A mémoire of Prof. Mikhail Ivanovitch Budyko
Introductory remarks by Dr H. Taba
Prof.Mikhail Ivanovitch Budyko was the 10th recipient of the Horton Medal, which is awarded for outstanding contributions to geophysical aspects of hydrology. The stimulation given by his original research to successive generations of hydrologists intent on treating hydrology as an Earth science was invaluable. Prof. James C.I. Dooge (Ireland), a well- known hydrologist said:
When I testify to the influence of Budyko’s books and papers on my own thinking, I know that I place myself in good company, which includes such names as Pete Eagleson, who introduced global thinking into the heart of hydrologic theory and Syuki Manabe, who introduced the land phase of the hydrological cycle into climate models. Budyko concerned himself with the interrelationship of moisture and heat fluxes with vegetation systems and ecology.
I had always heard of Budyko’s reputation as one of the best climate experts but I was surprised to learn that his scientific interests included not only climatology but also bioclimatology, palaeoclimatology and geochemistry.
Some years ago I had plans to interview Budyko for inclusion in the WMO Bulletin interview series. I had several contacts with him by telephone and we discussed the type of questions which I would like to ask him. Unfortunately, he died in December 2001 before I could see him. It was regrettable that I had not had the opportunity to put on record some of the reminiscences of such a great scientist for the readers of the WMO Bulletin.
Having discussed the matter with all concerned, it was agreed that we should instead prepare an article in memory of Budyko. To do this, I went to St. Petersburg in November 2002 and visited the State Hydrological Institute (SHI) and the Main Geophysical Observatory (MGO). I had discussions with some of the scientists who had known Budyko well and collaborated closely with him. It was agreed that each of these scientists would recount his or her own story about Budyko. Their thoughts are presented in the following pages.
During his long scientific life, Budyko published more than 300 original works including 12 monographs. His works have been translated into five languages.
In recognition of his outstanding scientific achievements, Budyko received the following awards: the Lenin Prize of the Soviet Union; the Prof. Lethke Gold Medal of the Soviet Geographical Society, the Voeikov and Vinogrsadov Prize of the Russian Academy of Sciences, the Prof. R. Horton Medal of the American Geophysical Society and the International Meteorological Organization (IMO) Prize of WMO. In 1988, he was awarded the International Blue Planet Prize for his contribution in the field of environment. He became an Academician of the Russian Academy of Sciences in 1992.
I wish to take this opportunity to thank all the contributors to this mémoire. I am also grateful to Prof. Valentin P . Meleshko, Director of the MGO for chairing and assisting our discussions.
Introductory remarks by Prof. I.A. Shiklomanov, Director, SHI
My association and collaboration with Prof. Budyko date back to 1976, when he became Head of the Institute’s Climate Change Department. At that time, I was Deputy Science Director. In 1981, I was appointed Director of SHI and as such was in close and constant contact with Budyko. I felt proud that such a great scientist was the Head of a Department in our Institute. In 1990, we both took part in the Second World Climate Conference in Geneva. We met many eminent foreign climatologists and virtually all of them called Budyko the “father” of global warming. I recall that one of those scientists told me that Budyko was a phenomenon in science and among scientists. Budyko not only predicted global warming—he also saw it happen during his lifetime. Budyko is known all over the world as a great climatologist. However, not many people knew the importance of the role he played and the valuable services he rendered to the field of hydrology, in particular in studies related to the water balance of river basins. His work on evaporation from land masses and on evaporation calculation methods using water- and heat-balance equations is well known among hydrologists. This approach, developed by him in 1948 and later on expanded and completed by L.I. Zubenok, is still widely used by hydrologists in calculating the water balance of rivers and watersheds as well as in models of river flows. In the 1980s, when the Institute started to study the problems related to anthropogenic climate change, Budyko drew attention to the following two main issues:
• The impact of climate change on the hydrological regime and on water resources;
• The possible repercussions and consequences for agriculture.
