Our Mother Earth
By Deacon Tom Cervone, Ph.D., Sister Maureen Houlihan, D.C., and Nicole Cervone-Gish, Ed. M.S.
Editor’s note: This series takes a deeper look at Pope Francis’ 2015 encyclical “On Care for Our Common Home, Laudato Si’.”
“Science tells us, every day with more precision, that it is necessary to act with urgency – if we want to have the hope of avoiding radical changes in the climate and catastrophes. We have just a few years – scientists calculate roughly fewer than 30 – to drastically reduce the emissions of gas and the greenhouse effect in the atmosphere.” (Pope Francis in TED talk: Earth cannot be squeezed ‘like an orange,’ Vatican City, 10/10/20).
Carbon dioxide is one greenhouse gas that requires capture from the atmosphere and storage in the ground or in plants. Scientists at the University of Southern Denmark reported the top five most efficient ecosystems for carbon storage are the tundra, seagrass, mangrove forests, salt marshes and tropical forests (Birgitte Svennevig, 10/29/18). The following descriptions give facts about these ecosystems.
The tundra is treeless and found in cold regions north of the Arctic Circle (arctic tundra), or above the timberline on high mountains (alpine tundra). Both make up about 13% of the Earth’s surface (Hu and Bliss. Encyclopedia Britannica, 3/12/22). With the tundra warming, its permafrost is thawing, which causes microbial activity to increase and emit more greenhouse gases. “A key to safeguarding Earth’s tundra habitats are cutting harmful, planet-warming pollution by switching away from fossil fuels” (Christina Nunez, Tundra Threats Explained, National Geographic Society, 6/12/19).
Seagrass thrives in underwater coastal zones. They are “under pressure, and actions are needed to preserve and reestablish them,” says professor Holmer from the University of Southern Denmark (Birgitte Svennevig, 10/29/18). Jayathilake and Costello (Biological Conservation, A modeled global distribution of the seagrass biome, 10/2018) mapped seagrass. It currently makes up less than 0.1% of the planet’s surface.
Mangrove forests grow at the edge of oceans and seas. They grow fast, store large amounts of carbon, act as barriers against erosion and provide wildlife habitat. Conservation International reported, “By protecting mangroves, we can help fight climate change －and protect the coastal communities most threatened by it. Even though mangrove forests make up 0.1% of the planet’s surface, they store 10 times more carbon than terrestrial forests.”
Salt marshes are found along the coast and help wildlife, ecosystems and economies (Binns and Gordon, The Pew Charitable Trusts, 3/1/21). With sea levels rising, what will happen to salt marshes? Matt Kirwan, a marine ecologist, in “Marshes on the move” (Gabriel Popkin, 6/17/21), believes coastal wetlands can outrun rising seas. Others are not so sure.
Tropical forests, sometimes called lungs of the planet, absorb much CO2 and increase local humidity. “They provide big climate benefits beyond carbon storage,” says Freda Kreier (Nature, 4/1/22). She found that tropical forests not only cool the planet by removing and storing CO2, but they also cool the planet by their ability to create clouds; humidify the air; and release cooling chemicals.
What can we do?
- Support efforts to protect and expand natural ecosystems that store CO2
In 2019, Iceland residents held the first funeral for a glacier. They… installed a plaque that read, “A letter to the future. Okjokull is the first Icelandic glacier ... In the next 200 years all our glaciers are expected to follow… This monument … acknowledges that we know what is happening and what needs to be done. Only you know if we did it. 8/2019. 415ppm CO2” (Under the Sky We Make, Kimberly Nicholas, PHD, 2021, page 81).
Dr. Tom Cervone is a deacon at Holy Redeemer Catholic Church in Evansville, Indiana with 50 years of experience in ecology. He graduated from St. Bonaventure University, a Franciscan University. Sister Maureen Houlihan, D.C. is a support sister on the Seton Harvest Farm started by the Daughters of Charity in response to the Communities - Care of Mother Earth. This CSA (Community Supported Agriculture) Farm grows all natural produce for shareholders and the poor. Nicole Cervone-Gish, Ed. MS. is an award winning ELL (English Language Learner) teacher, who lives in Evansville, Indiana with her family.