World energy consumption 1800-2000: sources of information

The definition of representative data on world energy consumption (Read: World Energy Consumption 1800-2000: Definitions and Measurements) is one thing, the identification of sources of information allowing the reconstruction of statistical series over a long period for all regions of the world is another. What data are available? Some time series cover the energy consumption of all the countries of the world, but only for fractions of a time less than the long period 1800-2000. Others, which cover much longer periods of time, cover only a few countries. Many of these statistical data neglect the so-called non-commercial energy sources, notably biomass, which nevertheless predominate in the energy balances of most countries during most of the period studied. After identifying all these sources of information, it will therefore be necessary to reconstitute coherent time series covering all regions of the world over the entire period, based on those whose reliability seems to be proven (See: World Energy Consumption 1800-2000: Results)[1].

1. Long time series on a global scale

To our knowledge, the only statistical yearbook covering all the countries of the world, over a period roughly the same (1800-1985) as the one chosen here, is the one edited by Paul Bairoch and Jean-Claude Toutain[2]. The authors have assembled all known time series on the production of hard coal, browncoal, natural gas, crude oil and electricity, in specific units and then in tons of coal equivalent (tce). Unfortunately, the yearbook excludes imports and exports, which makes it unusable for the study of national and regional consumption, given the share taken by international fuel trade, and this from the first half of the 19th century for coal. The yearbook, moreover, ” for lack of sufficient statistical sources” (p. 21), does not include biomass, which nevertheless remained the world’s leading energy source until it was dethroned by coal a few years into the 20th century (Figure 1).

Fig. 1: Paul Bairoch (1930-1999) whose advice was invaluable to us. [Source: Wikipedia]

Are there other long time series that do not focus on the production of energy sources but on their consumption on a global scale? The availability differs according to the periods covered.

1.1. After the Second World War

As soon as it was created, the United Nations systematized the statistical surveys undertaken by the League of Nations in the 1930s. From 1950 onwards, annual data, published periodically, on primary consumption from commercial sources and, in part, on final consumption (petroleum products and electricity) are therefore available for all countries in the world.

These sources are treated, country by country, then region by region, on the basis of C = P + I – E ± stocks – bunkers. Subject to a modification of the equivalence coefficients, some different geographical breakdowns and some improvements made since 1970 by the work of the International Energy Agency (IEA), the United Nations series can be used[3].

But even during this period, the tracking of so-called non-commercial sources (mainly biomass) is not so simple. Since 1946, the Food and Agriculture Organization (FAO) has published an annual estimate of the production of forest products by country[4]. The quantitative insignificance of international trade in fuelwood, estimated in 1995 at 0.2% of production, makes it possible to equate production and consumption. Unfortunately, the FAO data do not include fuelwood collected by villagers in developing countries, who are by far the largest users of this type of fuel, nor do they include waste products such as dried animal excrement or residues from the sugar industry, which together can account for 10 to 20% of the energy consumption of countries as large as India or Brazil. Other organizations[5] have attempted to fill these gaps (Table 1).

Table 1: Biomass energy consumption statistics

See the meaning of the units of account in World Energy Consumption 1800-2000: Definitions and Measures

The series published by the IEA since 1971 are intended to be more complete and explicit, at least for developed countries whose biomass is subdivided into solid biomass, gases and liquids from biomass, municipal waste and industrial waste. Those published by the United Nations from the same date are structured on a basis better adapted to the situation of developing countries (fuelwood, bagasse, animal waste, plant waste and other waste). By region and by country on a global scale, these latest time series are the most interesting, but their connection with the previous FAO series is difficult[6] because, in addition to the differences in biomass content, the units of account and their equivalences vary[7]. A strong break thus occurs in the FAO series between 1960 and 1961 following a modification of these two parameters. We will see later how we can try to overcome these difficulties.

1.2. Before the Second World War

To our knowledge, the only energy consumption series for all countries in the world are those compiled by Joel Darmstadter and his colleagues at Resources for the Future[8] but they are limited to a few years: 1925, 1929, 1933, 1937 and 1938, for the period before 1950. They come from a remarkable compilation of all available sources, both national and international: League of Nations; WorldPower

Conference; International Union of Producers and Distributors of Electrical Energy (UIPEDE). Converted into tons of coal equivalent (tce), on the basis of standard coefficients, the data by source are very easily reconverted into toe, while the regional groupings are easily adaptable to those we have retained, by adding Japan and the communist countries (China, North Korea, Vietnam) to the Asia region. However, the interest of these series is limited by their discontinuous nature and by their failure to take into account traditional sources (biomass). To complete them and go further back in time, we must therefore turn to the historical statistical yearbooks (Figure 2).

