Chapter 1

More than no rain

The word “drought” conjures up images of cracked earth, dust storms and emaciated cattle. But that is only one face of drought. Drought is not only the absence of rain. It is a cluster of disasters unfolding in slow motion. Drought goes deeper than the topsoil and lasts longer than the next rainstorm. This is why, once drought takes hold, it takes considerable effort by people—and nature—to recover fully.

Background: Trees covered in spider webs during flooding in Sindh, Pakistan. Photo Credit: UK Department for International Development (Used under Creative Commons license).

The complexity of drought

Most of us in the United States would define drought as a period of unusually dry weather. That’s because, for many of us, that’s all that drought is. We might pay a little more for some groceries. If things get really bad, we might be faced with restrictions on how much we can water our lawns or when we can wash our cars.

Because so few of us work in agriculture, most Americans don’t appreciate the subtle cues in the natural world that tell us something isn’t quite right. We don’t notice if crops aren’t growing as high as they should. We don’t notice when storms don’t come or when reservoirs aren’t as full as they should be. We don’t notice when topsoil slowly dries out. The great majority of us don’t grow food or live in close proximity to where our food is grown, so we don’t notice when droughts start to take hold.

We don’t know there’s a drought until someone tells us, and by then it’s usually reached crisis level. Once the rain returns, most of us assume things are back to normal.

But drought is far more complex than that. A lack of precipitation does more than dry out fields and reduce the amount of water available for human consumption. Even when droughts seem not to last very long, they have consequences that resonate for a very long time.

Drought is a series of events

It is more accurate to think of drought as a series of events triggered by an initial lack of precipitation.

1. No precipitation. Drought can come slowly or quickly, but it always begins the same way: snows don’t come in winter and rains don’t come in spring.

California State Capitol, Sacramento

California state capitol, Sacramento, displaying a sign promoting water conservation over lawn care, July 2014. Photo Credit: Kevin Cortopassi (Used under Creative Commons license).

2. Pests. Drought dries up crops and kills farm animals, but that’s often only the most obvious effect drought has on plants and animals. More fundamentally, drought throws nature’s natural checks-and-balances system out of whack, creating the conditions in which pest populations explode. Also, just as drought displaces people, it displaces animals, too, and swarms of insects and rodents sometimes move out of drought areas and cause disasters elsewhere.

Potato psyllid nymphs

Potato psyllid nymphs. Photo Credit: Center for Invasive Species Research (Used under Creative Commons license).

3. Flooding. When precipitation returns after a drought, it often falls on land that is too dry to hold it. Droughts don’t end sooner when rain falls fast—heavy rains pile huge amounts of water on top of hardened soil that cannot absorb it. Soil needs time to recover after a drought, but the gentle, soaking rains that do the most good for drought recovery aren’t usually the rains that first arrive. Droughts are frequently broken by floods, not relief.

Flooding in Cedar Rapids, Iowa

Flooding in Cedar Rapids, Iowa, June 2008. Photo Credit: Don Becker, U.S. Geological Survey (Used under Creative Commons license).

4. Disease. Both droughts and floods can create conditions favorable to the spread of disease among plants, animals and people. Droughts weaken the ability of crops and animals to resist disease—any living creature suffering from thirst and hunger is extremely vulnerable to disease. Conversely, floods are a perfect medium to spread viral and bacterial diseases. Floodwaters contain a wide array of contaminants from petroleum to human waste, making floods a highly efficient method of contaminating both soil and drinking water.

Flooding in Madagascar

Floods pollute water sources near an evacuation center in Madagascar, creating an urgent need for safe drinking water. Photo Credit: European Commission Humanitarian Aid and Civil Protection (Used under Creative Commons license).

The drought cycle’s quickening pace

Drought trend graph

Unfortunately, droughts are unavoidable. There will always be droughts, and droughts are a part of nearly every climate on Earth.

But droughts are outliers. That is, they are events that reside outside a long-term average. So while they may not be unusual, they are still rare. They are an expected and typical part of climate—but something we should see only a handful of times in a century. What we are seeing now is the beginning of an era when “drought” is becoming normal.

