How to achieve a path to sustainable development is the most important problem facing the world today. It is a phenomenal challenge, unique for our time, and the voice of the church will be central for success. There is no possibility for success unless the world unites in an ethical vision defending humanity and nature. The social doctrines and moral teachings of the church are vital in building that ethical framework.

There was a moment in history, 50 years ago, when the voice of the church helped save the world. In April 1963, Pope John XXIII published “Pacem in Terris,” his last encyclical. It called on all governments around the world to exercise political power in a context of morality and human survival, and it helped inspire and encourage President John F. Kennedy to give the most important speech of the modern American presidency, known as his “A Strategy of Peace” address, at American University in June 1963. The encyclical, combined with the speech, helped pave the way for the Partial Nuclear Test Ban Treaty, signed with Premier Nikita Khrushchev of the Soviet Union in July 1963, a crucial step back from the brink of nuclear annihilation.


This historical case is a vivid example of how the words and vision of the church can help inspire global leadership on a pressing issue. I believe the same inspiration by the church is necessary for tackling today’s challenge of sustainable development. We have entered an era of human history that requires new approaches and solutions. If they are to galvanize the necessary human action around the world, this fresh approach must be grounded in a new global ethic. At this point, however, we lack both the tools and the universal moral language for this monumental task.

Indeed, we are drifting rather than solving problems, and we are losing time. In his inaugural address in 1961, President Kennedy said, “Man holds in his mortal hands the power to abolish all forms of human poverty, and all forms of human life.” We still hold in our hands the ability to eradicate poverty, and we are indeed making some important progress. Yet we still threaten human life, not only through nuclear weapons and other armaments, but also through our wanton destruction of the natural environment. We must understand our predicament in order to reorient our actions.

Achievements and Challenges

Let me begin with some good news: the rate of global poverty is falling rather rapidly. In 1980 around 55 percent of the households of the developing countries lived in extreme poverty, as measured by the World Bank. By 1990 the poverty rate had declined to around 44 percent, and by 2010 to around 21 percent. In short, the world has succeeded in achieving the Millennium Development Goal to cut the poverty rate by half between 1990 and 2015. Indeed, taking the developing world as a whole, we are ahead of schedule. We still have the urgent task in the years ahead to ensure that all regions, especially sub-Saharan Africa, the world’s poorest, share fully in the progress.

Even with this important news, the challenges remain profound: not only to complete the task of ending poverty, but also to ensure a just and environmentally sustainable economy.

In my travels on behalf of Ban Ki-moon, the secretary general of the United Nations, I have encountered massive street protests—in Istanbul, Rio de Janeiro, Santiago and even my home city, New York, with the Occupy Wall Street movement. This unrest is not a phenomenon limited to any city, country, region or level of development. It is a worldwide phenomenon of instability. It reflects a crisis of youth, unemployment, insecurity, inadequate or corrupt governance and rising inequalities. It is a global crisis of legitimacy and justice.

Youth unemployment is certainly one of the greatest scourges. The youth unemployment rates in many parts of Europe have reached 20 percent or 30 percent, and more than 50 percent in Spain. Youth unemployment in North Africa, which is in upheaval, is between 30 percent and 50 percent. In Latin America it is between 20 percent and 30 percent. In all parts of the world, we face a job crisis brought on by technological change. Young people are not equipped with the education and training they need to find jobs that can give them security and enable them to raise families.

The challenges extend beyond the economic and social realms. We must also address the rising environmental threats. Ecological change is dramatic yet poorly perceived. The human population has become so numerous—7.2 billion people today and perhaps around 11 billion by the end of the century—with human beings on average using so many of the earth’s resources at a pace that threatens to undermine fundamental balances involving the earth’s climate, the water cycle, the nitrogen cycle, ocean chemistry and the habitat for millions of other species. Scientists have even given our age a new scientific term: the Anthropocene (Greek for “human epoch”). Human, here, is used in a scientific manner, to refer to the fact that human beings have become the main sources of environmental change and destruction on a global scale. It is not a happy term.

Humanity is not driving these fundamental changes with any sense of responsibility or even with much awareness, in part because the scale of environmental change is completely unprecedented. Our societies, cultures, economic practices and political institutions have been unable so far to face up to the threats of climate change, ocean acidification, deforestation and other profound dangers. But the pace of environmental change is extraordinary, putting humanity in imminent peril in a matter of decades, not centuries.

For a stark example, consider the level of carbon dioxide in the atmosphere during the last 800,000 years (see the graph on pg. 14). We care about carbon dioxide since it is the most important greenhouse gas, the kind that leads to global warming. The carbon cycles in the distant past were caused by orbital changes of the earth. Looking at the far right of the graph, we see that the carbon cycle has recently veered off its past course. Levels of carbon dioxide are soaring. In April 2013 it reached a concentration of 400 parts per million, not seen on earth for three million years. The cause is the massive use of coal, oil and gas for worldwide energy. The grave danger of this reliance on fossil fuels is massive and destructive climate change.

