Today’s popular media and scientific journals are filled with dire predictions about the year 2050 and beyond. Increasing CO2 emissions may raise the planet’s temperature by 2 degrees Celsius or more. The world population could stand at as high as 10 billion people in 40 years, putting a huge strain on dwindling resources.
These two factors—climate change and rapid population growth—are interrelated, and combined they pose a major threat to global health. If unchecked, they’ll lead to drought, starvation, disease, and dislocation that will affect millions across the globe. And although people will suffer everywhere, the poorest nations and individuals will be particularly vulnerable.
But these catastrophic outcomes aren’t inevitable. There is still a lot of low-hanging fruit—simple measures that can have a positive impact in reducing climate change, slowing population growth, and improving health outcomes today and in the future.
Not just bad weather
According to Kirk R. Smith PhD ’77, MPH ’72, professor of global environmental health, the health impacts of climate change can be divided into three categories. First, there are the direct impacts: As global warming triggers heat waves and stronger storms, populations in affected areas will suffer the consequences. Deaths and health problems caused by heatstroke and storm-related injuries, damage, and property loss will rise.
Next, there’s a second level of effects brought on by changes in the natural environment. For example, a warming planet and shifting precipitation patterns can allow diseases like malaria to spread further and faster.
These effects will have the greatest impact on populations that are already vulnerable to disease, particularly poor children in developing parts of the world. “Climate change doesn’t invent any new diseases,” says Smith. “It works to exacerbate existing diseases, especially for those parts of the world that already have a high background rate. To put it bluntly, if you doubled child deaths from diarrhea in Berkeley, you’d probably have to wait five years to find one extra death. If you doubled child deaths from diarrhea in Zimbabwe, you’d get 50,000 the first year.”
Climate change’s third level of impact involves effects that operate through human agency, such as food price increases. The environment affects how societies produce and distribute food, as well as human migration patterns. For example, global warming causes water shortages and sea level increases in some areas, which in turn creates refugee populations and camps that spread disease more rapidly.
But the largest threat Smith sees is malnutrition. “Changes in agricultural production and their effects on food prices will mean fewer people can afford the food they need,” he says. “Both the World Health Organization and the Intergovernmental Panel on Climate Change have estimated that malnutrition will be the biggest health impact from climate change.” Hunger’s effect, however, isn’t easy to quantify. “Predicting the malnutrition impacts of climate change is tricky,” says Smith. “You have to project not only the effects on agricultural production, but also how society responds. But society hasn’t shown much ability to deal with the current misdistribution of food worldwide, so there’s no reason particularly to think it’s going to do better in the future.”
Despite the prospect of climate change impacting their people’s health, nations have been slow to respond to it. Smith believes there are two main reasons for this. First, although global warming will seriously impact them in the long run, governments—especially those of developing countries—often face more pressing issues. They need to improve economic output, increase the number of jobs, and tackle existing health problems, for example. Second, because climate change and its effects are so complex, some people still doubt a direct connection between human activities, such as burning fossil fuels, and environmental problems like regional droughts.
To help overcome resistance to tackling environmental change, Smith has spent much of his career examining the issue of co-benefits. “One way to frame this is just because climate change has come along doesn’t mean that the old problems have gone away,” he says. “But there are ways that you can move toward both the goal of solving those traditional issues and reducing environmental impact at the same time.”
“We used to call this a ‘no-regrets’ strategy,” he adds. “When we encourage policies that give a short-term health benefit in the context of a longer-term potential benefit for climate, there are no regrets. Even if the climate benefit turns out to be not so important, still you’ve gotten the short-term benefit.”
One example of a co-benefits program Smith points to is his work to reduce the negative health consequences of household combustion. Home cookfires and wood- and charcoal-burning stoves are a leading cause of respiratory issues in many parts of the world.
Because they produce substantial particulate pollution and CO2, often in poorly ventilated rooms, these stoves and cookfires are a double threat. Women and children who spend a lot of time indoors and breathe the particulate matter are susceptible to breathing problems, and greenhouse gas emissions increase global warming.
To combat these effects, Smith and colleagues have focused on developing and providing low-emissions stoves to families in developing parts of the world. “You can increase combustion efficiency in two ways, either by using better stoves or better fuels,” says Smith. “You not only get a health benefit of a substantial size, but also an environmental benefit, a reduction in the risk of climate change.”
Working with a group of private companies and Sri Ramachandra University in Chennai, India, Smith and a team at the UC Berkeley School of Public Health recently developed wireless monitors to transmit stove usage data that help researchers assess effectiveness of the stoves and the programs to disseminate them. The project, which won the first-place $300,000 prize in the 2010 Vodaphone Americas Foundation Wireless Innovation Project, is part of Smith’s efforts to provide a co-benefits program that can positively impact both public health and the environment in many parts of the world.
