Last week, Pope Francis officially released his encyclical, Laudato Si, which was his formal address of the threat of climate change. The pontiff also noted how our waterbodies are threatened, reported ThinkProgress.

Climate change and ocean conditions run nearly hand-and-hand. Because the planet’s average temperature is rising, our polar ice caps are melting. This melting negatively affects the habitats of polar animals like polar bears and penguins. ThinkProgress noted how melting will unlock carbon contained within the ice caps and contribute more to climate change.

“The melting in the polar ice caps and in high altitude plains can lead to the dangerous release of methane gas,” wrote the pope.

Melting polar ice caps also increase sea levels, a dangerous effect on aquatic ecosystems. Scientists believe sea levels will be six feet higher by the end of the century. Rising sea levels pose a risk to delicate coastal ecosystems, coastal infrastructures, and will cause billions of dollars in damage.

St. Augustine, Florida is already feeling the affects of rising sea levels, and the state could suffer $33 billion in damage by 2030.

Other than the damage inflicted by climate change, there’s the damage directly inflicted on the ocean’s by humans: ocean acidification, water pollution, and seafood overharvesting.

When carbon output is increased, the amount of carbon absorbed by the ocean is also increased. The spike in ocean carbon affects the development of shellfish like oysters and clams. The structural development of coral reefs is weakened due to overly-acidic ocean water.

According to the pope’s encyclical, “Carbon dioxide pollution increases the acidification of the oceans and compromises the marine food chain.”

The biggest threat of climate change and endangered oceans is the risk they pose to the world’s food supply. Similarly to how climate change can affect farming, endangered oceans can affect the world’s seafood supply.

The World Wildlife Foundation (WWF) estimated that three billion people eat seafood as their primary protein source. Acidic water, overfishing, and general pollution pose severe threats to that food supply. If damaged enough, there would be severe consequences on the planet’s human population, as some people could face certain starvation.

Pope Francis pleaded with everyone on Earth to treat climate change as the dangerous threat that it is. We only have one planet, but we are destroying it.