He realized that, unlike the other effects resulting from changes in the precipitation pattern and temperature, an alteration of the hydrological regime of water bodies, water resources and water usage would have immediate consequences with no time lag. In many regions of the world, in particular those with acute water problems, these consequences could be adverse and disastrous. For many years, Soviet Union and United States scientists worked together to tackle problems related to environmental protection (Working Group VIII). The Group paid particular attention to the impacts of anthropogenic climate change on water resources. Budyko was a USSR co-chair of that Group throughout its existence. Together, United States and USSR scientists produced a report entitled Prospects for Future Climate and Climate Change, which was published in 1990 in two languages. The report contains the findings of research conducted in the USA and USSR. Perhaps the most important role played by the Group was to foster extensive research pertaining to the problem of climate change and water resources—a problem which, at this stage, in the opinion of many, is the most urgent issue related to global warming. It is certainly in large part thanks to Budyko that it has become the focus of so much attention.
Budyko was a member of the old Russian scientific intelligentsia. He had an extraordinary broad field of interests: he was a top-notch scientist in climatology and hydrology; he was a master of history; he wrote popular books about unusual events and world history, containing the very best of popular, scientific and technical literature. His books often received awards and never lay on the shelves at bookstores for very long. He had a profound knowledge of and love for modern literature. He had personally known the great Russian author and poet Anna Akhmatova and wrote some interesting literary mémoires about her, published in a Russian literary journal. He adored English detective stories, especially those by Agatha Christie. He read them in the original language and kept an extensive collection of her books.
One of the most significant qualities of Budyko was his extreme modesty. He was wise, thoughtful and sociable. I am for ever grateful to him for his support in performing my duties as a Director. I needed that support since I was relatively young and inexperienced. I will always remember him with thanks and appreciation.
Recollections by Prof. Mark Berlyand, Main Scientist, MGO
Budyko was born on 20 January 1920 in Gomel, Belarus. He moved with his parents to Leningrad in 1929. In 1937, he completed his secondary school and entered the Leningrad Polytechnic Institute (LPI). His father was a lecturer at LPI until his retirement and his mother was a senior teacher there as well. His brother completed a postgraduate course at the same Institute and his aunt on his mother’s side was also a mathematics teacher at LPI. It was these close family ties which prompted Budyko to enter the Institute, although he was more interested in studying the humanities. Indeed, his penchant for the humanities continued throughout his life. Finally, he chose to study natural sciences. At school and at the LPI, he demonstrated exceptional abilities. He hardly played any sports, but he loved to play chess. Many of the city’s best chess players knew one another. World War II interrupted his studies after his fourth year at LPI and this was perhaps the main reason for his entering the MGO. The War and the Leningrad blockade brought enormous starvation. Budyko was evacuated with his family to Sverdlovsk (now Ekaterinburg), where he met M.I. Yudin, a chess companion and a talented scientist from the MGO. Yudin was only 28 yet he was already one of the greatest specialists in dynamic meteorology and had been assigned the task of creating a Department of Military Meteorology at the MGO. He asked Budyko to join the Department, combining his work with completion of his university studies. The newly created Department also employed some other young people who were at Sverdlovsk, among them V.S. Shevelyova who had already defended her dissertation before the War as a candidate of biological sciences. She and Budyko became friends and they married in 1947. She later defended her doctoral dissertation and was subsequently awarded the prestigious I.P. Pavlov Prize. She died in 1986.
Soon after Budyko, I entered Yudin’s Department at the MGO. I had already completed my studies at the Physics and Mathematics Faculty of Sverdlovsk University after being evacuated from Kiev. At the MGO, both Budyko and I were first assigned to the posts of senior technicians. In June 1942, having passed the State examinations at the university, we were transferred to engineering positions and were given independent assignments.