Climate change means that the characteristics of drought are changing. Conditions that were rare are becoming increasingly common. Events that occurred once a century will, in the near future, occur every few decades or even every few years. What our grandparents called “drought,” our great-grandchildren might call “August.”

In the 21st century, we’ve already seen droughts come more frequently, go deeper and last longer. That means that each drought is causing more damage—and giving people and nature less time to recover in between droughts.

This graph (left) shows how, since 1700 in California and Nevada, droughts have been getting deeper and longer. The current drought in California is the most extreme the state has experienced since 1895 . This trend is expected to continue and intensify for the foreseeable future.

A grasshopper. Photo Credit: siamesepuppy (Used under Creative Commons license).

The effects on human society

Agriculture: Droughts are often illustrated on the nightly news by images of dry fields filled with brittle stalks of corn or by herds of starving cattle on dusty plains. Certainly short-term revenue losses due to crop failure and increased costs for irrigation are familiar symptoms of drought, as are increased costs of food for consumers.

But drought also costs producers for years to come because of increases in insurance premiums, which can sometimes drive small farmers out of business altogether.

Economy: A number of industries—forestry, transportation, hydroelectric power generation, and recreation and tourism—directly suffer in times of drought. Companies in those industries may have to lay off workers or close permanently. Drought also often brings a widespread economic downturn. When resources like food and water are in short supply, their prices spike. And that leaves less money to spend in other economic areas, weakening the economy across the board.

Communities: At a minimum, droughts increase stress within a community because they cause economic uncertainty. Depending on the intensity, location and duration of a drought, a wide range of other serious events can occur. Reduced water levels and degraded water quality spread disease. Increased amounts of dust can lead to respiratory problems. Dry lands can erupt into grass and forest fires, setting off a new set of ecological, health and economic problems. And entire communities can be uprooted when people abandon their homes for other places. Although many of these symptoms of drought may seem extreme, they are more common than many people realize.

When evolution can’t keep up


A warning sign at Almaden Lake, California, alerts people to the toxicity of the blue-green algae bloom caused by the ongoing drought in August 2010. Photo Credit: Don Debold (Used under Creative Commons license).

Just as drought devastates human-tended plants and animals, it can lead to dry, unproductive forests, grasslands and wetlands, too. In general, native plants and animals are more resistant than domesticated species to the periodic drought conditions that effect their particular ecosystem. On the North American Great Plains, for example, many plant species have evolved to take advantage of prairie fires. Not only do these native grasses survive in dry weather, they thrive in it—and sometimes even require it.

Plant species like corn and wheat, on the other hand, were domesticated, refined and propagated as food by humans. They were designed to thrive in climactic conditions that are quite different from the arid and semi-arid climactic zones of western North America. And so they require far more water than native plants. These crops haven’t adapted to the landscape they’re planted in—people adapted the landscape to suit the plants’ needs. We have a lot invested in (and riding on) the ability of these plants to flourish.

Wild native plants have far fewer people tending to them, but they have the advantage of having adapted to the climates they’re found in. And, for species in arid and semi-arid climates, those climates include sometimes long, sometimes severe droughts. These species have survived for eons because they were able to withstand the worst their corners of the world could dish out.

But what happens when drought conditions exceed what plants and animals have adapted to? It may be happening already. Wild plants and animals that can survive the worst are now beginning to encounter circumstances that are worse than the worst.

When ecosystems change, the plants and animals inhabiting those ecosystems have to adapt. If they cannot, they become extinct. The problem we are likely to face in the 21st century is that the climate is changing too rapidly for many species to keep pace. Due to a number of factors—including habitat loss, pollution, rising sea levels and warming temperatures—an alarming number of species are critically endangered or have gone extinct in just the last few decades.

Drought is an event that puts every species under a great deal of strain. But as droughts intensify, wild animals and plants may end up being hit harder than domesticated species. It is understandable that people’s first concern is usually maintaining our own communities’ food supplies. But it is important, too, to preserve the ecological heritage of native plants and animals.