Keith Alverson
(Inergovernmental Oceanographic Commission of UNESCO, )
I first met Liu Tungsheng in, of all places, the little town of Hilterfingen, Switzerland on the shore of Lake Thun. I had finished my postdoc at the University of Toronto only a few weeks earlier, and had just taken up a new position as ‘Science Officer’ at the PAGES (Past Global Changes) International Project Office. At the time I had only a vague understanding of the field of paleoclimatology, and an even dimmer understanding of what PAGES did. The director of PAGES at the time, Frank Oldfield, had asked me to give a presentation at this ‘Hilterfingen’ meeting which had brought together the many leaders of different PAGES projects around the world, and I had prepared to lecture to them on the importance of explicitly including both model and data uncertainty estimates when making model-data comparisons. In retrospect, even accepting the task of giving a presentation to this august collection of intellectual leaders in the field was certainly youthful hubris on my part. Although I doubt that any of the project leaders can remember my presentation (all in all probably a good thing) the meeting is certainly etched in my own memory. It was a kind of trial by fire, my first exposure to the heart of international scientific cooperation in the field of paleoclimate, and the first opportunity I had to meet the few dozen scientists at the forefront of this cooperation, one of whom was Liu Tungsheng.
At the time Tungsheng was the leader of the Austral-Asian Pole-Equator-Pole (PEP II) Transect, one of three such north-south transects launched by PAGES in the early 1990’s. The PEP II effort was, from its inception, led and co-ordinated from China and Australia through the work of Liu Tungsheng, and later his junior colleague Guo Zhengtang, together with John Dodson. These leaders coordinated workshops and colloquia at international meetings that provided the opportunity to bring researchers from the Asia-Pacific region together and consider the kinds of proxy evidence available in order to improve an understanding of environmental variability across the region. From the outset, the PEP transects had dual roles, each complementing and reinforcing the other. Firstly, they were frameworks within which research communities formed linkages across national and disciplinary boundaries. A key element of this community building process was the sense of inclusion, and contribution, that membership provided to otherwise sometimes isolated researchers in developing countries. At the same time, the transects were formulated around a series of shared scientific questions beyond the scope of an individual research group or even an individual nation.
Although reconstructing inter-hemispheric patterns of natural climate variability was the initial and primary focus of the PEP transects, there were shifts in perspective during their development. Partly as the result of the work Liu Tungsheng pioneered correlating Chinese Loess-Paleosol sequences with North Atlantic climate variability recorded in Marine Sediments – a correlation that was impossible to explain with atmospheric dynamics alone - there was a growing realization that climate must be understood within the context of a complex Earth System within which multiple feedbacks between atmosphere, biosphere, hydrosphere and cryosphere operate. At the same time there was also an increased recognition of the role of human activities in environmental change – a two-way process in which climatically linked environmental stress and societal responses interact with consequences for both the environment and human populations.
The vast area spanned by PEP II also included a huge diversity of environments, from tropical rain forests to arid continental interiors, from humid coastal lowlands to the highest mountains on Earth and from warm tropical seas to the permafrost and ice covered regions at high latitudes. Climate variability and environmental change have played a major role in the welfare of people across the region. All current indications are that their significance may be even greater in the future. The combination of high vulnerability to environmental hazards such as floods and droughts, and continuing rapid population growth leave parts of the region under serious threat from increased variability, extreme events and future sea-level rise. Climate variability affects human welfare in a variety of ways and on a range of spatial and temporal scales. Equally, as land cover and agricultural practices change in response to evolving human needs there are important feedbacks to the climate system. One of the lessons that Liu Tungsheng was most instrumental in teaching was that the palaeo-record holds vital clues as to these interactions. Improving the quality and long term security of water supplies, enhancing agricultural productivity and planning for the avoidance or mitigation of environmental hazards are all of high priority in the region. They require a good understanding of past variability, human responses and human-environment interactions.
Four thousand years ago Yu the Great, founder of the first, semi-mythical, Xia dynasty of China is said to have spent more than a decade battling floods continuously inundating the valley of the Yellow river. According to Confucius’ Shu Jing, written much later in the 5th Century BC but collated from ancient sources, Yu’s great insight was to stop relying on the practice of building ever-higher levees and dikes, and instead dig a vast network channels to drain the great volumes of water east to the sea. Flooding, up until the present day, has continued to be a major concern for the region. A million people are thought to have died when the Yangtze broke through flood defenses in 1877. But flooding is not the only problem; the flow of the Yellow River has been in continual decline for the last 50 years. In 1997, the river ran dry in places during 226 days of the year. Much of China’s agriculture and population depends on water from the Yangtze and is greatly vulnerable to drought.