Another example of a “no-regrets” strategy Smith points to is giving women access to contraceptives. “When that happens, there’s an immediate health benefit because the two groups that most want to control their fertility are young, unmarried women and older women,” he says. “These are also the two groups that have the highest rates of infant and maternal mortality.” Longer spacing between births also has a direct health benefit to children. The co-benefit, he says, is the longer-term help for the climate. Fewer people mean fewer greenhouse gasses. A recent study published by the National Academy of Sciences found that holding population growth to 7.4 billion by 2050 could reduce output of carbon dioxide by up to 30 percent. “That’s a significant difference,” says Smith. “It shows that there are both health benefits and climate benefits from just giving women the right to choose how many children they have.”
The population divide
The relationship between reproductive rights and population growth is central for researchers at the School of Public Health’s Bixby Center for Population, Health, and Sustainability. Professor Malcolm Potts, the Bixby Center’s director, says that rapid population growth can be slowed and that making voluntary family planning universally available is the key to keeping the world sustainable during the next 40 years.
“The world is now very divided demographically,” he says. “There are a lot of countries, particularly in East Asia and the developed world, where women are having two children or fewer. But in a few countries, there is exceptionally rapid population growth. Almost 95 percent of population growth between now and 2050 will be in the least-developed nations, and most of it will be from unintended pregnancies.”
Potts believes that this division between the parts of the world that have moved toward a low growth rate and those where population is exploding—primarily in areas such as sub-Saharan Africa, Afghanistan, and Pakistan—is creating an unsustainable situation. “This division is very bad for the world,” he says. “It’s bad for the environment, and it’s bad for individual human beings, who are suffering a lot.”
The good news, however, is that it’s a problem with solutions. The Bixby Center has embarked on a number of research projects and initiatives to improve education about—and access to—sexual and reproductive health options. “The two billion people living on $2 a day or less are the ones who do not have access to the family planning services and information that they need, and they are having the unintended pregnancies,” notes Potts.
In Ethiopia, as in many parts of sub-Saharan Africa, a number of trends are exacerbating high population growth, poverty, and poor health outcomes. Growing urbanization, increasing incidence of premarital intercourse, and biases on the part of existing sexual health care service providers have combined to increase the number of unintended pregnancies and related morbidities and mortalities.
Karen Weidert MPH ’10, an associate specialist at the Bixby Center, is contributing to a survey of Ethiopian youth about their preferences for receiving sexual and reproductive health care services. The survey is aimed at discovering how to combat these trends and find the best ways to bring services to the people who need them most. “There’s a lot of effort and money going into different kinds of youth-friendly services,” Weidert says. “But there’s not a lot of evidence about what’s working. We see that some of these programs are developed without asking the youth what they want.”
Also in Ethiopia, Associate Professor in Residence Ndola Prata, the Bixby Center’s scientific director, is leading research on the efficacy of making injectable contraceptives more widely available. By training community members—rather than just doctors and nurses—to provide these contraceptives, women can have much greater access and are more comfortable about receiving them.
The Bixby Center is engaged in numerous other projects across sub-Saharan Africa as well—in Tanzania, Zanzibar, Ethiopia, and Nigeria—all aimed at improving reproductive health and access to family planning resources.
A choice for change
Potts believes that being empowered with regard to when and if to have children is a fundamental right. For Bixby Center members, this belief helps steer their work in reproductive health issues. “That’s a basic framework in which we work,” says Potts. “To respect people and let them make their own decision. If somebody wants to have six children, that’s fantastic. What we’re interested in is the woman who doesn’t want to have six children, but can’t exercise her right to have fewer children because she can’t get hold of the information and services.”
Weidert agrees. “We’re quite focused on women having a choice,” she says. “It’s their right to have a choice when and if they have children and how to space them.”
Despite the progress that’s being made, both Potts and Weidert stress that there’s a huge, unmet need for family planning that must be solved if global population is to be maintained at a sustainable level. They believe it is one of the top public health challenges today.
Thirty years ago, Potts was among the first researchers to sound the alarm about the potential devastation AIDS would cause in sub-Saharan Africa. He believes we are at a similar moment with regard to population control. “In the Sahel on the border of the Sahara there’s exceptionally rapid population growth—people are having six and seven children. You’ve got abject poverty and global warming is going to destroy what food production they have in an ecologically vulnerable region. I think in thirty years time there’s going to be as much suffering in that area from population pressure and climate change as there has been in the last thirty years from AIDS.”
Both Potts and Weidert stress the importance and urgency of giving priority to family planning. “All the evidence shows that when women are offered ways to limit their childbearing, family size falls,” says Weidert. “That’s the only way to reach sustainable population levels. We just have to continue increasing access to all forms of family planning, and give women the education and choices they need.”
Potts asserts that the Bixby Center and the School of Public Health can play an important role in helping the planet achieve a sustainable population and healthier future generations. “What a university can do is to get in there early, look at the numbers, and project what is going to happen,” he says. “We can design scientifically valid studies and then work with somebody to get those implemented. And then those people will take those studies to senior decision makers and try and change the policies.
“Sometimes it’s frustrating. You have to keep on knocking on the same door. But that’s how change is brought about. We’ve made it work in the past, and we’ll keep on working it in the future.”