Scientific understanding of climate change has evolved overtime. What was originally understood to be primarily an atmospheric issue is now understood to be an ocean issue too.
The Ocean is Changing
Scientific understanding of climate change has evolved over time. What was originally understood to be primarily an atmospheric issue is now understood to be an ocean issue too. It is clear that the atmosphere and the ocean are continually exchanging heat, gases and liquids with each other and are therefore changing in relation with each other. The ocean has a heat absorption capacity of more than 1000 times compared to the atmosphere and has also absorbed up to 50% of total carbon dioxide emissions from the atmosphere. This absorptive capacity means that the ocean plays a major role in stabilising the effects of climate change. However, stabilisation comes at a high price for ocean health.
As surface temperatures and carbon dioxide levels increase, the chemical composition and structure of the ocean changes. Warm water is not as dense as cold water, so as the surface layer warms, it is less able to sink and circulate with the deeper, colder, layers of the ocean. There are also solubility effects, as oxygen dissolves more easily in cold water compared to warm water. Therefore, as the ocean warms, it is less able to absorb oxygen and circulate with cold water, which is creating the conditions for ocean deoxygenation and stratification, while compounding sea-warming. Increasing levels of carbon dioxide are making the ocean more acidic while lowering aragonite and calcite saturation which is necessary for the formation of bones and shells of various marine life. Melting glaciers are contributing to sea-level rise while reducing sun (and heat) reflecting spaces. These are just a few examples of the changes occurring between the ocean, atmosphere and cryosphere, which have further flow-on effects for marine life, such as shifting fish migration patterns and disrupting life cycle events of Arctic mammals.
Towards Integration of International Cooperation based on Science
Formal spaces for global cooperation on environmental issues have traditionally occurred in mandate-defined silos, operating to a large extent in isolation from one another. However, in the context of the current scientific understanding of climate change, it becomes clear that a fragmented approach will not solve the issue. The Dialogues brought together representatives from the United Nations Law of the Sea Convention (LOSC), the Convention on Biodiversity (CBD), the Food and Agriculture Organisation (FAO), among other relevant bodies, with an emphasis on the ocean and atmospheric integration. Furthermore, The Ocean Panel, an initiative of 14 world leaders to sustainably manage 100% of the ocean under their national jurisdictions by 2025, is another step in the right direction, particularly when it comes to addressing the impact of plastic pollution on the marine environment.
Warm Water Coral Reefs at Critically High Risk
One of the main findings from the IPCC concerned the outlook for coral reefs. Unfortunately, it is likely that 70-90% of coral reefs are at high risk of disappearing even in a "1.5ºC warmer world" scenario. This is an upgrade to the level of risk assigned to coral reefs compared to previous predictions by the IPCCC and highlights the need for immediate action. This finding is also consistent with the International Union for Conservation of Nature (IUCN) World Heritage Outlook 3 Report which identifies the world’s largest coral reef, the Great Barrier Reef in Australia, as having a “critical” outlook for the first time.
All Sustainable Development Goals Depend on a Healthy Ocean
The IPCC also highlighted how all Sustainable Development Goals (SDGs) are critically dependant on the health of the ocean: not just SDG14 - Life under Water. They emphasised urgent action as there are likely to be mostly negative impacts from climate change on SDGs in relation to losses in ocean ecosystem services. This analysis reinforces the message that a healthy ocean supports all life on earth. The ocean is certainly a life-support system for oxygen-dependent species, as 60-80% of all oxygen on earth comes from algae and bacteria living in the ocean.
The renewed focus and momentum of the Dialogues represents a major step forward in terms of international efforts embracing the reality that: ocean change is climate change. However, there is still a lot of work to do in terms of climate solidarity: with no clear global pathway forged that promises to deliver on, or below, a “1.5ºC warmer” world. The UN Secretary-General, António Guterres has since called for all countries to declare a State of Climate Emergency until carbon neutrality is reached. It is clear that COP26 needs to reach a radical peak in Climate Ambition to ensure a viable future for all.