Corals reveal alarming changes unfolding along the Pacific coast – Earth.com

Report on Accelerated Ocean Acidification and its Implications for Sustainable Development Goals

1.0 Introduction and Executive Summary

• A new study reports that ocean acidity is increasing at a dangerous rate along North America’s west coast, particularly within the California Current and the Salish Sea.
• These findings indicate a significant challenge to achieving key Sustainable Development Goals (SDGs), primarily SDG 14 (Life Below Water) and SDG 13 (Climate Action).
• This report outlines the scientific evidence of accelerated chemical changes in coastal waters, the resulting threats to marine ecosystems and dependent human populations, and the urgent need for action aligned with global sustainability targets.

2.0 Scientific Findings: A Direct Challenge to SDG 14 (Life Below Water)

2.1 Accelerated Rate of Acidification

• Coastal waters are acidifying faster than the global ocean average, with seawater chemistry changing more rapidly than the atmosphere above it.
• Oceans absorb nearly one-third of anthropogenic carbon dioxide, but these coastal zones exhibit an amplified reaction due to a thermodynamic effect that reduces their buffering capacity against acidity.
• This directly undermines SDG Target 14.3, which calls to “minimize and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels.”

2.2 Historical Evidence from Coral Archives

1. Scientists used the orange cup coral (Balanophyllia elegans) as a natural archive to reconstruct a history of ocean chemistry.
2. A comparison of coral skeletons from 1888-1932 with samples from 2020 showed that seawater carbon dioxide rose by approximately 172 microatmospheres, while atmospheric CO2 increased by only 120 parts per million.
3. The most profound changes were recorded in deeper ocean layers (below 100 meters), where upwelled water now carries significantly more acidity, posing a greater threat to surface ecosystems.

3.0 Ecological and Socio-Economic Impacts

3.1 Threats to Marine Biodiversity and Ecosystem Health

• Rising acidity threatens the ability of marine organisms, such as crabs and other shelled creatures, to form and maintain their skeletons, jeopardizing the entire coastal food web.
• This degradation of marine habitats and loss of biodiversity is a direct contradiction to the objectives of SDG 14, which aims to conserve and sustainably use marine resources.

3.2 Implications for Coastal Economies and Livelihoods (SDG 8 & SDG 12)

• The Dungeness crab fishery, the most profitable in the Pacific, is at risk from slower growth and higher mortality rates in its early life stages due to worsening ocean conditions.
• The health of these ecosystems is intrinsically linked to the cultural, commercial, and recreational activities of coastal communities, impacting progress toward SDG 8 (Decent Work and Economic Growth) and SDG 12 (Responsible Consumption and Production).

4.0 Future Projections and the Imperative for Climate Action (SDG 13)

4.1 High-Emissions Scenario Projections

• Under a high-emissions scenario, models project that by 2100, acidity in the California Current could outpace atmospheric carbon increases by up to 60% at certain depths.
• This could cause pH levels to drop by 0.3, creating conditions where the minerals essential for shell-building organisms dissolve faster than they can be formed.
• The region serves as a crucial indicator, offering a “window into conditions predicted for the rest of the ocean in the coming decades.”

4.2 Recommendations for Mitigation and Adaptation

1. The study emphasizes that immediate and significant reductions in carbon emissions are essential to slow the pace of acidification, directly aligning with the goals of SDG 13 (Climate Action).
2. As major per capita emitters, nations have the capacity to alter these outcomes for the oceans.
3. Protecting and restoring coastal ecosystems can enhance resilience and provide marine life with more time to adapt to the changing chemistry.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The article primarily addresses issues related to two main Sustainable Development Goals:

• SDG 14: Life Below Water: This is the most central SDG, as the article’s core focus is on ocean acidification, its rapid progression in the California Current, and its detrimental effects on marine ecosystems, including corals and Dungeness crabs. The text explicitly discusses the changing chemistry of the ocean, the health of marine life, and the need to protect these ecosystems.
• SDG 13: Climate Action: The article clearly identifies the root cause of ocean acidification as the absorption of carbon dioxide from human emissions. It states, “Oceans absorb nearly a third of the carbon dioxide released into the air.” The call to action at the end, “Cutting emissions now can slow the pace of acidification,” directly links the problem and its solution to climate action.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the article’s discussion, several specific targets under SDG 13 and SDG 14 are relevant:

1. Target 14.3: Minimize and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels.
   • The entire article is a manifestation of this target. It presents a scientific study that measures, analyzes, and warns about the impacts of ocean acidification. The research itself, comparing historical and modern coral samples to understand changes in ocean chemistry, represents “enhanced scientific cooperation” aimed at addressing this specific issue.
2. Target 14.2: By 2020, sustainably manage and protect marine and coastal ecosystems to avoid significant adverse impacts…
   • The article highlights the threat to coastal ecosystems like the California Current and the Salish Sea. It warns that changes could “upend marine life” and that species vital to the coastal food web will struggle. The mention of protecting coastal ecosystems to “buy time for adaptation” directly aligns with this target’s goal of managing and protecting these environments.
3. Target 13.2: Integrate climate change measures into national policies, strategies and planning.
   • Although not explicitly mentioning policy, the article’s conclusion strongly implies the need for such measures. The statement, “As very large emitters per capita, we have the power to change our emissions and influence outcomes for the oceans,” is a direct call for actions that are typically implemented through national policies and strategies focused on emission reduction.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

Yes, the article mentions several specific scientific measurements and potential impacts that can serve as indicators for the identified targets.

• Indicator for Target 14.3 (Ocean Acidification):
  • Ocean pH levels: The article projects that “pH levels may drop by 0.3” by 2100 under high emissions scenarios. Measuring the average pH of seawater is a direct indicator of ocean acidity.
  • Seawater Carbon Dioxide Concentration: The study found that “seawater carbon dioxide rose by about 172 microatmospheres,” which is a quantifiable indicator of the chemical change in the ocean.
  • Aragonite saturation state: The article implies this indicator by stating that “the minerals that marine creatures need to build shells could dissolve faster than they can form.” The saturation state of minerals like aragonite is a key measure of the ocean’s corrosiveness to shelled organisms.
• Indicator for Target 14.2 (Ecosystem Health):
  • Health and mortality of key species: The article points to the potential for “slower growth and higher mortality” in the early life stages of Dungeness crab. Tracking the population health, growth rates, and survival of such keystone or commercially important species serves as an indicator of ecosystem health.
• Indicator for Target 13.2 (Climate Action):
  • Atmospheric Carbon Dioxide Concentration: The article uses the increase of “120 parts per million” in the atmosphere as a baseline to show that the ocean is acidifying even faster. The global atmospheric CO2 level is a primary indicator of progress on climate action.
  • Rate of Carbon Emissions: The call to “cut emissions” implies that the volume of CO2 and other greenhouse gases being emitted is the fundamental indicator that must be tracked and reduced to mitigate the problem.

SDGs, Targets, and Indicators Summary

Source: earth.com