More than 2,600 of the world’s top marine scientists warned last week that coral reefs around the world are in rapid decline due to human impacts. They urged immediate global action on climate change to save what remains.
The world’s largest society of reef scientists, the International Coral Reef Symposium (ICRS), met in the northeastern Australian city of Cairns, and warned that the livelihoods of millions of people were at risk. They pinpointed warming oceans, increasing ocean acidification, overfishing, and pollution as the principal causes of present and future reef mortality. Their Consensus Statement lays out a dark future for much of the earth and its creatures, unless the nations of the world act decisively.
|Healthy reef ecosystems foster amazing biodiversity|
Like so much of God’s creation, coral reefs provide unseen services to the earth and its creatures. They function as natural breakwaters for waves and storms, protecting coastal communities. They are crucial to global tourism. Their diverse creatures provide countless pharmaceutical benefits. And coral reefs provide food and livelihood for many millions of people.
“Worldwide, more than three billion people depend on marine and coastal biodiversity for their livelihoods,” said Jane Lubchenco, a marine scientist and head of the U.S. National Oceanic and Atmospheric Administration. “Marine fisheries directly or indirectly employ over 200 million people.” Corals act as the nursery for many fish species. No one is certain what would happen to global sea life without them.
But the world is already beginning to find out. The ICRS warned that 25-30% of the world’s reefs are already severely degraded. In the Caribbean, for example, 75-85% of the coral cover has been lost in the last 35 years. And the Great Barrier Reef off Australia has seen a 50 percent decline in the last 50 years, scientists say.
The ICRS Consensus Statement warned of much greater near-term losses: During this century, “CO2 emissions at the current rate will warm sea surface temperatures by at least 2-3 °C, raise sea-level by as much as 1.7 meters, reduce ocean pH from 8.1 to less than 7.9, and increase storm frequency and/or intensity.”
|One in four reefs are degraded, and many bleach and die|
They are describing a perfect storm for coral reef mortality: warmer ocean temperatures which cause corals to bleach and often die; ocean acidification from higher atmospheric CO2, which makes it difficult for corals to build their skeletal structures; and rising sea levels and stronger storms, driving increased sedimentation that chokes or buries reefs.
“This combined change in temperature and ocean chemistry,” says the ICRS, “has not occurred since the last reef crisis 55 million years ago.”
To make that clear, the world’s largest reef-science society is warning us that within 88 years, our actions will give rise to conditions not seen in 55 million years. And apparently, that was a bad time for reefs.
Jeremy Jackson, senior scientist at the Smithsonian Institution in the U.S. assures us that this isn’t alarmism. “What’s good for reefs is also critically important for people and we should wake up to that fact,” he said. “The future of coral reefs isn’t a marine version of tree-hugging but a central problem for humanity.”
For the most part, we are lay people, not research scientists. What should we make of these warnings from the scientists? The Christian Reformed Church (CRC) Creation Stewardship Report has some excellent guidance for us:
“Pay particular attention to consensus statements from scientific societies. It is true that scientists too are human; scientific conclusions may also contain error, exaggeration, or misstatement. As imperfect humans, this is unavoidable. Nevertheless, when a broad community of experienced and reliable experts, utilizing the checks and balances implicit in scientific review, agrees on consistent conclusions over a period of several decades, it is reasonable to accept these broadly based conclusions and plan for the future.” (CRC, p.39)
The Consensus Report on coral reefs would appear to be just the sort of broad agreement that the CRC has in mind. As partners by grace in God’s work of reconciling all things, we recognize that this includes his oceans and its innumerable creatures. But we now hear that our own activities are contributing to harmful conditions not seen on earth for millions of years.
What should we do? Again, we look to the CRC for help:
- Pray: Individually and communally, ask God for forgiveness for the sins of arrogance, pride, and greed that cause us to fail in our roles as stewards of creation, consume more than we need or ought, and ignore the plight of the poor and vulnerable.
- Increase awareness: Learn together what it would mean to act with justice and mercy among, with, and on behalf of those most affected by environmental degradation.
- Walk and talk: Personally and as a community, take an inventory of where we stand with respect to God’s creation, and brainstorm together where we will go from here. (CRC, p.57)
Let us add one further thought: Do it quickly! The passage of time does not favor God’s vulnerable reef creatures and the human communities that depend on them. In the words of ICRS head Terry Hughes: “There is a window of opportunity for the world to act on climate change, but it is closing rapidly.”
Thanks for reading.
Appendix: Consensus Statement on Climate Change and Coral Reefs
The international Coral Reef Science Community calls on all governments to ensure the future of coral reefs, through global action to reduce the emissions of carbon dioxide and other greenhouse gases, and via improved local protection of coral reefs.
Coral reefs are important ecosystems of ecological, economic and cultural value yet they are in decline worldwide due to human activities. Land-based sources of pollution, sedimentation, overfishing and climate change are the major threats, and all of them are expected to increase in severity.
Changes already observed over the last century:
- Approximately 25-30% of the world’s coral reefs are already severely degraded by local impacts from land and by over-harvesting.
- The surface of the world’s oceans has warmed by 0.7 °C, resulting in unprecedented coral bleaching and mortality events.
- The acidity of the ocean’s surface has increased due to increased atmospheric CO2.
- Sea-level has risen on average by 18cm.
By the end of this century:
- CO2 emissions at the current rate will warm sea surface temperatures by at least 2-3 °C, raise sea-level by as much as 1.7 meters, reduce ocean pH from 8.1 to less than 7.9, and increase storm frequency and/or intensity. This combined change in temperature and ocean chemistry has not occurred since the last reef crisis 55 million years ago.
Other stresses faced by corals and reefs:
- Coral reef death also occurs because of a set of local problems including excess sedimentation, pollution, habitat destruction, and overfishing.
- These problems reduce coral growth and vitality, making it more difficult for corals to survive climate changes.
Future impacts on coral reefs:
- Most corals will face water temperatures above their current tolerance.
- Most reefs will experience higher acidification, impairing calcification of corals and reef growth
- Rising sea levels will be accompanied by disruption of human communities, increased sedimentation impacts and increased levels of wave damage.
- Together, this combination of climate-related stressors represents an unprecedented challenge for the future of coral reefs and to the services they provide to people.
Across the globe, these problems cause a loss of reef resources of enormous economic and cultural value. A concerted effort to preserve reefs for the future demands action at global levels, but also will benefit hugely from continued local protection.