At the Observatory
The Observatory was the country’s oldest meteorological institution. We did not have the necessary meteorological training usually provided by specialized educational establishments but that was not a serious obstacle as we set about our work, perhaps because the tasks undertaken by the new Department were defined by the fact that a war was on. The assignments were to a certain degree, therefore, quite different from the research traditionally done by the Observatory in previous times. Meteorological expertise came to us gradually as we carried out our work. From the outset, the Department sent expeditions to validate its theoretical research and to define relevant parameters. To a great extent, the fact that we took part in them helped us to grasp meteorological concepts effectively.
We were right away assigned to work together on a scientific project. From the very beginning I was amazed that Budyko proposed to take responsibility for the physics and to allow me overall responsibility for the mathematical part of the assignment if I wished, although he was perfectly capable in mathematics. I remember this because, in his future research, Budyko, who had a great deal of intuition in physics, would pay more attention to the essence of the problem at hand and relied as little as possible on mathematics.
We were soon given separate assignments at the Observatory, but we went on expeditions together. Budyko studied soil evaporation influenced by boundary layer turbulence. His knowledge of aerodynamics gained during his studies at LPI helped ensure the success of his work. I was assigned to study smoke-diffusion modelling. In our first joint expedition near Sverdlovsk, in the summer of 1942, Budyko carried out experiments with small soil evaporimeters. At that time, I was studying the turbulence characteristics of the boundary layer, using observation data on the expansion of smoke streams from smoke bombs. The results we obtained served as the basis for our first publications in scientific journals.
Interestingly enough, the way our work developed eventually had a decisive influence on our future research. Immediately after beginning work at the Observatory, Budyko decided on his future specialization. He also strongly influenced my own decision, although I had other plans. Having ended up at the Observatory during wartime, I thought my free time there would be limited, so I wanted to return to my university specialization in theoretical physics. During my first years at the Observatory, I still kept books on quantum physics on my desk. But one day, early in 1943, Budyko proposed that we should both take the “candidate examinations” that were required to defend a dissertation as a candidate of sciences. He convinced me that it could be very useful to our future scientific work. In two months we passed four candidate examinations, one of which was in general meteorology and the other in theoretical meteorology.
In the spring of 1944, after the Leningrad blockade was broken, Budyko and I were invited to be the first people from the Observatory to return from Sverdlovsk to Leningrad. A few months later we were followed by others. By then, Budyko had completed his candidate dissertation and defended it at the Physics and Technical Institute. By the end of 1944 I had also presented my dissertation, and afterwards there was virtually no question of changing my speciality. Over the next three years, Budyko prepared his doctoral dissertation on the basis of his extensive research into boundary-layer turbulence and the development of an original model for it. It was published in 1948 as a monograph entitled Evaporation in Natural Conditions. A study of evaporation as a component of the boundary layer heat balance served as a basis for his further investigation of the heat balance at the Earth’s surface. Our work at the Observatory also had a decisive influence on my own subsequent research into the modelling of atmospheric pollution diffusion.
Soon after defending the physical and mathematical science doctoral dissertation, Budyko was appointed Deputy Director of the Observatory, and in 1954, Director. At the helm of the Observatory until 1972, he was able to raise the scientific level of the research done there and to keep it up to date, while at the same time boosting its stature both domestically and internationally.
Meteorology of the boundary layer
A major part of Budyko’s initial publications was devoted to the meteorology of the boundary layer. That subject was also central to his monograph entitled Evaporation in Natural Conditions. Many of his findings would remain topical for years to come, and he never lost interest in them. In 1958, he edited a collection of articles under the title Modern Problems of the Meteorology of the Boundary Layer.
Budyko’s formulas for defining the eddy coefficient were widely used for years and are still applied, in a partially modified form, in practical calculations. The boundary-layer stability index that he introduced, using the relationship between the temperature difference at two levels and the square of the wind velocity, was extensively used. The symbol assigned in the Russian literature to this index, even by authors who were in disagreement with Budyko, has nearly always been a Russian capital B, the initial of his last name. It would be entirely fitting to call this index Budyko’s parameter or figure and to use the symbol Bu as is common practice.