Fig. 2: Joel Darmstadter (b. 1928), tireless researcher at Resources for the Future. [Source: Resources for the Future]

For some countries and periods, these statistical series exist in national directories that could be referred to directly, but which B.R. Mitchell has fortunately compiled. The most numerous, the longest and probably the most reliable are those of the European countries, most of which have old national statistical services. The yearbook for these countries thus provides trends in the production, import and export of mineral coal, oil and natural gas since the 19th century[9]. The main limitation concerns electricity production, not because the series are not long (they go back to 1896 for the United Kingdom, 1900 for France, Germany, Spain and Sweden), but because they do not separate primary (hydro) and secondary (thermal) production, whereas only the former should be included in total energy consumption. Corrections must therefore be made, either from other series such as those in the Etemad-Luciani yearbook, which make the distinction, or from a good knowledge of the evolution of the fleets (totally hydro or totally thermal in some countries). On these bases, primary consumption from commercial sources could be reconstructed for Belgium (since 1831), Austria (1819), Denmark (1843), Finland (1860), France (1802), Germany (1817), Italy (1861), the Netherlands (1846), Norway (1829), Spain (1849), Sweden (1840), Switzerland (1858), the United Kingdom (1816), and Russia/the Soviet Union (1860).

For the rest of the world[10], B.R. Mitchell’s series do not allow us to go that far, but we can nevertheless reconstruct the commercial energy consumption of some countries from earlier periods: Argentina (1887), Australia (1851), Brazil (1900), Canada (1858), Chile (1895), China (1885), Colombia (1921), India (1890), Japan (1875), Mexico (1891), Peru (1884), and the United States of America (1850).

For some of these countries, it is also possible to compare the series obtained with the results of a few studies of the long-term evolution of energy consumption, one of them worldwide, most of them national.

2. The evolution of world energy consumption according to Palmer Putnam

One of the oldest and certainly the most ambitious reconstitution of world energy consumption since the 19th century was commissioned in the United States in 1949 by the Atomic Energy Commission (AEC), which wanted to know the maximum world energy consumption for the years 2000 and 2050 in order to outline the possible contribution of nuclear energy[11].

The exploration of the coming century, in the eyes of the author, was inseparable from that of the completed century, hence a careful examination of the evolution of world energy consumption between 1860 and 1947. With the exception of the so-called animate sources (muscular power of men and animals, which represents less than 1% of the consumption of the industrialized countries but a little more than that of the others), wind and solar energy (used in particular for drying fish and meat), consumption includes all sources of any importance, commercial and non-commercial, such as firewood, charcoal, peat, and animal and vegetable waste. It is estimated annually for Russia, including the Caucasus and Siberia (1860-1950); the United States (1800-1950); the United Kingdom (1854-1949); Japan (1915-1949); India (1878-1947); Germany (1860-1943); France (1909-1949); Argentina (1922-1940); and then for the world (1860-1950), by summing up the chronicles of each country increased by 1/6th, which is supposed to represent the rest of the world.

At the end of his study, Palmer Putnam concludes that world primary energy consumption increased between 1860 and 1947 (after converting the¹⁰¹² Btu he uses into Mtoe) from 94 to 1,648 Mtoe for commercial sources alone, and from 346 to 2,037 Mtoe for all energy sources. The margin of error, he points out, should not exceed 10% and is more in the range of 2-5% for recent annual data for countries with a long tradition of statistical records (p. 73), but is “indeterminate and speculative” for all other data (p. 327). A major source of energy in 1860 (75%), fuelwood no longer exceeded 20% in 1950, since it had been outstripped by mineral coal since 1880; the latter peaked in 1910 (88%) and then declined in turn to 50%, to the benefit of liquid fuels, whose contribution rose from 12% in 1925 to 30% in 1950.

At what rate did the world increase its energy consumption? Over the whole period, at an average annual rate of 2.0% for all energy sources and 3.3% for commercial sources alone. But these rates are misleading, comments Palmer Putnam, because they relate to the inputs of the system, i.e.raw energy, and not to its outputs, i.e. the quantities of useful energy (usefullenergy) at the final consumer. In order to pass from one to the other, theinput of each country and each year must be multiplied by the corresponding global efficiency, which is the sum of the technical efficiencies that follow one another between primary energy and useful energy[12]. These efficiencies are not only different from one country to another at the beginning of the period, but they also evolve differently, as can be seen in Table 2.

