The atmosphere is warming. Ice is melting. Droughts are worsening; seas are warming, rising and acidifying. We’re past theory and well into measurement on those points. Pope Francis recently observed that “[n]ever have we so hurt and mistreated our common home as we have in the last 200 years.” The matter of climate change is urgent, and it commands a moral dimension.

The United States has an especially strong responsibility to respond to this, the moral issue of our age. We have long been viewed globally as an exceptional country, with the world’s most powerful economy and military and a government that provides basic freedoms for its citizens. An American failure to lead on climate change will imperil our special status and dampen our global power to lead.

Climate change is causing irreparable harm to people who can least afford to respond. While upper-income societies can pay a greater share of their wealth for essentials as scarcity increases, marginal societies must go without. Their struggles – for water, farmland and fisheries – will be desperate, generating instability and conflict.

The US Department of Defense’s Quadrennial Defense Review (QDR) repeatedly raises this key threat. The 2010 QDR concluded that “[w]hile climate change alone does not cause conflict, it may act as an accelerant of instability or conflict, placing a burden to respond on civilian institutions and militaries around the world.” Four years later, the 2014 Review was just as straightforward in its warnings.

The most recent Intergovernmental Panel on Climate Change assessment echoes what our military and diplomatic leaders are saying about the dangers of climate change: “climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence by amplifying well-documented drivers of these conflicts such as poverty and economic shocks.”

A world of heightened competition, conflict and instability will lead to more human suffering, and open the door to greater instability and extremism.



As the country that generated the most wealth in the carbon economy, as the world’s most profligate emitter of carbon and as the essential nation upon which the world counts for leadership, we have a moral obligation to respond. America cannot avoid ownership of this challenge.



We are in a period of consequences. Yet we are in a period of political crisis at home. Carbon polluters are calling the tune in Congress; the present Republican party is unwilling or unable to stand up to the polluters; and a massive propaganda effort is churning full-steam to deny the carbon problem. The Obama administration has in the face of congressional dysfunction moved forward with new carbon pollution limits for power plants, and we applaud its efforts. But if we are to be seen as credible in the eyes of a world ravaged by the effects of climate change, Congress will need to step in and build upon those efforts to produce further reductions in emissions. And we will need to encourage international efforts to reach a climate agreement like those slated for Paris this year.

If you believe, as we do, that the world needs America – if you believe, as we do, that America is the essential and exceptional nation – then getting climate right matters. A world fouled and changed by carbon pollution, in ways many in Congress foresaw but ignored, will not believe it has much need for the example America claims to offer. As Pope Francis said, “Those who will have to suffer the consequences of what we are trying to hide will not forget this failure of conscience and responsibility.”

Failing to lead at this moment of necessity will soon and long darken the lamp America holds up to the world. And the tide that has quietly sustained us could begin to shift.