Budyko and Yudin together produced some interesting findings on the definition of the equilibrium temperature gradient in the atmosphere. At first, this led to the conclusion that the planetary heat turbulence flow was directed toward the surface of the Earth, and not in the opposite direction, as had often been assumed up until that time. Their assessments and research into the equilibrium temperature gradient are still of great interest as studies turn to turbulence exchange at higher levels of the atmospheric boundary layer.
Budyko’s interest in researching the heat balance of the Earth’s surface was inspired in part by the work of F. Albrecht and others but, for the most part, stemmed from his research into the meteorology of the boundary layer. The methods he developed for modelling turbulence exchange in the boundary layer made it possible to assess two major components of the heat balance: the heat turbulence flow and heat loss owing to soil evaporation. His very first publication in 1948 included a chapter entitled “The heat and water balance of the underlying surface”, and was based on this work. It was the first time his assessment of worldwide mid-latitude values for components of the land-surface heat balance appeared in the literature.
Because Budyko proposed that my wife, T.G. Berlyand, should carry out the first work on the terrestrial distribution of heat-balance components for the underlying surface, I was able to follow the beginning of this work quite closely. T.G. Berlyand calculated the components of the heat balance for the European part of the Soviet Union. Soon, under the direction of Budyko and with the participation of a number of other researchers, a systematic study was undertaken of the global characteristics of the heat balance. The study required many years of observational data from the worldwide network of weather stations. T.G. Berlyand was given a number of questions relating to the definition of radiation-balance components, including the solar radiation recorded at actinometric stations. Budyko even called upon me to do the theoretical research into the long-wave components of the radiation balance. In 1955, with the results obtained, T.G. Berlyand and I published an article on how to determine effective Earth radiation, taking cloud cover into account. The findings were subsequently widely used. Extensive work on estimating evaporation from the underlying surface was done by Budyko, together with L.I. Zubenok.
After some years, a series of global maps was produced, showing heat-balance components of the Earth’s surface for each month and giving average annual values. In 1955, the Atlas of the Heat Balance of the Earth was published, edited by Budyko, as well as a monograph on the subject in 1956. In recognition of this work, he was awarded the highest State medal at the time, the Lenin Prize.
Work on the heat balance continued at the Observatory for many years. The initial calculations were perfected and an extensive range of data on the ocean surface was added. Research was carried out on the Earth-atmosphere heat balance leading, in 1963, to the publication of a new edition of the Atlas of the Heat Balance of the Earth. The findings of that research are still valid today. Thanks to the initiative of Budyko when he was Director of the Observatory, the WMO World Radiation Data Centre was set up there and is still in operation.
Budyko’s special expertise and style of work
He had a number of qualities that ensured his success. One was his phenomenal memory. It was as if he remembered nearly everything he read or heard, not only in science, but also history, literature and other subjects. He could recite names, dates of birth and death and other information about many well-known leaders, past and present, of Russia and many other countries. This gift was first noticed by those who were close to him. It became quite well known in the latter years of his life, after publication of his three popular science books: Time Travel, Riddles of History and Episodes of History. Anyone who reads these books can not help but be impressed by the author’s excellent memory and the exceptional breadth of his knowledge in the most diverse areas of the natural sciences, human history and literature.
From time to time, in order to take a break from his work, Budyko enjoyed reading the encyclopaedia, generally to look for errors. And he would find them. Sometimes he would find many, in particular in the 1970s edition of the Great Soviet Encyclopaedia. Many involved such details as peoples’ names, or specifics of their birth or death or their activities. He was later able to get his hands on what was then the latest edition (the 15th) of the Encyclopaedia Britannica, in which he also found a large number of inaccuracies. He described these encyclopaedia errors in the final outline of his book, Episodes of History.