The proposed modern day solutions, although multi-billion dollar engineering projects, are not so very different from those under discussion in the time of Yu. One, the famous Three Gorges Dam, in addition to generating electricity, is intended to control flooding. A second, intended to ameliorate vulnerability to drought, is to divert water to the north, primarily from the Yangtze river basin, by digging a series of south to north canals in the western, central and eastern parts of China. Will these gigantic engineering projects fulfill their goals? Will they reduce human vulnerability to climatic variability and change?
The answers to these questions are a matter of much debate, and I won’t even try to provide them here. Instead it is worth remembering one of the many lessons that Liu Tungsheng hammered home time and time again in his publications and presentations: that paleoenvironmental science, which is often neglected in such debates, provides a detailed, quantitative four thousand year record of human society, climate variability and their interaction in China. Such information from the past is directly relevant to questions of climate variability and human vulnerability and therefore relevant to the political decision making processes today. In fact, the very definition of flood magnitude used in risk assessment by modern insurance industry, the commonly used concept of the ‘hundred year flood,’ puts modern events in the context of the long term record. The record of long term variations is crucial to understanding modern changes. This message championed by Liu Tungsheng, that the past record is important to modern concerns, remains relevant today throughout the entire spectrum of global change research, and throughout the Asia-Pacific region. Paleoenvironmental research should be a vital component in any holistic study of ongoing changes in groundwater, landuse and landcover change, sea level, biodiversity, extreme climatic events, human vulnerability.
At our very first meeting in Hilterfingen, Tungsheng was pleasantly surprised to learn that I could converse in Mandarin and, from that day on, he was always very pleased to speak with me in Chinese despite the fact that his English was of course far more accomplished than my Chinese. In fact one of the things I enjoyed most about working for PAGES was that the Mandarin I had worked hard to learn could be used every now and then. But, the truth is Tungsheng and I only spoke Chinese when we were discussing quotidian matters, like the weather, or his opinion about the egregious excess of fat and potatoes in Swiss food, something Tungsheng was quite adamant about. Of course what I did not reveal to Tungsheng was that when I was speaking Bernese dialect with my Swiss colleagues at meetings in China, they showed a similar distaste for the strange and exotic ingredients in Chinese food. When the conversation turned from food to science we of course spoke English. I distinctly recall at one point – we were discussing the role of weathering in setting atmospheric Carbon Dioxide levels on geologic timescales – that Tungsheng mentioned ‘chelation’. Though quite proud of his wide and erudite scientific linguistic toolbox, he nonetheless looked at me queryingly for confirmation that he was pronouncing the word properly. Regrettably I was not of much help – I had no idea what he was talking about, and had to look it up myself later to learn that chelation is the process of extracting metal ions from minerals and rocks, often for uptake and accumulation into plants and micro-organisms. Of the many, many things that I later learned from Liu Tungsheng, it certainly is a surprise that one of the first was a little lesson in English vocabulary!
Some years later I was asked by the committee, who were awarding the prestigious 2002 Tyler Prize in Environmental Science to Wally Broeker and Liu Tungsheng, to write a brief letter of congratulations (figure 1) for Tungsheng. In doing this I looked a bit more deeply into some of his scientific research over the years and learned that he had been instrumental in helping diagnose selenium deficient soil in some regions of northeast of China as cause of the widely occurring, and easily treated once understood, occurrence of congestive cardiomyopathy caused by dietary deficiency in the mineral selenium. No wonder Tungsheng was familiar with the term chelation.
Over the decade that I interacted with Tungsheng, I traveled to China many times. Mostly these trips were to give talks at various international scientific meetings including the 4th International Conference on Asian Marine Geology (Qingdao, 1999), the 5th International Conference on Cenozoic Evolution of the Asia-Pacific Environment (Hong Kong, 2001), the 2nd Global Ocean Ecosystem Dynamics Science Conference (Qingdao, 2002), the International Symposium on Climate Change (Beijing, 2003), The joint 2nd Past Global Changes Open Science Conference and 9th International Association for Meteorology and Atmospheric Sciences Scientific Assembly (Beijing, 2005), and the 8th meeting of the Partnership for Observing the Global Oceans (Qingdao, 2007). It is of course always a great pleasure for me to travel to China since I recall with great fondness the time I spent studying at Beijing Shifan Daxue in 1984 and teaching at Nanjing Hangkong Xueyuan in 1988, but the most memorable and enjoyable aspect of these trips has always been the opportunity to rekindle old friendships. Often alongside these visits old friends have invited me to give talks at their institutes and we always find time to share common interests and memories over a cup of Longjing tea, Qingdao beer or even Maotai Jiu (which everyone knows I can’t stomach, yet insist on toasting me with anyway) while savoring my favorite pork and garlic green filled Guotie. Indeed, the greatest and most lasting gift I cherish from Liu Tungsheng is these many friends, including An Zhisheng, Guo Zhengtang, Ding Zhongli and Wu Guoxiong, whom I met through Tungsheng’s introduction and with whom I am able to continue to share fond memories of him and his love of science.
