CUHK Passions and Pursuits

17 Heat Waves in Europe and China Europe China In the Past Late 21st Century In the Past Late 21st Century Duration (days per year) 11.7 16.0 12.3 26.6 No. of heat waves per year 1.9 4.3 1.4 3.6 No. of heat-wave days per year 22.6 69.0 17.0 95.9 2007 Nobel Peace Prize with former US vice president Al Gore , after the release of his climate-change documentary An Inconvenient Truth . ‘Unless we really take measures in limiting emissions and conserving energy consumption, global warming will continue,’ Professor Lau said. ‘More heat waves will follow suit.’ Feeling the Heat? Gabriel Lau warns of soaring temperatures T hanks to global warming, heat waves will triple in frequency and soon take up half the summer, according to the work of Prof. Gabriel Lau Ngar-cheung . The definition of a heat wave is that average temperatures rise into the highest 10% of their typical range and remain there for three or more days. The cause of a heat wave is a ‘dome’ of hot air that forms during very clear weather with more sunshine. The land becomes baked, and the dry conditions enhance ‘sensible heat’ that can be felt, as opposed to the latent heat associated with moisture. The heat-wave dome then holds at bay other weather systems. Research continues in an attempt to quantify, as surmised, the effect of remote processes in causing and extending heat waves. For instance, it is likely but not yet proven that a rise in sea temperatures in one part of the world can augment a heat wave in another part. Heat waves cause a significant number of deaths in their most severe form, particularly among elderly people. Heat waves also cause a very dry climate, and ultimately droughts. Agriculture suffers, and forest fires increase in frequency and magnitude. In the American West, there are now fire and drought emergencies virtually every summer. Professor Lau’s computer modelling indicates that heat waves will lengthen from the typical three to four days, to seven to 10 days. Instead of one per summer, there will be three or four. The combined effect is profound, meaning heat waves occur for more than 50% of the summer season in many parts of the world, instead of just a few days per year. Professor Lau has devoted his 40-year career to climate research, scouring through observational climate records and prediction computer models to ‘map’ the progress of climate variations and their likely future paths. Heat waves have been his specific focus for the better part of the last decade. North America was his original focus, but his gaze then shifted to Europe and then to Asia. The results are equally if not more alarming: ‘Global warming is so pervasive that all these regions will experience some increase in heat waves,’ Professor Lau said. He felt sure that examination of other parts of the world would lead to similar results: ‘Climate change has profound implications on the socioeconomic well-being of the entire global population.’ Professor Lau has played a prominent role in the work of the United Nation’s Intergovernmental Panel on Climate Change (IPCC). The panel combines the work of thousands of climate scientists around the world in the largest scientific assessment of climate change ever attempted. The IPCC, which was set up in 1988, publishes an assessment report every six to seven years. He first contributed to the 2007 report. Then as a lead author, Professor Lau helped draft the final chapter of the 2013 report. The panel shared the