Table 2: Changes in overall efficiencies over the study period.

Taking into account the changes in these global efficiencies considerably raises the growth rates of actual energy consumption in each country. How can they be explained? Mainly by the evolution of the structure of energy uses, between low temperature heat (comfortheat), high temperature heat (processheat) and motive power (work). At the beginning of the period, the weak development of industry and non-traditional transport (draught animals and pack animals) made home heating the dominant use (more than 90%) with very variable efficiencies, from 35% with the Russian earthenware stove to 8% with the colonial open fire in the United States. Thereafter, two movements are combined. The efficiencies evolve differently: supposedly stable in Russia/Soviet Union, they rise to 50% in the United States with the central heating of buildings. With industrialization, the structure of uses changes: the share of high temperature heat increases from 5 to 10% and that of motive power from 0 to 50%. As the technical efficiency of motive power is on average lower than that of thermal uses, the increase in its share of total uses offsets the upward effects of advances in energy technology.

What is the value of Palmer Putnam’s reconstruction of world energy consumption? His comparison, country by country and source by source, with other estimates (which will be done later) provides useful reference points but reveals numerous anomalies: the inflated consumption of coal in the United Kingdom in 1880; the systematic underestimation of the consumption of petroleum products in the United States; the aberrant world consumption of natural gas in the 19th century when compared with that of the United States, which was practically the only consumer at the time; and the totally arbitrary estimate of the consumption of vegetable wastes….. However, the method used remains a model that should be used to take into account the impact of changes in use on the growth of primary energy consumption.

3. National studies of energy consumption over a very long period

In several countries, research on the very long-term evolution of energy consumption has led to the construction of long time series. Unfortunately, it is impossible to know them all, especially when their publication has remained confidential.

3.1. United States

Few years separate the publication of Palmer Putnam’s results from the launch of the great Resources for the Future study, under the direction of Sam H. Schurr in the mid-fifties[13]. As in the previous study, retrospection is at the service of foresight, but the latter has a shorter time horizon (1975) and goes much further into the details of consumption. In addition to the qualitative aspects on which the search for explanations of the exceptional growth of energy consumption in the United States is based (chapters 3, 5 and 7 in particular), Sam Schurr’s study includes several long series that are particularly valuable for reconstructing the evolution of world energy consumption since the beginning of the 19th century (Figure 3).

Fig. 3: The reference work on the history of energy in the United States. [Source: Amazon.com]

Over the period 1850-1955, the production of all energy sources is in annual data, in specific units[14] and in trillion (10⁹) or trillion (10¹²) Btu. Energy consumption is provided in identical terms, except for the periodicity, which is only five-yearly between 1850 and 1900 (pp. 508-13). Over the 105 years studied, it increases from 2,357 to 40,796 trillion Btu, or from 59 to 1,020 Mtoe. This average annual growth of 2.7% obviously masks the very uneven rates between sub-periods. Compared to Palmer Putnam’s series for the United States, the differences in total consumption are insignificant in 1949 (3.5%) but significant in 1850 (20%) because Sam Schurr’s estimate of fuelwood is insignificant in the same proportion. In terms of the structure of consumption by source, wood fell from 91% in 1850 to 2.6% in 1955, while solid mineral fuels, which were in the lead in 1886, were overtaken by hydrocarbons in 1947. While neither perfect nor definitive, these data are the best available for the United States for the period 1850-1950 (see: Mineral coal in the United States, the first steps of the industry).

3.2. United Kingdom

The study of energy consumption and its relationship with economic activity over a very long period has benefited from the age and excellence of the statistical sources of information as well as from historical works. William S. Humphrey and Joe Stanislas,[15] who present themselves as “economichistorians” (p. 29), know nothing of the statistical pitfalls of the very long period, but have not hesitated to cover 275 years, a record! After converting tokens into toe, their series shows consumption of commercial energy sources (including hydro) rising from 2.1 Mtoe in 1700 to 7.5 Mtoe in 1800, 115.9 Mtoe in 1900 and 223.8 Mtoe in 1975, i.e., an average annual growth rate of 1.7 percent over the entire period, 2 percent since 1800 and 0.9 percent since 1900. In relation to the growth of economic activity (GDP), the growth of energy consumption was only rapid between 1830 and 1870, a period of extensive restructuring, but it is probably overestimated by the exclusion of non-commercial sources.

