Bulletin No. 1, 2016

What a University Can Do about Climate Change 7 Winner of United Nations’ World Meteorological Organization (WMO) Research Award for Young Scientists 2015 Prof. Amos Tai on Air Pollution, Climate Change and Food Security Prof. Francis Tam on Intensified Precipitation Prof. Lin Liu on the Thawing of Permafrost ‘ T he Ea r t h’s po l a r r eg i ons have been undergoing intense warming in the past decades as a result of global climate change. Permafrost thaw causes ground subsidence, which dis turbs the sur face vegetation and increases the risks of damaging infrastructures such as buildings and roads. More importantly, scientists recently found that permafros t in fac t s tores a large amount of organic carbon (about twice of the carbon in the atmosphere). Upon thawing, permafrost carbon decays and is released into the atmosphere as carbon dioxide and methane. These strong greenhouse gases aggravate atmospheric warming and affect the global climate. ‘However, many details about p e r m a f r o s t t h a w r e m a i n unknown: Where and how fast is the thaw occurring? Where and how fast does ground surface subside as a cons equence? How much permafrost carbon is being and will be released? In my research, I am trying to address some of these questions with a focus in the Arctic and the Tibetan Plateau.’ ‘In collaboration with the Hong Kong Obser vator y, my team ha s inve s t i ga ted how hea t released from human activities (Anthropogenic Heat, or AH) might affect the local rain rate, by carrying out a set of computer simulations for an ex treme rainfall event. ‘The extreme event took place in Hong Kong and the Pearl River Delta region in June 2008, when a record-breaking rain rate of over 140mm/hour was measured at the Hong Kong Observatory headquarter—the highest rain rate per hour ever recorded in the same location since 1885. We found a high correlation between precipitation rate and AH. The correlation, however, is less strong in non-urban areas. Results of our research have been published in an article entitled ‘Sensitivity of urban rainfall to anthropogenic heat flux—a numerical experiment’ in Geophysical Research Letters (March 2016). ‘In our recent study entitled “Threat to future global food security from climate change and ozone air pollution”, we found that global warming alone will reduce global crop production by more than 10% by t he yea r 2050, bu t t he combined effect of warming and intensified air pollution can be even more detrimental to agriculture. In the worst-case scenario, the undernourished p o p u l a t i o n i n d e v e l o p i n g countries can increase by 50% by 2050 due to global warming and air pollution. ‘ Ou r r e s e a r c h s h ow s t h a t s t r i n g e n t c o n t r o l o n a i r pollution, in addition to having tremendous health benefits, can partially offset the adverse impacts of climate change on agriculture. Our s tudy also implies that strategies tackling air pollution, climate change and food insecurity should be more integrated and there should be greater collaboration among scientist s and polic ymakers across disciplinary boundaries to help develop solutions for global health issues and food crisis.’