Bringing half the world’s population out of poverty will also lead to an increase in carbon emissions.

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Fighting poverty might make it harder to fight climate change

Lifting people out of poverty is a noble goal, but it could make it harder to fight climate change. That’s the conclusion of a new study, which finds that elevating the world’s poorest individuals into the middle class would significantly increase carbon emissions, requiring greater efforts to combat global warming.

One in five people in developing nations lives on less than $1.90 a day, where they lack basic needs such as food and water and have limited access to education. Most are found in southern Asia and sub-Saharan Africa. In 2014, the United Nations agreed on a list of sustainable development goals, the first of which is to “end poverty in all forms everywhere.” The agenda set targets to eradicate extreme poverty by 2030. A year later, the United Nations Framework Convention on Climate Change set a goal to keep global warming below 2°C above preindustrial levels.

Klaus Hubacek, an ecological economist at the University of Maryland in College Park, and his colleagues wondered whether these two initiatives might be in conflict. As people earn more money, they spend it on things like travel that increase the amount of carbon dioxide and other greenhouse gasses pumped into the atmosphere. Climate change and poverty—“these are really the two most important questions humanity faces,” he says.

To see whether the United Nations’s goal to eliminate poverty and stay within 2°C of warming could both be achieved, the researchers modeled two scenarios: one that just brought the world’s poorest out of extreme poverty, and the other raised them to a modest level of income. Then they calculated the carbon footprints for each income group before and after, based on the World Bank’s Global Consumption Database.

Fighting poverty might make fighting climate change harder, the team found. Eradicating extreme poverty, defined as living on less than $1.90 per day, doesn’t jeopardize the 2°C climate target, the team reports today in Nature Communications. Doing so is projected to contribute just 0.05°C in additional warming by the end of the century. However, bringing the world’s poorest to the next income level—the global middle class average income of $2.97 per day—would add another 0.6°C to the already projected 2°C of warming by 2100.

The study implies that climate and human development goals are not necessarily inconsistent, but “It really kind of depends on what level of poverty we’re OK with,” says Steve Davis, an earth systems scientist at the University of California, Irvine, who was not involved with the work. The bottom line, he adds: “If we’re really trying to consider getting people not just out of extreme poverty, but into the middle class, then maybe we do have more of a challenge.”

Lifting everyone to the global middle class would require a 27% increase in efforts to reduce carbon emissions, compared with the 4% per year required without poverty reduction goals. But even the most ambitious countries, such as Sweden, have achieved little more than a 4% reduction per year, doing so by replacing fossil fuels with nuclear energy and hydropower.

However, the technologies that exist have been unable to keep up with additional emissions so far, the authors say. Davis says the pace will pick up if and when clean energy becomes cheaper than fossil fuels. In the meantime, Hubacek and his colleagues call for lifestyle changes, such as switching to a vegetarian diet, using public transportation, traveling less or shorter distances, and living in smaller houses. Although individuals, cities, and states can take action to reduce carbon emissions, Hubacek says massive involvement is needed by the state as well, like implementing a carbon tax. “Time is really running out.”