Can we correct some of the shortcomings of this study and go further in explaining energy growth? Yes, say Roger Fouquet and Peter Pearson, who propose to gather and integrate existing data for the period 1800-2000, but also to build a picture of the factors that are at the root of the changes in energy use in the United Kingdom over a very long period[16]. The growth in consumption they arrive at differs little from the previous one (9.2 Mtoe in 1800; 117.5 in 1900; 270.0 in 1996, or 1.7% over the whole period), but its determinants are analyzed in more detail. In so doing, the authors hope ” to stimulate more research, both qualitative and quantitative, in an area that we believewill reward further exploration – not only in the United Kingdom but also in other countries with rich energy history” (p. 2).

3.3. France

In France, volume 2 of the Annuaire statistique de l’économie française aux 19ème et 20ème siècles contains numerous long series on the energy industries (production, costs and prices, capital and personnel), but very little data on total primary consumption[17]. This gap has since been filled by a study commissioned by the Observatoire de l’Énergie, which seeks to place the decline in the energy intensity of economic activity observed between 1973 and 1986 in a long-term perspective: was it simply a temporary reaction to the sharp rise in oil prices, or a change in the long-term trend? In order to make a decision, the authors Jean Rouchet and Pierre Vila undertook an ambitious reconstitution of long statistical series and questioned the models likely to explain the variations in energy intensity[18]. We thus owe them a very complete series covering more than two centuries (1787-1996), from which it emerges that primary consumption increased from 6.84 to 235.67 Mtoe, i.e., an average annual growth of 1.7% over the period, and that per capita consumption rose from 0.25 toe at the beginning of the 19th century to 0.5 in 1870, then to 1.5 in 1929 and 3 in 1970.

3.4. Other countries

The long series reconstructed for Italy by Carlo Bardini are also exhaustive, but unfortunately limited to a much shorter period (1863-1913)[19]. From a perspective that is both descriptive (periodizing growth rates and comparing them between European countries) and explanatory (identifying technological changes attributable to the need to use new energy sources), the author establishes that primary consumption rose from 3.8 to 13.6 Mtoe, a strong growth of 2.6 percent, corresponding to the period of Italy’s industrial expansion. During the half-century studied, the share of wood fell from 82% to 29%, while that of coal jumped from 10% to 58%, and hydroelectric power gradually replaced direct hydraulic power (water mills). The inclusion of the latter at 10% of total primary consumption in 1863 explains the discrepancy with our own estimates at that date.

In Japan, Yasushi Ninomiya gathered the long series of data available in his country for the period 1887-1998 in order to establish the relationship between energy consumption, economic activity (GDP) and energy prices[20]. He concludes that, over a century, the elasticity of GDP is about 1 and the elasticity of price is -0.15, which indicates that prices have little influence on energy consumption. The data on which it is based indicate a per capita primary consumption of 2.4 Gcal in 1900 and 44.3 in 1998, i.e. a multiplication by 18. During the same period, the share of traditional sources fell from 51.6% to 0%, while that of hydrocarbons rose from 3.5% to 65.2%.

Finally, for Brazil, the reconstitution of a long series over the period 1900-1962 concluded that primary consumption, including wood, increased from 6.6 to 31.2 Mtoe, or 2.5% per year on average[21].

4. Estimation of non-commercial consumption

All in all, the combination of long time series from statistical yearbooks and national studies provides, at least for the major industrialized countries of long standing, fairly consistent trends in consumption from commercial sources. The same cannot be said of non-commercial sources, whose estimates must be re-examined by comparing the various sources of information identified (see: World Energy Consumption Before the Industrial Era).

4.1. United States

For this country, we have the series established by S. Schurr (p. 491 and following), from 5 years to 5 years, between 1850 and 1955 in thousands of cords and in trillion (¹⁰¹²) Btu, based on the work of R.V. Reynolds and A.H. Pierson[22] and then on the Service Forest Reports: in Mtoe, the consumption of the United States would have evolved from 53.5 in 1850 to 26.7 in 1955, passing through a maximum of 72.3 in 1870. In relation to total energy consumption, the share of wood would thus have fallen from 90.7% in 1850 to 21% in 1900, then 3.3% in 1950 and 2.6% in 1955. Per capita consumption (p. 521) would have fallen from 2.3 toe in 1850 to 0.7 in 1900, 0.19 in 1950 and 0.16 in 1955.

