Under the Brown Cloud

Anantapur District, southern India.

You probably haven’t noticed, but days aren’t as bright as they used to be. Sunlight intensity, averaged across hundreds of locations on all continents, decreased by 1.5 to 3% per decade from the 1950s to 1990s. The dulling of the sky can be traced largely to the burning of fuels, which releases soot, sulfates, nitrates, and other substances that absorb and reflect a portion of the sunlight that normally would reach the Earth’s surface.

When reported a few years ago [1], these findings were controversial, but subsequent research has helped confirm the reality of “global dimming.” However, to paraphrase the old saying about politics, all global climate change is local. Over the past decade, clean-air laws and export of dirty industries have halted dimming and even led to some brightening (and warming) in the U.S. and Europe. Meanwhile, as we shall see, continued dimming over Asia could well mean more erratic monsoon rains and less food for 2 billion people.

If that indeed happens, the chronically drought-stricken district of Anantapur here at the southern end of the Indian state of Andhra Pradesh may provide a grim preview of South Asia’s future. Lying between Hyderabad and Bangalore — the country’s two great traffic-choked foreign-investment capitals and major sources of the brown haze that blankets the subcontinent every year from November to April — this impoverished rural region never sees a very good monsoon. The area lies in a “rain shadow” from India’s southeastern mountains, and as a result, its average annual rainfall is only about 20 inches, often concentrated in a few downpours between June and September. And even that meager monsoon is increasingly undependable: Of the nine years since 1930 that saw rainfall below 16 inches, six have occurred since 1980 and two since 2002.

A recent study by India’s National Climate Center showed that over the past century, 12 of 36 regions in India, including the region that includes Anantapur, have seen decreasing annual rainfall. But despite living in the driest part of southern India, the 3.6 million people of Anantapur district — 2.7 million of them in small villages — continue to rely on agriculture as the foundation of their economy, indeed their existence. Now, immense, drifting brown clouds produced by the booming, mostly urban, demand for electric appliances, automobiles, and other fossil-fuel-guzzling features of twenty-first-century Indian life could undermine Anantapur’s survival in way that centuries of persistent “natural” droughts have not.

Playing with the dimmer switch

The deepest dimming during the past half-century occurred in the Northern Hemisphere, most intensely in the most heavily populated regions [2], and especially in the United States, with its voracious energy consumption. Anti-pollution efforts in the industrialized West, along with the 1990s economic crash in the former Soviet Union and Eastern Europe and the large-scale relocation of manufacturing to Asia, curbed the release of pollutants in the West, and that appears to have led to overall global brightening in the last decade or so. Some analysts now say the sudden onslaught of hot years over much of the world since since 1990 actually represents a longer, more gradual warming trend that was masked back in the 60s, 70s, and 80s by a shady layer of soot and sulfates.

But dimming continues across large parts of the globe, and history shows that the result can be severe drought and plummeting crop production. Recent research has shown that decades ago, sulfates from industrial Europe and North America weakened atmospheric circulation in the intertropical convergence zone, causing rains to fail in Africa’s Sahel region, south of the Sahara desert [3]. The resulting Sahelian drought of the 1970s and 80s ended up killing more than a million people.

Now, food production in South Asia is imperiled by phenomena known as “atmospheric brown clouds.” Rapidly industrializing areas of Asia and the surrounding oceans have seen continued darkening, associated with the emergence of extensive, murky clouds with lifetimes measured in weeks. Fed increasingly by combustion of coal, diesel, and gasoline, brown clouds have been returning, darker and larger each winter, over South Asia and the northern Indian Ocean [3].

The brown clouds have cut the amount of sunlight reaching the land and ocean surfaces by approximately 8% between 1930 and 2000 [4]. While shading and thereby cooling the surface, the brown clouds absorb heat and warm the atmospheric layer in which they hover. That has several nasty consequences: reduced evaporation from the ocean surface (which means less moisture available for rain); warmer-than-normal clouds that contain more fine particles of pollution and can hold more moisture without releasing it as rain; and perhaps most ominously, a potential weakening of the climatic engine that drives the monsoon rains [4,5]. That could mean lower crop yields across much of India, Pakistan, and Bangladesh, and it could tip already drought-afflicted areas like Anantapur District into ecological and humanitarian crisis.
Living with drought

Traditionally, Anantapur’s farmers have dealt with their bad draw in the climatic lottery by growing tough subsistence crops: pearl millet, finger millet, deep-rooted legumes like pigeonpea, and, on better soils, chickpea. Over the past two decades, cash-crop peanut mania swept the district, eventually covering its arable land in a near-monoculture. But drought, soil exhaustion, and a plant virus have driven peanut yields down and reduced the typical seed’s oil content from almost 50% down to 36%. Because the crop is grown mainly for cooking oil production, farmers are getting lower prices for smaller crops.

