NEW YORK – The year 2015 will be our generation’s greatest opportunity to move the world toward sustainable development. Three high-level negotiations between July and December can reshape the global development agenda, and give an important push to vital changes in the workings of the global economy. With United Nations Secretary-General Ban Ki-moon’s call to action in his report “The Path to Dignity,” the Year of Sustainable Development has begun. In July 2015, world leaders will meet in Addis Ababa, Ethiopia, to chart reforms of the global financial system. In September 2015, they will meet again to approve Sustainable Development Goals (SDGs) to guide national and global policies to 2030. And in December 2015, leaders will assemble in Paris to adopt a global agreement to head off the growing dangers of human-induced climate change. The fundamental goal of these summits is to put the world on a course toward sustainable development, or inclusive and sustainable growth. This means growth that raises average living standards; benefits society across the income distribution, rather than just the rich; and protects, rather than wrecks, the natural environment. The world economy is reasonably good at achieving economic growth, but it fails to ensure that prosperity is equitably shared and environmentally sustainable. The reason is simple: The world’s largest companies relentlessly – and rather successfully – pursue their own profits, all too often at the expense of economic fairness and the environment. Profit maximization does not guarantee a reasonable distribution of income or a safe planet. On the contrary, the global economy is leaving vast numbers of people behind, including in the richest countries, while planet Earth itself is under unprecedented threat, owing to human-caused climate change, pollution, water depletion, and the extinction of countless species. The SDGs are premised on the need for rapid far-reaching change. As John F. Kennedy put it a half-century ago: “By defining our goal more clearly, by making it seem more manageable and less remote, we can help all people to see it, to draw hope from it, and to move irresistibly toward it.” This is, in essence, Ban’s message to the UN member states: Let us define the SDGs clearly, and thereby inspire citizens, businesses, governments, scientists, and civil society around the world to move toward them. The main objectives of the SDGs have already been agreed. A committee of the UN General Assembly identified 17 target areas, including the eradication of extreme poverty, ensuring education and health for all, and fighting human-induced climate change. The General Assembly as a whole has spoken in favor of these priorities. The key remaining step is to turn them into a workable set of goals. When the SDGs were first proposed in 2012, the UN’s member said that they “should be action-oriented,” “easy to communicate,” and “limited in number,” with many governments favoring a total of perhaps 10-12 goals encompassing the 17 priority areas. Achieving the SDGs will require deep reform of the global financial system, the key purpose of July’s Conference on Financing for Development. Resources need to be channeled away from armed conflict, tax loopholes for the rich, and wasteful outlays on new oil, gas, and coal development toward priorities such as health, education, and low-carbon energy, as well as stronger efforts to combat corruption and capital flight. The July summit will seek to elicit from the world’s governments a commitment to allocate more funds to social needs. It will also identify better ways to ensure that development aid reaches the poor, taking lessons from successful programs such as the Global Fund to Fight AIDS, Tuberculosis, and Malaria. One such innovation should be a new Global Fund for Education, to ensure that children everywhere can afford to attend school at least through the secondary level. We also need better ways to channel private money toward sustainable infrastructure, such as wind and solar power. These goals are within reach. Indeed, they are the only way for us to stop wasting trillions of dollars on financial bubbles, useless wars, and environmentally destructive forms of energy. Success in July and September will give momentum to the decisive climate-change negotiations in Paris next December. Debate over human-induced global warming has been seemingly endless. In the 22 years since the world signed the UN Framework Convention on Climate Change at the Rio Earth Summit, there has been far too little progress toward real action. As a result, 2014 is now likely to be the warmest year in recorded history, a year that has also brought devastating droughts, floods, high-impact storms, and heat waves. Back in 2009 and 2010, the world’s governments agreed to keep the rise in global temperature to below 2° Celsius relative to the pre-industrial era. Yet warming is currently on course to reach 4-6 degrees by the end of the century – high enough to devastate global food production and dramatically increase the frequency of extreme weather events. To stay below the two-degree limit, the world’s governments must embrace a core concept: “deep decarbonization” of the world’s energy system. That means a decisive shift from carbon-emitting energy sources like coal, oil, and gas, toward wind, solar, nuclear, and hydroelectric power, as well as the adoption of carbon capture and storage technologies when fossil fuels continue to be used. Dirty high-carbon energy must give way to clean low- and zero-carbon energy, and all energy must be used much more efficiently. Jeffrey D. Sachs is Professor of Sustainable Development, Professor of Health Policy and Management, and Director of the Earth Institute at Columbia University. He is also Special Adviser to the United Nations Secretary-General on the Millennium Development Goals.