What is the value of these data? According to the authors (p. 46), these are orders of magnitude rather than precise quantities, since statistics were totally lacking and, quoting Reynolds and Pierson, they add ” Cordwoodwas about as plentiful as air. But nobody wrote about air – why write about firewood, or even record statistic about it? The mentioned consumptions are therefore estimates based on the knowledge of the heating needs, taking into account the climate, the habitat and the availability of wood. Their evolution is guided by what we know about the substitution of fireplaces by stoves and of wood by coal[23]. Some data on the consumption of biomass by households in the 20th century are more precise. The 55 million cords in 1950 were estimated by the Stanford Research Institute as follows: heating of farms (20.6); heating of rural dwellings other than farms (13.0); district heating (5.8); open fireplaces (14.0); other (1.6).

Schurr’s statistical series is worthy of comparison with Palmer Putnam’s (1951, pp. 370-421) series from 1800 to 1949. According to this author, wood consumption in^{1012 Btu} would have increased from 594 in 1800 to 2800 in 1850, 2900 in 1900 and 1745 in 1949, that is, in Mtoe 148.5; 70; 72.5; 43.6 respectively. Compared to the total consumption of energy, the biomass would have represented during the same years: 99,31%; 92,48%; 28,33% and 4,56%. That is to say an annual consumption per capita of 2.8 toe; 3.0; 0.7 and 0.3. He also specifies (p. 370) that he has omitted animal energy sources, estimated at 1.4% of total primary consumption in 1850 and 0.29% in 1940, but that he has introduced fuelwood, also based on Reynolds and Pierson and then on data from the forestry services (p. 381), by multiplying the population of 12 regions by the unit consumption of their inhabitants. The latter take into account climate, wood species, population characteristics, housing conditions, heating patterns, and the diffusion of fossil sources. Excluded are the volumes of wood transformed into charcoal or distilled (perhaps 0.8% of consumption between 1800 and 1930) and part of those burned by woodworking industries (sawmills and woodworking shops) because they could not be broken down between regions.

Since the Schurr and Putnam population series are identical, comparison of their fuelwood consumption is possible (Table 3).

Table 3: Schurr-Putnam comparison of biomass consumption in the United States.

Putnam’s estimate is always higher than Schurr’s, perhaps, he himself mentions in connection with a comparison with another author, because he included a portion of plant waste that is rarely taken into account. Moreover, his very slight increase in wood consumption between 1850 and 1900 contradicts Schurr’s decrease. Over the whole period, however, the per capita consumption and percentages of the two authors are consistent and constitute a good assessment for the North American continent.

4.2 France

In this regard, we still have two evaluations, including one by Putnam (pp. 330-339), who specifies that his data are those of the FAO doubled to those of the Fourth World Energy Conference, which includes, unlike the FAO, rural and non-commercial consumption of fuelwood. The series, in 10¹²,Btu covers the period 1850-1946, that is, after conversion into Mtoe, a total consumption estimated at 1.9 in 1850; 2.1 in 1900 and 4.8 in 1946, which corresponds to a constant per capita consumption over the whole period of 0.05 toe. It is not surprising, on such a basis, to find that the percentage of biomass in France fell from 35% in 1850 to 5.6% in 1900 and then rose again to 9.3% in 1946.

The work of Alain Corroyer (1980)[24] and Jean Rouchet and Pierre Villa (1998)[25], which mobilized the work of historians such as F. Braudel (1967), T.J. Marcovitch (1965, 1966) and J.C. Toutain (1961, 1963) are therefore particularly valuable for correcting Putnam’s estimates. The first, on the basis of equivalences very close to those used above[26], uses (p. 143) Marcovitch’s estimates of fuelwood consumption, i.e., converted from Mtoe to Mtoe: 8.1 in 1830; 8.5 in 1835-44; 7.8 in 1845-54; 4.9 in 1935-38; 4.2 in 1942 and 3.5 in 1946. To which we might add for 1789-1800 the 7.8 calculated by Turin (1978), higher than Braudel’s extrapolation (6.5) but lower than Marcovitch’s estimate (10.6). In 1796, 42 percent of this consumption was for heating cities and the countryside, and 58 percent for forges and blast furnaces (p. 145); 60 percent was for domestic use and small-scale industry, 1 percent for transport, and 39 percent for industry and mining between 1845 and 1954 (p. 146).