Fully 80% of the district’s rural people are small farmers, not fat-cat landlords or landless laborers, but that relatively well-balanced farm economy is getting harder to maintain. Economic pressures, coming on top of increasingly erratic rainfall and depletion of groundwater supplies, have helped push Anantapur toward the top of the list of districts for numbers of farmer suicides, which are reported to number in the thousands. The water table has dropped as much as 15 feet in some places, and more wells are being drilled ever-more deeply to get at ever-less water. It’s also reported that 10 to 15% of farmers have fled the crisis to look for work in urban areas.

I recently visited farmlands around the village of Velikonda, one of 54 watersheds in the district where farmers, assisted by the nonprofit group Acción Fraterna, are using water-harvesting methods, a more diverse array of crops, and natural pest control in an effort to sustain their communities and food supplies over the long haul. There, and in other villages in the district, it’s clear that communities accustomed to surviving hard times are not going to give up without a fight.

With the help of engineers, hydrologists, agronomists, and local laborers, and organizing themselves into teams of 15 farm families (of various low castes and non-castes, but none of them well-to-do), people in Velikonda and a host of other villages are planning and building large water-conservation networks. Using mostly hand labor, they have built thick, chest-high earthen berms around the downhill edges of fields to trap precious rainwater that would otherwise run off into gullies during storms. More than 100,000 acres in the district are now protected by such berms.

In the same way, they are hand-digging ponds of 40,000-gallon capacity that can hold rainwater to be hand-carried to new orchards of mango or custard-apple trees. Farmers pay a percentage of the cost of berms, drainage outlets, and ponds on a sliding scale (with the rest coming from Acción Fraterna, which is a part of India’s Rural Development Trust. Indian government programs are now also helping fund such projects.)

They also are moving away from a food economy based on selling peanuts and buying nutrient-poor, government-subsidized rice. In an effort led largely by women, they are re-diversifying their cropping system with nutritious crops they can both consume and sell: millets, sorghum, pigeonpea, broad beans, cluster beans, chilis, coriander, and many more. They have stopped buying costly pesticides, turning instead to natural products like neem seed extract. They are growing non-crop plants like milkweed to trap insects instead of trapping themselves in debt to buy chemicals. They are growing large leguminous plant species on the water-holding berms, to be cut and spread back on the land to add organic matter and nutrients.

Where these self-organized community efforts have taken root, individual despair under the brutal logic of the national and international economy has withered. The work is on a colossal scale and no doubt exhausting, but the atmosphere in the villages is electric. Velikonda and the other places where I saw such cooperative work happening are not the places that continue to be plagued by farmer suicides.
Darkness on the horizon

But even if the people of Velikonda and thousands other villages make every right move within their local, water-limited means, the global economy may not be finished with Anantapur. India’s rapid industrialization has added 50% on top of the pollutant emissions that have come with population growth since 1930 [4]. That foul output has accelerated with the opening of the nation’s economy over the past decade and a half. India’s integration into the world market has meant cheaper merchandise and services for Western consumers and greater wealth for an upper slice of India’s urban minority. But India’s captains of industry are achieving prosperity the same way the powerhouse economies of the West were built: with products and technologies that burn every kilogram of fossil fuel that comes within reach.

If the boom continues to darken and thicken the atmospheric brown clouds that, in turn, are threatening to disrupt the monsoon, it could destroy everything that the resolute farm communities of Anantapur have managed to accomplish. Moreover, it could undercut the livelihood and food supply of the rural majority all across the country.