Another quality was a capacity for speed reading. He quickly absorbed the content of the written page. In a few hours, he could devour an enormous tome. I remember that, in his younger days, his wife, sometimes with the help of friends, would try to check whether he could really read so fast. She would carefully read a book and then serve it up to him for a quick perusal. He would always be able to answer any questions about the text.
Budyko initially studied English at the Institute and, in the early years of his work, he generally limited himself to scientific literature. Soon after the War, when international scientific contacts became more common, a greater command of English was required. In a short time, he mastered the language sufficiently well that he could read books in English almost as quickly as in Russian. He was able to go through an enormous book in English in just a few hours.
Perhaps the most important talent of Budyko as a scientist was his exceptional intuition in the field of physics and his ability to comprehend the essence of complex natural processes. This was of course enhanced by his ability to read quickly and his tremendous memory, as mentioned above. He was thus often able to distil and retain for further analysis a large variety and quantity of information.
Budyko’s writing abilities and his capacity to express himself concisely and quickly in presenting his scientific findings also accounted for his considerable success. Of course, many great scientists and writers perfect and edit their published works. Like them, Budyko was a responsible author. However, as he himself noted, he had a gift for writing articles right away and from scratch. He knew how to set out his ideas briefly, concisely and accessibly, and could clearly communicate the essence of complex problems.
His ability to deliver clear and at times brilliant presentations and lectures was also of great help in ensuring his scientific success.
Research into climate change
Based on his research into the global distribution of the heat-balance components and an analysis and generalization of his findings, Budyko, with his intuition in the field of physics, came to the conclusion that, in certain conditions, even minor anthropogenic changes in the Earth’s radiation balance could result in significant climate change.
In the first phase, in the mid-1960s, he postulated that an increase in the aerosols content of the atmosphere and the resulting reduction of solar radiation could be one such factor. A number of Western scientists had had similar ideas. Budyko was quick to understand the importance of climate change and, under his leadership, a new research branch was started at the Observatory. At first, atmospheric turbidity was investigated, using data from actinometric stations. Z.I. Pivovarova was asked to take part and they made many important and interesting findings together.
Budyko paid particular attention to the possibility of climate modification and the growing influence of man-made heat sources. In the late 1960s, he focused mainly on assessing the impact on climate of atmospheric carbon dioxide increases that reduced long-range radiation from Earth while trapping incident solar radiation. Data from the Mauna Loa (Hawaii) weather station showing systematic increases in average annual carbon-dioxide levels were helpful in this endeavour. At the time, there was an increasing amount of international cooperation in climate change research, a field in which Budyko was a leader. He proposed a universally accepted model that made it possible to assess the impact of carbon dioxide on temperature increases on Earth and to define the impact of a number of feedback factors. His findings led to the conclusion that increases in atmospheric carbon dioxide played a dominant role in global warming. Despite their simplicity (the term “Budyko-type models” even appeared in the literature), those models presaged and complemented, for many years, many of the conclusions drawn up using more detailed models that took atmospheric circulation into consideration. At the same time, because of the extreme complexity of the question, Budyko understood the importance of such detailed models. In the early 1970s, when Budyko was still Director of the Observatory, the Department of Dynamic Meteorology began to take all factors into account in its climate modelling. That work has continued to the present day.
Towards the end of his life, Budyko himself was of the opinion that his calculations had somewhat exaggerated the warming effect, as they had taken only carbon dioxide into consideration. He felt that the model needed to be perfected because of the effect of atmospheric aerosols. He even proposed that I should take up that question, saying that he had the data that would be required. But he never had a chance to tackle the problem.