The annual series in Mtoe, from 1787 to 1996, reconstructed by Jean Rouchet (pp. 32-33 of Part III Results) traces the evolution of wood consumption from 6.60 in 1800, to 5.40 in 1850, to 2.60 in 1900, to 0.80 in 1950, and to 4.20 in 1996, following an upward trend that began in 1974. What is included in these data (pp. 28-34 of Part II Sources and Methods)? Firewood as recorded in the forestry statistics and, from 1970 onwards, other renewable sources (recovery of household and industrial waste, geothermal energy, active solar energy). However, the series excludes volumes consumed by households, which, according to a 1992 survey, amounted to 35.8 Mt or 9.2 Mtoe. This difference of 5 Mtoe (9.2-4.2) reflects an underestimation that does not only affect the end of the period, since the 0.8 of 1950 reflects poorly what is known about consumption in the immediate post-war period. Overall, a comparison of these data suggests that the highest (Corroyer) should be preferred, with 13.4 (4.2+9.2) for 1996, and that the change in per capita consumption should be calculated on this basis (Table 4).

Table 4: Putnam-Corroyer-Rouchet comparison of biomass consumption

4.3. Italy

For Italy, we have the work of Carlo Bardini (1991), which includes a Combustibili legnosi series with annual data for 1863-1913, constructed by summing the production of legna da ardere dei boschi + legna da ardere non boschiva + legna da carbonizzare and imports of legna da ardere, legna da carbonizzare and carbon di legna. All the data have been converted into kcal, but on the basis of 1,350,000 kcal/m3, which is very different from the one used above (2,500,000) because of the volume/weight equivalence (450 kg/m3 instead of 725/m3). Subject to this reservation and those that may be inspired by the calculation methods, the annual consumption of biomass in Mtoe is as follows: 3.2 in 1863; 3.4 in 1900 and 3.5 in 1913, i.e., in toe per capita on the same dates: 0.13; 0.11 and 0.10. As a percentage of primary energy consumption, biomass would thus have fallen from 81% in 1863 to 43% in 1900 and 28% in 1913.

4.4. Other countries

Brazil, a large consumer of biomass, deserves to be examined: over the period 1900-1962, by adding the consumption of fuelwood, bagasse and charcoal deducted from fuelwood, we arrive at total consumption of 6Mtoe in 1900; 12.9 in 1950 and 14.1 in 1962, i.e., in relation to the population: 0.33 toe in 1900; 0.25 in 1950 and 0.18 in 1962. And as a percentage of total energy consumption: 90.9; 66.5; 45.0[27].

For the other countries of the world, the only estimates found are those of P. Putnam, which range from 2.7 to 4.0 Mtoe for Argentina; 2.6 to 4.4 for Germany; 54.0 to 78.9 for India; 10.5 to 20.0 for Japan; 27.5 to 87.0 for the USSR; and 284.2 to 489.0 for the world as a whole, passing through 359.5 in 1900. Relative to population (toe/capita) and total energy consumption (%), these estimates can be summarized as follows (Table 5).

Table 5: Biomass consumption in various countries according to Putnam

How did P. Putnam arrived at these figures? For world wood consumption (p. 443), he relied on the study of foresters[28], which he extrapolated using, among other things, the evolution observed in the United States. The recent FAO data, he notes, must always be at least doubled if one wants to take into account the consumption of non-commercial wood, which the International Organization excludes, as well as that of animal and vegetable waste, also obtained by extrapolation. These results must therefore be taken with caution, but some of Palmer Putnam’s national observations deserve attention.

In Argentina (1922), wood is used for home heating (open fireplaces, stoves, central heating) and to a lesser extent for railroads and industry, with an efficiency estimated at 25%, halfway between the fireplace and the stove in the USA. Vegetable waste which, at the same date, represents 20% of primary consumption, includes “bagasse of sugar cane, quebracho sawdust in the tanningextractindustry, grape refuse fromwine presses, corncobs, wheatstraw, riceshells, oilyseeds, bran and bran refuse. The war crisis added maize, wheat, linseed, linseed oil and flax as substitute fuels” (p. 329).

