On behalf of the Dialogue on Science, Ethics, and Religion (DoSER) program at the American Association for the Advancement of Science (AAAS) -- the world's largest general scientific society, representing some 10 million individual scientists worldwide -- I strongly commend Pope Francis' Encyclical, "Laudato Si'," which reaffirms the reality of human-induced climate change, and calls for action.
Pope Francis correctly noted that "a very solid scientific consensus indicates that we are presently witnessing a disturbing warming of the climatic system." Indeed, the nonprofit, nonpartisan AAAS has repeatedly cautioned that climate change related to fossil-fuel burning and deforestation is real. In the 3 July 2015 issue of Science, AAAS' flagship publication, Editor-in-Chief Marcia McNutt applauded Pope Francis' efforts, saying he is "currently our most visible champion for mitigating climate change." It is happening here and now, and the sooner we take action, the better off we will be.
The Pope's Encyclical reflects a growing and important relationship between religious leaders and the scientific community, one that DoSER has actively supported for 20 years by facilitating conversations between scientists and religious communities. The importance of this kind of dialogue for environmental stewardship can be seen in the enthusiasm of participants in DoSER symposia such as "Partners for the Earth" and the national "Perceptions" project (which sought to improve cross-community dialogue on issues including environmental care by investigating the perceptions that scientists and religious communities hold about one another).
These efforts, along with similar initiatives in multiple faith communities, are signals of hope that society at large can respond effectively to the environmental alert so clearly proclaimed by Pope Francis. With the growing recognition that the world's poor will suffer the most from the impacts of climate change, as noted powerfully in the Encyclical, concern is building, motivating action and communication between scientists and religious communities in a common quest to change the current disturbing environmental trajectory.
In fact, 2015 marks the 50th anniversary of the first official climate-change warning made to a U.S. President. That document, submitted to Lyndon B. Johnson on November 5, 1965 by the President's Science Advisory Committee (now known as the President's Council of Advisors on Science and Technology (PCAST), concluded that continued accumulation of atmospheric carbon dioxide resulting from fossil-fuel burning would "almost certainly cause significant changes in the temperature and other properties of the stratosphere." The committee noted further that such changes "could be deleterious from the point of view of human beings."
Fifty years later, the reality of human-caused climate change has been reaffirmed by virtually every leading scientific organization, as well as the vast majority of individual climate scientists worldwide.
For example, the AAAS Board of Directors has stated that "the scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society." Since the nineteenth century, atmospheric carbon-dioxide has continued to rise, trapping heat near the Earth's surface. Over the last 100 years, the atmosphere has warmed by 1.4 degrees Fahrenheit, and it is projected to rise by another 4 to 8 degrees F before the year 2100, according to the AAAS "What We Know" report.
The disruption of Earth's climate envelope has caused an acceleration in the loss of Arctic sea ice; the melting of the Greenland and Antarctic ice sheets; ocean acidification; harmful impacts to animals and plants; sea-level rise; an increased risk of floods, heat waves, droughts, wildfires, and intense storms; and threats to national security as well as human health. All of these changes will have a disproportionately negative impact on the lives of people with the fewest resources.
The 50th anniversary of the first PCAST climate-change warning, and the upcoming U.N. summit on climate change, represent important opportunities for inspiring positive change. The Pope's Encyclical was an excellent reminder of the broad concern - not just among scientists, and not just for Catholics, but across society -- about the buildup of greenhouse gases in our atmosphere.
For its part, AAAS has teamed up with the Carnegie Institution for Science and the American Meteorological Society to host a daylong symposium on October 29 on what scientists have learned about climate change, the questions that remain unanswered, and the promise of science and technology to address the challenges that lie ahead. This promise will be most fully realized in the context of shared values and commitment of a wide swath of society. As Pope Francis so aptly points out, "we have to realize that a true ecological approach always becomes a social approach; it must integrate questions of justice in debates on the environment, so as to hear both the cry of the earth and the cry of the poor."