Prof. Nina Efimova, Head of the Laboratory of Climate Change Detection, SHI
When cooling was the dominant trend
In 1961, Budyko hypothesised that global warming was inevitable, owing to the effects of human activities. At that time, most climatologists believed that cooling would continue as part of the long-term natural climate oscillation, and expected stronger cooling in the 1990s. In putting forward his hypothesis of anthropogenic climate change in the first phase of his research, Budyko postulated that, in accordance with heat-balance theory, warming would take place because all energy used by humans is eventually transformed into heat, raising the atmospheric temperature. He estimated that the additional heat input would soon have a significant influence on local temperature increases in cities and in the more developed industrial regions. Over a period of 100 or 200 years, this would lead to a sharp increase in the air temperature of the entire planet.
From the beginning of the 1970s, the idea began to emerge that global warming would not take 100 or 200 years, but would be observed in the coming decades because of the increase in atmospheric carbon dioxide levels resulting from the increasing use of fossil fuels. That would strengthen the greenhouse effect and raise the average global surface layer temperature. In 1972, Budyko published his first quantitative prediction of the increase in the average global air temperature until the middle of the 21st century, which was drawn up on the basis of the expected increase in atmospheric greenhouse-gas levels. This forecast has since proved to be of great accuracy.
Anthropogenic climate change
In 1961, at his initiative, the problem of anthropogenic climate change was brought to the attention of the board of the Hydrometeorological Service of the USSR. It was decided that there was a need for systematic research on the effects of human activity on the global climate. That same year, Budyko held an all-Union meeting in Leningrad on anthropogenic climate change. As part of his research, Budyko published in 1972 his first realistic prediction of climate change at the end of the 20th and first half of the 21st centuries, which was brilliantly corroborated in the 1980s and 1990s. In the 1970s and 1980s, at Budyko’s initiative, a number of institutes in the Hydrometeorological Service and of the Academy of Sciences of the USSR were called upon to work on the problem of climate change. The need for a broad, multifaceted approach to the problem of natural and anthropogenic climate change stemmed from the multidisciplinary nature of the problem. The findings of these scientific institutions were discussed at regularly held national meetings, chaired by Budyko.
In 1975, Budyko headed the Climate Change Research Department of the SHI, which was the focal point for work on this subject. In the 1970s and 1980s, a series of scientific meetings on climate change were held in the countries of eastern Europe. From 1972 on, scientists from the USSR and the USA collaborated in a working group on the influence of environmental change on climate, (Working Group VIII). Budyko was the Soviet co-chairman. For 15 years, scientists from the two countries carried out research into the reasons and consequences of imminent climate change. The research findings were considered at joint working seminars, symposia and meetings of experts. A number of joint scientific works, conclusions and reports were published. This Soviet-American research was the basis for predictions of future climate conditions. In 1987, on the occasion of the Washington Summit between Presidents Reagan and Gorbachev, an unprecedented agreement was signed in support of joint research into global climate change, including the commissioning of a joint report on future climate. The report was prepared and published in 1991 under the title Future Climate Change. Beginning in the mid-1970s, various international organizations, including WMO, began to pay a great deal of attention to research into climate change and WMO established the World Climate Programme.
Prof. Irena Borzenkova, Head of the Laboratory of Climate Change Impacts, SHI
Carbon dioxide and climate change
Carbon dioxide plays a key role in climate change. This is because it is almost transparent for short-wave solar radiation but absorbs a significant portion of the Earth’s long-wave heat radiation. As a result, the greenhouse effect raises the air temperature near the Earth’s surface. Carbon dioxide reaches the atmosphere from the depths of the Earth. Much of this is spewed into the atmosphere during volcanic eruptions. The amount absorbed by the atmosphere varies widely over both long-term and relatively short-term periods, according to the variation in volcanic activity.
Using data on the rate of carbonate formation on land and in the oceans in various periods and data from volcanic deposits, Budyko and others drew up data on changes in carbon dioxide content over the past 570 million years. According to these data, there have been significant variations in atmospheric carbon dioxide content, whose values, in some geological periods, were 10 times greater than present values. A declining trend in the carbon dioxide level has been noted from the beginning of the Tertiary period (about 60 million years ago). In the opinion of many researchers, this is linked with a gradual decline of volcanic activity.