The consumption of animal waste in India is based on the estimates of specialists (H.C. Schor and P.E. Howe) who calculate the calorific content of cow dung as a function of the weight and fodder absorbed by the cows (pp. 353-54). Considering that the heating of Indian houses is almost entirely provided by this fuel, Putnam attributes to it an average efficiency of 5%.

Found in the work of E.B. Schumpeter[29], the direct consumption of fuelwood in Japan in 1915 and 1937 is multiplied by 1.20 to take into account charcoal, estimated at a little more than 10% of the fuelwood, and brushwood, which must also be added. The combustion efficiency of the various forms of wood ” primarily in braziers mounted indoors” is estimated at 15%.

The main source of information on the Soviet Union is the study by A.E. Probst[30] who estimates the consumption of firewood in domestic heating at 1.82^m3 per year in cities and 1.63 in the countryside, a weighted average of 1.7, constant over time. Judging these data to be underestimates, because they ignore the wood cut by rural populations, Putnam raises biomass consumption from 28.5 to 39.66% of the 77.15 Mtoe that measured total consumption in 1935 (p. 433). Regarding the long-term evolution of efficiency, Putnam first notes that ” In an agrarian state in the temperate zone, domestic heating is the dominant constituent of the energy system” (p. 434) and that one of the characteristic features of Russia was the early use of stoves. ” The usual russian domestic stove is a ponderous structure extending from the floor to the ceiling and is one yard wide and to 0.5 yard deep; the outer surface is corrugated and covered with glazed tiles for better transfer of heat. The stove is usually located in the center of the house, intersecting the partitions, with the stove corners projecting into the various rooms. Such an arrangement provides for a fairly high domestic-heating efficiency, certainly much higher than that of western-style fireplaces. Putnam therefore believes that the efficiency of this type of heating, already very high in 1850 (35%), continued to grow to 38% in 1917 and 41% in 1940, thanks to technical progress (Read: Energy in Russia before 1917).

4.5. Other estimates of biomass consumption

For the countries of Western Europe, Paul Bairoch estimated that per capita biomass consumption had been significantly higher than those retained by Palmer Putnam (Table 6).

Table 6: Biomass consumption in Western Europe according to Paul Bairoch.

Letter from Paul Bairoch to the author in April 1987. His estimates in kec have been converted to kep.

He specified, however, that the differences between countries should not be exaggerated, since there was a certain compensation between climatic and technical effects: the coldest countries generally had more efficient heating appliances and better insulation of their dwellings[31].

On the same subject, Angus Maddison gives total biomass consumption in 1913 of 4.3 Mtoe in Japan; 7.4 in France; 8.5 in Germany and 6.1 in the United Kingdom[32], while the Woytinsky[33] (Figure 4) retain the following estimates for 1948 (Table 7).

Table 7: Consumption from traditional sources in the world in 1948

The data in Mtec have been converted to Mtoe.

Fig. 4: Wladimir S. Woytinsky (1885-1960) and Emma Shadkhan Woytinsky (1893-1968) [Source: archivesofthecentury.org]

At this date, animal power and biomass thus represent, according to the authors, 17.3% of total world consumption (14% for biomass alone). This quantity would have varied little over time, from 280 Mtoe/year in the middle of the 19th century to 350 since, its decline in Europe having been much less spectacular than in the United States. In relation to the population of 1950, this consumption amounts to : 119 kep worldwide; 235 in the United States and Latin America; 163 in Europe excluding the USSR; 259 in the USSR; 55 in Asia and 105 in Africa. They are not far from the other estimates for North America and Europe, but much lower for the USSR and especially Asia.

5. The evolution of the world population

In the absence of long statistical series on biomass consumption, there is no other solution than to reconstitute them by multiplying, year by year, the population of the countries and/or regions of the world by the estimate of per capita consumption considered the most relevant among all those gathered above.

Data on population change are less scarce than data on energy consumption. Most of the advanced capitalist countries, and sometimes a few others, have had periodic censuses since the early, mid, or late 19th century. Their results are available in various statistical yearbooks, including those of B.R. Mitchell. Since 1950, the United Nations and then the World Bank have published annual data on the population of all countries in the world. Angus Maddison processed both historical and recent data, in particular in order to homogenize national spaces whose political borders have sometimes varied considerably over time[34]. His evaluations, published in the third referenced work, provide demographic developments:

• for 1820, 1850, 1870, 1890, 1900 and then year by year for the less developed countries and year by year from 1870 for the others;
• this was done for a sample of 56 countries, the results of which were extrapolated to 199 countries grouped into 7 world regions.

