming to 2°C within the 21st century may still be possible if deep reductions in global carbon dioxide and other greenhouse gas emissions occur in the coming decades. We must act immediately to mitigate the global warming through saving energy and reducing emissions!

Majority of the photos in the Calendar originate from the Community Weather Observing Scheme (CWOS). I hope these photos will encourage us to protect the environment and strive for disaster reduction.

The World Meteorological Organization (WMO) has set the theme of the World Meteorological Day on 23 March 2022 as “Early Warning and Early Action. Hydrometeorological and Climate Information for Disaster Risk Reduction”. Climate change increases the frequencies of extreme weather events, while droughts and torrential rain occurring in different parts of the world will lead to imbalance in water resources. To achieve disaster reduction, the WMO is devoted to facilitating world-wide co-operation in observations, research and services in meteorology and hydrology. The Observatory will continue to support WMO’s works and devote efforts to promote the awareness of climate change and extreme weather to the public, students and youths.

CHENG Cho-ming
Director of the Hong Kong Observatory