Click here if you don’t see subscription options
Elizabeth GroppeDecember 12, 2011

We are here in Panama,” stated Naderev Sano, “to tell the world that climate change is a matter of life and death for the Philippines.” Sano is commissioner of the Filipino Climate Change Comission, and he spoke these words at a meeting held in preparation for the UN meeting on climate change, which opened in Durban, South Africa on November 28. Although Catholics may not usually think of climate stabilization as a pro-life issue, it is increasingly clear that protecting the sanctity of life means not only working to end abortion and the death penalty but also acting to conserve the earth’s climate and biosphere.

The world’s most prestigious scientific bodies are in agreement that global warming is a reality caused primarily by human beings and that its consequences on our economy and environment will be far-reaching. In the short term, climate change will bring an increase in extreme weather events that threaten human populations and agricultural production. In the long term, the very viability of human civilization is at stake.   

The climate is changing because of the “greenhouse effect,” a phenomenon by which heat-trapping gases in the atmosphere retain the infrared radiation reflected when the sun’s rays touch the earth’s surface. Were it not for some level of atmospheric greenhouse gas, the planet would be too cold to support life as we know it. But our combustion of fossil fuels, our razing of forests and our agricultural practices have elevated the atmospheric concentrations of the greenhouse gases carbon dioxide, methane and nitrous oxide. Prior to the industrial revolution, atmospheric carbon dioxide was 280 parts per million (ppm). Today it is 391 ppm and rising by about 2 ppm each year. Between 1900 and 2009, the global average surface temperature rose 1.3 degrees Fahrenheit.

This may sound negligible. But the global climate is a very complex reality in which a small change in average temperature has ripple effects on ocean currents, precipitation patterns and other climate systems. An apparently small temperature increase is already destabilizing the energy balance of the climate and spawning changes adverse to human beings and other species. Impacts can be seen in many areas, including the following:

Agriculture. Plants are very sensitive to changes in temperature and precipitation patterns. Between 1980 and 2008, rising temperatures reduced total global wheat production by 5.5 percent. According to a study published by the U.S. National Academy of Sciences, every 1.8 degree Fahrenheit rise in average temperature will reduce the global yields of wheat, rice and corn by an additional 10 percent. Some regions will be affected more severely than others. Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change (IPCC), projects that as early as 2020 grain yields in some African countries could be reduced by as much as 50 percent.

Water. Around the world, sources of the fresh water necessary for life are diminishing. Last May, a working group commissioned by the Pontifical Academy of Sciences published a report on the retreat of the world’s mountain glaciers. The water flowing gradually from these majestic ice formations sustains rivers that bring life to valley ecosystems and human communities. But the European Alps have already lost 50 percent of their glacial mass, and thousands of small glaciers in the Himalayan-Tibetan region are disintegrating. In Asia alone, over one billion people are in danger of losing their primary source of life-giving water.

Sea level rise. Melting glaciers and thermal expansion of ocean waters are contributing to a sea level rise already documented by scientists. According to one estimate, over the course of this century we can expect a rise of 3 to 6 feet. At just three feet, 50 percent of the rice fields in Bangladesh would be submerged. Portions of major coastal cities including New Orleans, Tampa and Miami would be inundated.

Ocean decline. The oceans absorb more than 25 percent of the carbon we emit through the combustion of fossil fuels—and in so doing they become more acidic. This is contributing to the decline of the coral reefs that provide habitat for a diverse array of exquisite sea creatures, including fish that are a source of protein for nearly one billion people. The warming of ocean waters has also been linked to a decline in the population of phytoplankton. These microscopic creatures produce oxygen, remove carbon dioxide from the atmosphere and form the base of the entire marine food web that supports krill, whales and fish.

Extreme weather events. There has been a marked increase in floods, droughts and other extreme weather events related to climate change. MIT scientist Kerry Emanuel, for example, has correlated rising sea surface temperature with an increase in the intensity and duration of hurricanes. Heat is a form of energy, and the warming of ocean waters increases the energy convection of storm systems.

Mass extinctions. Species already suffering from habitat loss in a world dominated by humanity may not be able to adapt to a rapidly changing climate. A report published in Nature in 2004 concluded that a climate warming in the mid-range of current projections will by the year 2050 lead to the extinction of 15-37 percent of the species examined in the study. Biodiversity is essential to ecosystem resilience. Moreover, as Thomas Aquinas noted, the rich diversity of earthly creatures gives humanity a glimpse of the beauty and glory of God.