Computer models predict that nationwide monsoon droughts, which historically occur an average of two to three years per decade, could rise to as many as six years per decade under the influence of brown clouds [4]. If Anantapur is affected as badly as the nation as a whole (and the models appear very uncertain about local variations), agriculture might just become impossible. People there say they already count on drought at least six years in ten; brown clouds conceivably could make that a perfect ten out of ten.

Foreign investment and production for export in India have not come close to the levels they have reached in China, but they have played an indispensable role in creating the country’s urban economic explosion (and they have dwarfed by orders of magnitude the foreign funds that have come in to support rural nonprofits like Acción Fraterna). Such upheavals never come without surprises. And no sudden, human-made climatic change in a random direction has, as one might expect, an equal chance of being either harmful of beneficial. Because life on Earth evolves toward equilibrium with its current environment – and on a long time scale – and because industrial civilization has become so complicated, fragile, and vulnerable, any rapid climatic change, including dimming, is almost guaranteed to prove a disaster with no silver lining.

No one knows, for example, how the complex tug-of-war between global warming and local dimming will turn out. But the results for South Asia are unlikely to be pleasant. The leader of the Atmospheric Brown Clouds Project, Dr. V. Ramanathan of the Scripps Institution of Oceanography, has said, “Some years the aerosols [i.e., the pollutants causing dimming] might win and in some years the greenhouse effect may win. So we are concerned that in coming decades the variability between the two will become large and it will be difficult to cope with rapid changes from year to year.” [6]

The straightforward approach to both warming and dimming is, of course, to make deep cuts in energy consumption planet-wide. The rapidly industrializing nations of the South will have to find their own ways to get the energy they need without ecological devastation. But with the average American using 10 times as much energy as the average person in China, and 24 times as much as the average Indian, it’s the clear duty of the United States to take the lead in slashing consumption.

Instead of that, scientists and policymakers are focusing on technological fixes like carbon sequestration, stratospheric sulfur seeding [7], and colossal, space-based mirrors [8]. Growth-dependent economies were built around the fossil-fuel power bonanza and have no way to handle the consequences of the deep energy cuts that are necessary. Global capitalism will not – indeed, cannot – give up the easy exploitation of concentrated energy that need only be mined or pumped. And with its global reach, it will probably entrap even communities like Velikonda that seem determined to wriggle free. Overall, it makes for some pretty dim prospects.

STAN COX is a plant breeder and writer in Salina, Kansas. Write him at t.stan@cox.net.

You can visit Acción Fraterna’s website at http://www.accionfraterna.org/home.html


1. Stanhill, G. and S. Cohen. 2001. Global dimming: a review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agricultural and Forest Meteorology 107:255-278.

2. Alpert, P., P. Kishcha, Y.J. Kaufman, and R. Schwartzbard. Global dimming or local dimming?: Effects of urbanization on sunlight availability. Geophysical Research Letters 32: [web reference] L17802, DOI:10.1029/2005GL023320.

3. Rotstayn, L.D. and U. Lohmann. 2002. Tropical rainfall trends and the indirect aerosol effect. Journal of Climate 15:2103-2116.

4. Ramanathan, V., C. Chung, D. Kim, T. Bettge, L. Buja, J.T. Kiehl, W.M. Washington, Q. Fu, D.R. Sikka, and M. Wild. 2005. Atmospheric brown clouds: Impacts on South Asian climate and hydrologic cycle. Proceedings of the National Academy of Sciences 102:5326

5. United Nations Environment Program, “The atmospheric brown cloud: climate and other environmental impacts” (http://www.rrcap.unep.org/issues/air/impactstudy/index.cfm)

6. Scripps Institution of Oceanography press release (http://scrippsnews.ucsd.edu/article_detail.cfm?article_num=731)

7. Crutzen, P. 2006. Albedo enhancement by stratospheric sulfur injections: A contribution to resolve a policy dilemma? Climatic Change: [web reference] DOI 10.1007/s10584-006-9101-y

8. Govindasamy, B., and K. Caldeira. 2000. Geoengineering Earth’s radiation balance to mitigate CO2 -induced climate change. Geophysical Research Letters 27:2141.


Stan Cox is the author of The Green New Deal and Beyond: Ending the Climate Emergency While We Still Can (City Lights, May, 2020) and one of the editors of Green Social Thought.