Within the framework of the regional division adopted, the chronicles of the countries and regions of A. Maddison were completed and, if necessary, corrected with the help of the following sources: from 1970 onwards, by the annual series of the World Bank; between 1800 and 1870, by searching for missing data in the historical directories already mentioned or in the works of historical demography by Marcel Reihnard[35], Jean-Noël Biraben[36] or others. The consistency of these demographic data has run into a number of difficulties.

The greatest difficulties relate to the ten African countries selected (Egypt, Ethiopia, Ghana, Côte d’Ivoire, Kenya, Morocco, Nigeria, South Africa, Tanzania and Zaire), and therefore also to the African region. Historical demographics are of very limited help. ” Until the 19th century,” write Marcel Reinhard and his colleagues (p. 280), “African populations cannot be estimated; data are lacking. We were left with the very random approximations of Gregory King who proposed 95 million souls“. For the following period, they provide some scattered data, notably for South Africa and the Maghreb countries.

For Latin America and Asia, the gaps are less serious, since estimates are available for most countries at the beginning of the 19th century and complete annual series from 1900 onwards. However, the data do not always coincide. For example, for China, which appears to be defined within the same boundaries (without Formosa/Taiwan), Maddison’s and Reinhard’s populations coincide in 1950, but not for certain years of the 19th century (Reinhard’s 260 million in 1812 is low compared to Maddison’s 381 million in 1820). The latter are consistent with those of P. Putnam (p. 267), who repeats Usher’s interpretation of the censuses of 1780 (276.6 million), 1812 (360.4), 1842 (413.0), 1860 (260.0), 1885 (377.6), and 1923 (414.0), who does not fail to express his astonishment at the magnitude of the 1860 collapse. They are also the same with those of J.N. Biraben: 330 in 1800, 435 in 1850, 415 in 1900 and 558 in 1950, although here again the fall between 1900 and 1923 must be explained.

In the case of Oceania, the main problem is related to the evolution of local populations. Even if poorly known before 1850, the populations of Australia and New Zealand give a tiny total compared to the population estimated by Reinhard (p. 680), i.e. 2 million in 1800 and 1850, which seems excessive compared to the sum of the populations of the Pacific Islands mentioned by Mitchell[37]. This leaves the Aborigines of Australia, whose numbers are known to have decreased, but perhaps not to such an extent.

Other problems relate to the variations in the borders of a number of countries. With the exception of East Germany, which became part of Eastern Europe between 1945 and 1990, these problems do not affect the demographic development of regions. They do, however, have an impact on the demographic development of various countries. A. Maddison reasons in “constant territory” in order, he says, “to get a clearer picture of the underlying trends in economic growth” (p. 247). To do this, he applies a correction coefficient to all the previous data for a country, calculated from the difference in population in the year of the border change. When several changes have occurred over the past two centuries, as is the case for all European countries whose borders were modified at the end of each world war or when the Iron Curtain collapsed, the last change is used. All the national demographic series used here are thus formatted on the basis of the 1992 borders, resulting in very different series from those with variable borders for countries such as Austria, Germany or Russia/USSR.

In order to check the risks of distortion due to data differences, several sources were compared, over a few years, for the world and 7 major regions, Eastern and Western Europe being combined. For the world, the Enerdata Long Series data deviate from Reinhard’s (1 to 2%) and Biraben’s (2 to 7%) between 1800 and 1900, almost exclusively because of differences in the evaluation of the African population. If Biraben’s 102 million (1800, 1850) seems really excessive, Reinhard’s 90 and 95 may be less so, although these estimates seem high to us. The 70, 75, and 95 (1900) that we have retained will therefore have to be carefully re-examined.

For the other regions of the world, the divergences that appear between authors are rarely significant. They do not exist for any of the Americas from one end of the period to the other. For Oceania, a better estimate of indigenous populations is needed, especially in 1800 but also in 1900 (-17%) and 1950 (-23%). For Europe, the population retained in 1800 is intermediate between Reinhard’s and Biraben’s estimates; it deviates slightly from both in 1850 and 1900 before joining them from 1950. The main difficulties arise from the data for Russia and other countries that would later join the Soviet Union (Table 8).

Table 8: Evolution of the world population by region 1800-2000.