By comparing the atmospheric temperature change data from different geological periods as derived from various indirect sources (palaeobotany, palaeontology and isotopes, etc.) with the data on atmospheric concentrations of carbon dioxide for the corresponding periods, Budyko concluded that the carbon dioxide concentration had, in the past, a significant influence on global temperatures and thus on climate conditions. The warm periods corresponded with a high atmospheric carbon dioxide content and, when the level declined, so did the global temperature. Additional amounts of carbon dioxide are now being released into the atmosphere from the burning of fossil fuels (coal, oil and gas). Every year, about five billion tonnes of carbon dioxide are thus released, far more than the amount arriving from the Earth’s mantle and crust. Carbon dioxide generation from economic activities can lead to a significant change in the atmosphere’s composition, and thus to climate change.
Analogues for future climate
An analysis of present climate change, in particular of temperature change at different latitudes, and a comparison with data on changes in the chemical composition of the atmosphere in the past 100 years show that an increase in the concentration of greenhouse gases, especially carbon dioxide and methane, could have led to significant warming as early as the middle of the 20th century. An analysis of palaeoclimatic data makes it possible to state with certainty that, in the past, the warm periods corresponded to high concentrations of carbon dioxide and methane, and that their decline in the Tertiary period was one of the causes of the Pleistocene glaciation. In modern times, man is restoring the chemical composition of the atmosphere to one that was characteristic of the warm periods of the past. It follows that those periods can serve as analogues for future climate. The use of palaeoclimatic information may serve in an independent approach that can be considered together with model calculations in assessing future climate conditions.
The factors that define climate
• Variations in incident solar radiation attributable to changes in the Sun’s irradiance as a star (the “solar constant”) and to changes in the Earth’s orbit and in the transparency of the upper atmosphere resulting from volcanic eruptions or impact events (large asteroids or comets);
• A change in the composition of the atmosphere, and first and foremost in the carbon dioxide and methane levels;
• A change in the albedo level of the Earth’s surface;
• A change in the proportions of land and sea related to tectonic processes, and a change in the oceanic and atmospheric circulation and variations in the sea level.
Using various types of indirect data on Earth’s climate history, Budyko concluded that the composition of the atmosphere was largely responsible for determining the global cooling process during the Cenozoic period (i.e. in the past 65 million years).
Changes in atmospheric aerosol concentrations in the upper atmosphere resulting from powerful volcanic explosions could significantly reduce the solar radiation arriving at the surface of the Earth, thus lowering air temperatures. In a number of cases, this impact could even be catastrophic, for example when, in a relatively short period, a series of volcanic eruptions takes place and the aerosol content in the upper atmosphere exceeds the average by a high order of magnitude.
Mankind’s impact on climate in the past
As early as the late Palaeolithic period, human activity had a significant effect on the environment and could even cause environmental crises. The destruction of forests associated with the development of farming led to a marked decrease in the amount of forest cover, the extinction of various types of flora and fauna and a loss of topsoil, resulting in desertification and an increase in the amount of arid areas. In a number of Mediterranean countries, desertification associated with excessive land exploitation in a region that was particularly vulnerable to relatively minor climate changes, in particular in respect of precipitation, may be an example of such an environmental crisis.
Prof. Oleg Anisimov, Head of the Climatological Department, SHI
At the end of the 1980s, Budyko became interested in the effects that changing climate may have on permafrost. His interest in permafrost was driven largely by two factors.