The environmental threats, alas, do not end there. World-leading ecologists have identified nine planetary boundaries—climate change, ocean acidification, overuse of fresh water, nitrogen and phosphorus pollution, ozone depletion, destructive land-use change, loss of biodiversity, aerosol pollution and chemical pollution—where human actions now threaten to destabilize the planet. We need urgently to ensure that our technologies and resources are compatible with a safe and sustainable planet.

The dangers are increasingly apparent in our daily lives. We are setting records for heat waves, droughts, floods and other extreme weather. In 2012 the United States had the worst floods and worst drought in decades and the highest temperatures on record. Yet the consequences are even more terrifying in the poorest regions of the globe. From 2010 to 2011, the Horn of Africa was gripped by an extreme drought. Many people perished. Violence and conflict flared. Last year the drought was in the Sahel region of West Africa. Again, hunger and drought were tinder for violence, contributing to the civil war in Mali.

Goals and Ethics

So what must we do? We need a change of direction in our policies and economic organization. The concept I have long found to be the most fruitful for organizing thinking on how to change is the concept of sustainable development. This concept calls for a holistic approach to society’s challenges, rather than a single-minded pursuit of economic growth. This holistic approach combines economic development, social inclusion, environmental sustainability and good governance.

The world’s governments have adopted sustainable development as the organizing principle for global development following the Millennium Development Goals period. In the important Rio+20 Summit in June 2012, the governments declared their intention to adopt Sustainable Development Goals to help harness the world’s energies toward this historic challenge. At the conclusion of the summit, they adopted “The Future We Want,” which describes the world’s sustainable development priorities and how a set of development goals can help to meet them.

The U.N. member states will select the new goals by 2015. These are likely to include the challenges of ending extreme poverty, extending quality education to all children, eliminating gender and ethnic discrimination, fighting climate change, promoting decent work, ensuring food security and making our cities more livable and resilient to hazards. The first intergovernmental meeting on the new goals took place at the U.N. General Assembly on Sept. 25.

The new goals, however, will not succeed unless we have a global ethical framework to underpin them. While the challenges of sustainable development are technical to a significant extent—for example, how to make the transition to a low-carbon economy—the challenges are also fundamentally a matter of ethics. Unless we have a shared moral understanding of what it means to take care of the poor, one another and the planet, there is little prospect of turning stated goals into reality.

The social doctrine of the church offers a critical and unique pathway to a global ethic of sustainable development. In my work on sustainable development, I refer to the compelling teachings of the church, like the preferential option for the poor, the universal destination of goods, placing private property within a moral framework and Pope Paul VI’s still relevant message, “Development is the new name for peace.”

The church speaks movingly about our responsibilities toward creation, charity in truth and subsidiarity in good governance. These wise teachings are, of course, only a small part of the social doctrine of the church. They inspire us and point the way toward a universal ethic, with the human being at its core. They can help shape a global dialogue across religions and regions, since they embody deep human yearnings of a universal character.

We need a massive change of direction worldwide in a very short period of time. Secretery General Ban Ki-moon has asked me to establish a global knowledge network on sustainable development, called the Sustainable Development Solutions Network, involving universities around the world, research institutes, businesses, foundations and scientific academies, to bring together world leaders in science, engineering, economics, finance, ecology and related fields to help brainstorm practical solutions. I hope that the network and the Pontifical Academy of Science can find ways of fruitful and exciting collaboration as we move ahead.

As I travel the world and meet with government leaders, I find time and again that no government is yet equipped for the serious challenges we face, but the goodwill to take on these challenges can be found in all parts of the world and in all societies. Many political obstacles and vested interests hamper progress, and there are many causes for confusion and immobility. Yet there is a deep yearning for a shared global effort.

Can the world achieve sustainable development? The answer is certainly yes. We have the know-how. Even within the short time span that remains before 2050, we can make a radical transition to safe energy. By 2030 we can end extreme poverty, strengthen communities and ensure that every child can get a healthy start and a good education. We can also advance a new global ethic, drawing on the great social teachings of the church and other great traditions.

The choice, of course, is ours. Most important, we need to understand that humanity is bound together in a common fate. And in this regard, let us end where we began, with the speech President Kennedy made at American University. He sought to convince Americans that it would be possible to find common ground with the Soviet Union, something unimaginable for many Americans at the time. His message, drawing inspiration from Good Pope John, was that peace was indeed possible because the other side was human too, with the same hopes and dreams as Americans. President Kennedy expressed this conviction with these words of sublime eloquence:

Let us not be blind to our differences— but let us also direct attention to our common interests and to the means by which those differences can be resolved. And if we cannot end now our differences, at least we can help make the world safe for diversity. For, in the final analysis, our most basic common link is that we all inhabit this small planet. We all breathe the same air. We all cherish our children’s future. And we are all mortal.