Tipping Toward Catastrophe

Those of us privileged to live in homes with central heating can quickly adjust our thermostat to raise or lower the temperature. One might imagine that at some future point, when global warming is more advanced, we can cease our greenhouse gas emissions and quickly return the planet to its prior state. The global climate, however, cannot be so easily moderated. The carbon dioxide we have already added to the atmosphere and oceans will impact the earth for at least 1,000 years. Moreover, the climate is not a simple mechanical system but a complex reality with many interlocking, non-linear relationships.

This complexity includes phenomena known by climate scientists as “positive- feedbacks”—processes that take a small change in temperature and amplify it with exponential effect. Consider, for example, the melting Arctic ice caps. These enormous white crests deflect solar radiation back into space, just as white clothing protects us from summer heat. As the ice caps melt dark sea water that absorbs solar warmth is exposed. This elevates the temperature of the ocean water, which increases the melting of the ice caps, which decreases the polar deflection of solar radiation, and on it goes.

This kind of feedback process is also evident in the decline of the world’s forests. Forests absorb carbon dioxide from the atmosphere and play an essential role in regulating global climate. Across the globe, forests are dying back. The underlying cause appears to be stress caused by rising temperatures and altered precipitation patterns. When trees die, they cease the photosynthesis that removes carbon from the atmosphere and as they decompose they release the carbon they have absorbed. This intensifies global warming, which increases the stress to forests, which kills more trees, which release more carbon, and so forth.

Thawing tundras are another example of “positive-feedback.” In Siberia, an enormous expanse of frozen tundra is beginning to thaw. The tundra holds an estimated 70 billion tons of carbon, much of which would be released as methane, a gas 25 times more powerful in its heat-trapping effect than carbon dioxide.

These positive-feedbacks are one reason that climate change is progressing more rapidly than projected by the Intergovernmental Panel on Climate Change. The rate of sea ice melt in the Arctic, for example, is thirty years ahead of a projection made by the IPCC in 2007. Using both current observable reality and data from paleoclimate studies, an international group of scientists has recommended carbon levels that could preserve a climate hospitable to life. Johan Rockström and coauthors conclude in “A Safe Operating Space for Humanity” that a safe level of atmospheric carbon dioxide is no more than 350 ppm.

Atmospheric carbon dioxide is already at 391 ppm and rising 2 ppm each year. If we are to have at least a fighting chance of returning carbon dioxide levels to 350 ppm, the global community must work with unprecedented cooperation to transform our sprawling fossil-fuel global economy to a network of efficient regional economies powered by non-carbon sources of energy. We must preserve surviving forests and replant denuded lands; replace agricultural practices that release methane and carbon into the atmosphere with practices that restore soils and sequester carbon; and intensify research and development of other means of removing carbon from the atmosphere.

The urgency of the transition to a new form of human civilization cannot be overstated. The warming generated by our own greenhouse gas emissions and accelerated by nonlinear feedback processes is pushing us ever closer to what scientists call “runaway climate change.” This ultimately could elevate atmospheric greenhouse gases to the level of the Cenozoic Era (65 million years B.C.) when the planet was ice-free and homo sapiens did not exist. “We are interfering,” concludes science writer Fred Pearce, “with the fundamental processes that make Earth habitable.” A 2007-08 UN Human Development Report concluded, “There is now overwhelming scientific evidence that the world is moving towards the point at which irreversible ecological catastrophe becomes unavoidable....There is a window of opportunity for avoiding the most damaging climate change impacts, but that window is closing.” 

Choose Life

Unlike abortion and the death penalty, climate change does not entail an intentional act that ends the life of another human being. It is the unintentional outcome of the industrial and agricultural processes that have accompanied our economic development. As early as 1979, however, scientists testified to Congress of the possible consequences of climate change, and our inaction is already taking the lives of vulnerable human beings. In 2009, a study conducted by the Global Humanitarian Forum found that climate change was already responsible for 300,000 deaths a year, the suffering of 325 million people, and economic losses of over $100 billion. Over 90 percent of those persons most severely affected were from developing countries that have contributed least to global carbon emissions. 

In the coming decades, climate change can bring deadly famine, displacement and disease to large sectors of the human population and spawn mass extinctions of other species. In the long term, the climate could change so radically that the earth could no longer support human civilization. In this sense, caring for the climate and the biosphere is a paramount pro-life issue.

Pope Benedict XVI lamented the failure of the international community to take appropriate action on climate change at the Copenhagen Climate Conference in 2009. The Vatican has installed solar panels on the roof of the Paul VI auditorium and declared the intention to make Vatican City the first carbon neutral state. In the United States, the Catholic Coalition on Climate Change supported by the bishops’ conference and other Catholic bodies is leading multiple initiatives, including the Catholic Climate Covenant. Participants in this covenant pledge in the spirit of St. Francis to educate themselves, pray, change their own energy-intensive patterns of living and lobby for policies that will address the climate crisis. These essential initiatives can be strengthened by recognizing climate change as a life issue that merits our attention in October’s annual Respect Life programs and January’s National Prayer Vigil for Life. We should also pursue new pro-life initiatives specific to the climate crisis, such as legal action to hold our government accountable for its repeated failure to protect the earth for generations unborn.