First, there was general consensus that climate change would be most pronounced at higher latitudes. It was thus logical to consider that changes in the environment would be greatest in these northern regions, and that the permafrost would be affected most of all. Secondly, a significant part of our country is occupied by permafrost. Permafrost occupied about 50 per cent of the territory of the former Soviet Union, (in the present-day Russian Federation, it occupies 67 per cent of land, as the Newly Independent States are mainly to the south). There is a well-developed infrastructure in permafrost regions, which includes facilities associated with ore-extracting industries, roads and railways, pipelines, airport runways and power supply systems. Major cities, such as Yakutsk, Vorkuta and Norilsk, and ship terminals on major northern rivers and along the Arctic coast are located in permafrost regions. Warming, thawing and retreat of permafrost may have detrimental consequences for the infrastructure built upon it.
At first glance, it was apparently quite easy to obtain a qualitative picture of the climate-induced changes of permafrost. The higher air temperatures in both winter and summer would warm the frozen ground, causing deeper seasonal thawing. The southern boundary of permafrost would gradually be displaced to the north and its area would consequently diminish. The only question was how quickly this would happen and how it would occur in the various regions. This was the main thrust of the research begun 10 years ago, which continues to this day. According to current findings, the area of permafrost may decrease by 12-15 per cent in the next 50 years. Its southern boundary may be displaced a few dozen kilometres to the north and north-east. The temperature of the frozen ground will rise everywhere, and the depth of seasonal thawing will increase on average by 15-25 per cent, and in some regions by more than 50 per cent. Clearly, the thawing of permafrost can be detrimental to buildings and infrastructure in the north and may cause damage. It would be wrong, however, to consider that the effects of the warming would be all negative in the north. Climate change will significantly reduce energy expenditure for heating. According to the assessments carried out by Budyko’s Department, the heating period in the far north around the middle of the 21st century could be reduced by three or four weeks, and winter heating may thus be less intense. Even if the efficiency of heating installations and home construction remain the same, real energy costs may be reduced by 20-25 per cent, thus producing savings that will no doubt be welcome.
Prof. Igor Karol, Chief of Laboratory
Budyko was one of the few (and no doubt the only Soviet) scientists who pioneered the widespread use of the large volumes of climate data accumulated up until the second half of the 20th century for tackling modern problems affecting the Earth. As a result of the considerable work done at the MGO in compiling the Atlas of the Heat Balance of the Earth in the 1950s and 1960s, he set out a simple formula for the calculation of the outgoing long-wave radiation flow in the Earth-atmosphere system, and he used that formula in a simple equation of the energy balance for the Earth’s surface. This led to a well-known, simple and elegant equation for the energy-balance model of Earth’s climate.
Unlike the United States climatologist William Sellers, who at approximately the same time published a similar energy balance equation, Budyko used his equation to study the sensitivity of the Earth’s climate system to variations in the solar constant, i.e. the input and output of solar energy from the Earth’s surface. He was the first to establish the possibility of a “Snowball Earth” stable state, with attention to hysteresis in the reaction of Earth-surface temperatures to variations in the solar constant. At the time, the possibility of a “Snowball Earth” was considered unlikely. Nonetheless, more recent research by palaeoclimatologists has shown such a scenario to be quite possible in the distant past, as the Sun’s brightness is now known to have been significantly lower than at present. This is borne out by traces of ancient glaciers found in the tropics in Africa and South America. They would otherwise be difficult to explain. Budyko also paid special attention to such questions as applied climatology and the influence of the climate on man’s comfort and health, and the distribution of solar radiation for photosynthesis on the Earth’s surface.
An important study carried out by Budyko and his collaborators was the assessment of the volumes of aerosols that would have to be released into the stratosphere by high-altitude, supersonic transports in order to provide a partial screen against solar radiation. Such a screen should theoretically compensate for the greenhouse effect created by the increase in atmospheric carbon dioxide, thus counteracting the anthropogenic global warming repeatedly predicted by Budyko during approximately the same period. These assessments were carried out and published in the early 1970s by staff at the Observatory. It was estimated that such releases of aerosols would be realistic using the Concordes and TU-144s that were, and are still now, in service.