Late Victorian Holocausts: El Niño Famines and the Making of the Third World

El Niño Southern Oscillation (ENSO) has a history. Scientists sought for generations to explain the weather phenomena they noted in conjunction with the droughts that impacted India, China, Brazil, parts of Africa, and southeast Asia.

Solar energy along the Equator influences global climate. However, tropical areas “do not accumulate heat evenly” (226). Ocean currents and winds store this solar energy in multiple spots along the Equator. In the Pacific, trade winds from the east move warm surface water westward. A “Warm Pool” therefore appears in conjunction with an atmospheric “heat engine” called the Indo-Australian Convergence Zone (IACZ). This formation moves energy into the atmosphere from the ocean waters in the form of condensation. It is, essentially, a “cloud factory” in the Western Pacific Ocean (226).

ENSO happens when the trade winds reverse or stop, allowing the cloud factory to move east. The “Southern Oscillation” appears as barometric pressure in eastern and central Pacific region falls while it rises in the opposite direction. The Pacific Ocean warms off the Ecuadorian and Peruvian coasts, as does the Indian Ocean. When ENSO is strong, the monsoons in India and southern Africa fail, and rainfall decreases in northern China and Brazil’s Nordeste. Meanwhile, flooding occurs in the deserts of Peru. ENSO thus causes rainfall patterns to shift due to these changes (or “oscillations”) in barometric pressure and ocean temperature.

European colonial and imperial expansion led to the discovery of this global phenomenon. ENSO spawned a drought in south Asia from 1790-91, impacting British colonial holdings in the Caribbean: “For the first time, simultaneous meteorological measurements thousands of miles apart hinted that extreme weather might be linked across the tropics […]” (228). William Roxburgh, a naturalist and physician with the East India Company, investigated links “between climate, food supply and famine in Madras,” blaming the company’s deforestation for the crisis. By 1876, the empire considered meteorological study of the tropics an important part of its imperial business and had put in place “the operational rudiments of a world climate observation system” linked by new technology, including the telegraph. International weather record-keeping was standardized. Henry Blanford, “imperial meteorological reporter to the government of India” collected and assessed international data (229). Blanford concluded that oscillating barometric pressure along the axis linking Russia to India caused periods of weakened rainfall. Though Blanford’s work laid the foundation for future discoveries, his location of this axis was incorrect, and the British Raj maintained that climate was the lone cause of the late Victorian droughts. The British believed that if scientists could identify the “global mechanism” that caused the oscillation and resulting droughts, they could predict future outcomes. Such knowledge would “be of immense advantage to tropical imperialism” (231).

Early investigators argued that sunspots influenced the monsoon cycles, while other scientists expressed doubt about this theory. Richard Stratchey, for instance, suggested that these were chance correlations. Nevertheless, the sunspot theory gained traction. Scientists also postulated a link between the eastern and western droughts, with some using the sunspot theory to explain desiccation in Brazil while others attributed famines in the Global South to Social Darwinism. They suggested that deforestation and the agricultural techniques practiced by racially inferior farmers in the sertáo caused drought.

The British economic theorist Sir Stanley Jevons embraced the sunspot theory, arguing that the sun’s power over the eastern monsoons (and thus farming) “drove the entire global business cycle” (234). Political and economic motives thus buttressed the sunspot theory because it suggested, per Jevons, that capitalism’s weaknesses were not responsible for global economic crises—nature was. However, this theory started to fall apart in the 1890s: “For every study that associated drought with sunspot maxima, there seemed to be another that correlated it with sunspot minima” (235). Meanwhile the British astronomer Norman Lockyer argued that oscillation was the result of two phases: one Spanish and one Indian. This theory of “inter-hemispheric atmospheric oscillations, with possibly more than one frequency, provided a compelling framework for the next generation of research” (239).

By 1924, Sir Gilbert Walker had identified three linked oscillations, including the Southern Oscillation. Yet Walker was unable to determine “an index or system of equations that would give even proximately reliable advance warnings of drought” (241). Scientists did not yet know that temperature changes in the Pacific intersected with atmospheric pressure shifts. Jacob Bjerknes at UCLA took up research into this mystery in 1969, employing both meteorological and oceanographic methods. He asserted that the Southern Oscillation resulted from “exchange of energy between the ocean and the atmosphere” (243). The sunspot theory finally died. Klaus Wyrtki at the University of Hawaii built on Bjerknes work during the 1970s. He determined that a “trigger event” like a trade wind causes heat from the “Warm Pool” to release in a stream that moves eastward across the Pacific (245). Further research concluded that ENSO is influenced by external weather phenomena. Moreover, ENSO is followed by “La Niña,” which has an opposite, cooling effect “so that droughts are often followed by severe floods as in China in 1897-98 or 1997-98” (246).

Questions remain today about historical ENSO cycles and modern climate change’s impact on El Niño: “A popular hypothesis is that much of the additional heat trapped by greenhouse gases is stored in an expanded Warm Pool […]” (251). This hypothesis holds that discharged warm ocean currents flow eastward in “more frequent and larger El Niño events” (251).