Our imperiled planet needs the distinctive paschal witness that the Catholic community can offer. At this time of ecological and economic crisis, Pope Benedict stated in a 2009 Easter address, "it is urgent to rediscover grounds for hope....Christ is looking for men and women who will help him to affirm his victory using his own weapons: the weapons of justice and truth, mercy, forgiveness and love."

Comments are automatically closed two weeks after an article's initial publication. See our comments policy for more.
12 years 6 months ago
Thank you for framing this as a life issue, for our climate is what enables us to live life more abundantly. 
Theo Verbeek
12 years 6 months ago
Please let us get our facts correct, rather than just accepting "computer driven predictions" as infallible truth. 
Many very doubtful statements in your otherwise interesting article. I just mention one: "treest don't die back in tropical heat". They flourished exuberantly on our earth when carbon dioxide was about 4000 ppm and the temperature about 40 degrees  Celcius (about 130F)! Those trees gave us an atmosphere with 20% oxygen. Sea level changes!? When the first wave of humanity reached Australia around 40 000 BC Tasmania was part of the mainland. When the second wave arrived 20 000 years later it was an island, the sea between the mainland and Tasmania has a depth of about 400 metres ! Climate change is part of our earth's history! Should we just happily keep burning our fossil fuels? That is a different question! We do need other energy sources! Windmills and solar panels will not provide that even if they are not to be neglected. Nuclear fission has its problems, but France has 70% from it and aircraft carriers and submarines are using it too.     
David Cruz-Uribe
12 years 6 months ago
Atmospheric concentrations of CO2 about 4000 ppm were recorded during the Eocene, which saw several periods of increased C02 concentrations and the associated global warming.  These events coincided with mass extinctions and other stresses that led to many changes in the flora and fauna. 

So yes, change has always been part of the climate, but the point is that humanity is now changing the climate at a rate that far outpaces natural phenomena.  Saying this is not the result of uncritically accepting computer models:  it is the conclusion of many different strands of evidence including careful comparisons between the model predictions and what is actually happening to the climate.  The Earth is getting warmer, sea ice is melting, glaciers are retreating.   There will be severe consequences for human civilization as food crops are disrupted by drought and increasing temperatures.
Colin Donovan
12 years 6 months ago
Man's activity surely has consequences on both micro and macro climates. However, is that really the big picture? In just a couple years we will know how active a solar maximum we will have this sun cycle. Given the decline in sun spots in recent years, some solar scietnists suggest we could be moving into an extended cool period, the last major one of which was called the little ice age. On geological time scales we are also overdue for a major ice age. All of which would make "global warming" irrelevant.
12 years 6 months ago
Could we please have an article giving the opposite point of view as well as this one. There are many respected scientists who would not agree with the above for very good reasons. They tend to be silenced. The America editors would surely want to open a debate for its readers by offering varying points of view - and not just in the letters section.
Craig McKee
12 years 6 months ago
This is a NO-BRAINER! We know that one hour of solar power provides all the energy consumed by the entire planet in one year, yet we are still messing around with fossil fuels. Corporate greed GENERATES political madness!
David Cruz-Uribe
12 years 6 months ago

Unfortunately, there is no real evidence that we are moving into a period of cooling because of the solar cycle.  This is an internet meme without scientific grounding:  please see

@Fr. Kilgannon

There are not "many respected scientists" who disagree with the essential conclusion that the Earth's climate is changing and the humanity is the primary cause.  97% of all climate scientists (i.e. those with the expertise to comment) believe this to be the case.  There is a very, very small handful of dissenters, but they have not been able to muster the evidence to convince their colleagues.   Thus, America Magazine has no grounds to present both sides of the debate.
Stanley Kopacz
12 years 6 months ago

Scientifically, there is only one side to this question.  The strength of CO2 as a climate driver is indisputible.  Look at Venus where tin melts on the surface.  There is no other side for the theory of how the the solar system is configured.  Perhaps America should waste its precious space and paper on flat earth nonsense, as well.  "The science isn't in". Climate change deniers live in a world where they misconstrue, exagerrate and misinterpret everything they can get their hands on to support their apriori belief that nothing is happening.

