In facing climate change, what we already know requires a response; it cannot be easily dismissed. Significant levels of scientific consensus—even in a situation with less than full certainty, where the consequences of not acting are serious—justifies, indeed can obligate, our taking action intended to avert potential dangers. In other words, if enough evidence indicates that the present course of action could jeopardize humankind's well-being, prudence dictates taking mitigating or preventative action.
Nearly twelve years ago, the U.S. Catholic bishops emphasized the virtue of prudence in addressing climate change—and this when the scientific consensus around climate change was at a more nascent stage than it is now. Today, as NASA reports, 97% "of climate scientists agree that climate-warming trends over the past century are very likely due to human activities, and most of the leading scientific organizations worldwide have issued public statements endorsing this position." The evidence is now crystal clear, and the only question is: How bad is it going to get?
When the bishops wrote their statement, CO2 concentrations—the primary forcing agent for climate change—was around 365 parts per million (ppm). In a little more than a decade, humankind has increased this to nearly 400 ppm and at current rates, that will reach 450 ppm by mid-century.
Scientists believe that the last time concentrations were this high was during the Pliocene epoch, around 3 million years ago, a time when the Earth’s average temperatures were 5-7 degrees Fahrenheit warmer than they currently are and sea levels were nearly 80 feet higher than they are today. Since that period, scientists believe that naturally changing ocean patterns may have contributed to the significant decrease of atmospheric CO2, and a subsequent decline in global temperatures. Whatever the cause of this CO2 reduction, atmospheric CO2 concentrations stabilized at around 280 parts per million around 10,000 years ago, and lasted until the dawn of the industrial revolution in the 1800s—the time when humanity began releasing unprecedented amounts of greenhouse gases as fossil fuels became the predominant form of energy.
These new CO2 numbers, while not unexpected given the continued reliance on coal, oil, natural gas and other fossil fuels in our economy, are of tremendous concern to climate scientists. Most believe that concentrations must come down to 350 ppm by 2050 in order to avoid runaway and irreversible climate change.
Many hope for some technological fix that will magically appear and suck carbon out of the atmosphere. However, “what we already know requires a response” and that response must begin today in the absence of any such technology on the horizon. That response must include fairly dramatic shifts in lifestyle and consciousness choices—especially on the part of Christians and other people of goodwill. Those choices must include consuming less, living more simply and internalizing a type of solidarity that recognizes that the misery felt by current and future generations facing massive changes in weather patterns is caused by our failure to choose consciously today.
This call to respond is not new. In 1990, Pope John Paul II first brought climate change to the attention of Catholics when he recognized in his 1990 World Day of Peace Message, “The gradual depletion of the ozone layer and the related ‘greenhouse effect’ has now reached crisis proportions.”
Similarly, Pope Benedict XVI, several national Catholic bishops’ conferences, numerous Catholic NGOs and Catholic scholars, and the Catholic Coalition on Climate Change have called for faithful climate action and linking these actions to the wonderful tradition of Catholic social teaching including the Catholic commitments to protect and defend human life and dignity and care for God’s good gift of Creation as well as recognizing that those who have contributed the least to climate change are now and will continue to face its worst consequences: the poor and vulnerable.
In 2006, the USCCB helped formed the Catholic Coalition on Climate Change and charged the membership organization to educate and organize the U.S. Catholic community to respond faithfully to climate change. Key to that effort has been The St. Francis Pledge to Care for Creation and the Poor, encouraging individuals, families, parishes, schools and other organizations to:
PRAY and reflect on the duty to care for God’s Creation and protect the poor and vulnerable.
LEARN about and educate others on the causes and moral dimensions of climate change.
ASSESS how we-as individuals and in our families, parishes and other affiliations-contribute to climate change by our own energy use, consumption, waste, etc.
ACT to change our choices and behaviors to reduce the ways we contribute to climate change.
ADVOCATE for Catholic principles and priorities in climate change discussions and decisions, especially as they impact those who are poor and vulnerable.
In his Letter to the Ecumenical Patriarch of Constantinople on the Occasion of the Seventh Symposium of the Religion, Science, and the Environment Movement, Pope Benedict XVI declared, “Preservation of the environment, promotion of sustainable development and particular attention to climate change are matters of grave concern for the entire human family.” Now that the atmospheric concentration of CO2 is on the verge of surpassing 400 ppm, humanity has a rapidly-closing window of opportunity to prevent runaway and irreversible climate change. Committing to consistent and conscious individual actions and devoting our vast institutional resources to this problem can be delayed no longer. We must act and we must do so not because it is trendy but because our faith demands it.
Daniel J. Misleh is Executive Director of the Catholic Coalition on Climate Change. Daniel R. DiLeo is Project Manager of the Catholic Coalition on Climate Change and a Ph.D. student in Theological Ethics at Boston College