judi houchens
12 years 6 months ago
this is what the liberal wing of the Catholic Church is now trying to guilt us into believing?! I can't believe my church is buying into the "global warming"  now called "climate change" myth and even have a link for this article. I see that worship of a false God is in full force. 10 + yrs ago ted danson was spouting out how the sea levels are rising. Maybe that's the way God will have it end. Totally disgusted. It's like how they use "social justice" to scam people too.
Bryan Seigneur
12 years 6 months ago
@Theo Verbeek (2), I'm glad to see that you think fossil carbon should be reduced.  To the extent you believe that, you should encourage your local utility to move off of coal and gas.  You should also reduce your energy usage as much as possible while your utility is mainly coal.  You might also install solar.  If you produce enough solar, you might also replace one of your cars with an electric runabout.  Wow, this is getting complicated.

Or, we could all just impose a rising fee on fossil carbon, and the free market does everything for us.

This price should be imposed by the government, but it should be used to replace other govt revenue, not add to it (that is, lower taxes on work and investment!!!), or it should be returned to everyone in equal amounts.

The 'carbon cap' will be the average carbon usage per capita.  Those above the average will lose money, those below will make it.  The  average will fall with time as more industrious people rush to make the money being left on the table.

According to trade law, exports to non-carbon-tax nations could be subsidized (the money collected on their carbon energy would be returned) and imports from non-carbon-tax nations could be tariffed.  This is already being shown via the EU tax on airline carbon.   Other nations would have to impose their own equal carbon taxes in order to maintain equal footing.  This problem solves itself.  If we only quit denying it.  God helps those who help themselves.
judi houchens
12 years 6 months ago
@ stan kopacz: this just in.. thanks canada for doing the job american journalist refuse to do.


the shift shows how far humans are, even with supercomputers, from truly knowing what our weather will do in the long run" 

Hello.. God is calling. 

Stanley Kopacz
12 years 6 months ago
Judi Houchens, I read your site.  You are comparing apples and oranges. The prediction of short term weather patterns (meteorology) is not the same as long term changes in climate (climatology).  However, probabilistic computer models based on historical data will probably become less useful as the underlying conditions in the atmosphere change.  What was previously expected will no longer be valid.  Computer models help us to model complex phenomena.  I use computer programs to design and  predict the performance of complex optical systems.  If you know what you're doing, after we make the lenses and put them together in the fixturing, they work as predicted.  The climate models are more complex but they are constantly being worked on and improved by the climatologists, the great majority of whom consider global warming a fact.   I think you have a basic distrust of science and scientists along with a misunderstanding of what they do and how they work and what motivates them.  They are less concerned about what political fanatics think of them than looking stupid a hundred years from now by 22nd century scientists and stupid means doing dishonest science.
judi houchens
12 years 6 months ago

Stan, "Mr. Professor" as you so condescendingly sound in lecturing me about science. I work in the medical field and science is an integral part in our practice. I do know what meteorology and climatology are, but thanks for the review.
Money is a motivator of much. Environmental political fanatics are motivated by a myriad of things. Government subsidies, grant money, carbon credits which al gore and robt kennedy jr have made a bundle on.  Follow the money.   Alternate energy is the hope for the future, but until we get something that is equal (because nuclear won't happen), oil, natural gas, and coal rule. It's pretty obvious those scientists are not worried about looking "stupid" as you called it. There have been many "what scientist once thought" moments.
Science does start with hypothesis and The debates in theories are ongoing.

Stanley Kopacz
12 years 6 months ago
I lecture young engineers on physics and optics all the time, not in an academic setting.  You are welcome to my knowledge in physics and optics anytime.  In the meantime, I'm willing to listen to anything you have to say that might improve my health or about disease.  What I know doesn't allow me to indulge in climate change denying fantasies.

The latest from america

U.S. President Joe Biden, right, bends down to greet Pope Francis with their foreheads touching, ahead of a working session on Artificial Intelligence (AI), Energy, and Africa-Mediterranean, during the G7 summit at Borgo Egnazia, southern Italy, on June 14, 2024.
Pope Francis met with President Joe Biden and several other world leaders at the Group of Seven summit.
Pope Francis, seen from behind, sits at a working session during the G7 summit in Borgo Egnazia, Italy. The session discusses AI, Energy, Africa, and the Mideast. The background features a blue screen with the G7 Italia logo, and several attendees and photographers are visible.
The pope addressed leaders at the G7's special "outreach" session dedicated to artificial intelligence.
Pope Francis met with comedians to discuss the importance of humor, specifically as a tool for unity in the face of darkness and conflict.
“Sister Act” embodies the welcoming spirit of a church willing to go out into the street.
John DoughertyJune 14, 2024