The Ocean Is Absorbing Our Heat—But at What Cost? The Truth About Sea Level Rise

The world's oceans are beyond doubt the natural safety net of the earth. Through their daily activity, they are taking up an immense amount of extra heat produced by humans, which keeps our planet from global warming any more than it is. Many regions of the globe would be in much hotter weather if the ocean did not have such a heat capacity.

Of course its service comes at the cost. The ocean takes up more than 90% of the extra heat that has been trapped in the Earth's climate system by the buildup of greenhouse gasses in the atmosphere. This pushes down the warming of the atmosphere, but it also contributes to ocean warming, an impact on marine life, and increased sea level rise. To address an important question — what is ocean conservation? — it's crucial that these changes are understood. Preserving marine species isn't just a matter of conserving marine species anymore, it's about preserving one of the planet's most important climate regulators.

Why Are the Oceans Getting Hotter?

The amount of greenhouse gases (GHGs), like carbon dioxide and methane, released into the atmosphere by human activities like burning fossil fuels, deforestation, and industrial processes increases over time. These gases retain heat which otherwise would be lost into space, leading to imbalance of energy.

The ocean is considered as a huge reservoir of heat. The heat capacity of water is much greater than that of air, enabling it to trap and store enormous quantities of the sun's heat energy. The ocean has taken up by far the bulk, since the 1970s, of this surplus heat, thereby helping keep the global air temperature in check. But the stored heat does not go away, and it stays in the ocean for decades or even centuries, continually influencing the climate of the Earth.

The Reality of Ocean Warming

Whilst warming of the oceans appears to be happening slowly, the effects are already apparent around the world.

Heatwaves in the ocean are increasing in number and severity, corals are beginning to experience unprecedented bleaching and many species are taking to cooler waters. The warmer waters in the oceans also affect climate change through an increase in evaporation, a greater severity of tropical cyclones, and changes in rainfall.

The ocean stores a long-term history of excess heat from the earth which are quite evident indicators of climate change, and scientists have come to understand that the temperature of the oceans is one such indicator. Ocean temperature growth is a landmark of the increasingly negative energy imbalance of the planet each year of record breaking temperatures.

The Growing Threat of Sea Level Rise

Sea level rise is one of the most prominent impacts of the warming of the oceans.

When seawater warms up, it expands (thermal expansion). Meanwhile, as the temperature goes up, glaciers and polar ice sheets melt quicker, contributing even more water to the oceans. Combined these two act in tandem to push sea levels globally up even more rapidly than they have been in the previous decades.

The effects of lost beaches are felt far and wide. Cities along the coast line are ever more vulnerable to flooding, storm surges are steadily more powerful, freshwater is mixed with seawater, and millions of people are exposed to a rising threat of flood damages from living close to coast lines.

Sea level rise is a past reality of many island states and low lying coastal communities.

How Ocean Ecosystems Are Being Affected

Stable environmental conditions are vital to all ecosystems in the oceans. Small rises in temperature can upset an established food web, which has taken thousands of years to develop.

One of the most environmentally fragile ecosystems is a coral reef. During hot water, corals release the algae that gives it nutrients, causing coral bleaching. With continued warming, the reefs can die, and a vast array of species, who depend on these reefs, will die also.

Ocean temperature shifts also decrease the availability of oxygen, alter migration patterns, impact breeding cycles and promote the spread of invasive species. The effects on kelp forests, seagrass meadows and polar ecosystems are both striking parallels and show the profound connections of the oceans.

Fishing industry, coastal economies, and tourism are some of the activities more influenced by the health of marine habitats in general as global changes occur in the oceans.

What Is Ocean Conservation?

With the severity of climate change reaching even the deepest waters, people today are asking, what is ocean conservation?

In short, the protection, restoration and sustainable management of ocean environments and the species that rely on them is ocean conservation. It should involve protecting corals, mangroves, seagrass beds, ocean-going areas, and deeper ocean ecosystems, as well as diminish anthropogenic impacts like pollution, overfishing and habitat destruction.

Clean oceans help to regulate the climate, too. Marine habitats, including mangroves, salt marshes, and seagrass are in place to sequester considerable carbon amounts, also known as “blue carbon”, which is tracked when sequestering carbon dioxide from the atmosphere and to the benefit of biodiversity.

Conserving marine systems therefore contributes to the benefit of people–in addition to wildlife–and that this ensures a greater global resilience against climate change.

Why Reducing Greenhouse Gases Remains Essential

Conservation can increase the resilience of marine ecosystems, but can't mitigate ocean warming without addressing other drivers of the warming.

The best solution in the long term is to decrease greenhouse gases being released into the atmosphere. The shift to renewable energy, energy efficiency gains, forest conservation, and decreased carbon emissions all slow the rate of accumulation of heat in the Earth's climate system.

Scientists stress the importance of each 0.1 of a degree. Reducing emissions will lower ocean heat, sea level rise, Marine Habitats will be healthier and more comfortable environments for adapting to changing conditions.

The Ocean Cannot Carry the Burden Forever

The ocean has mitigated nearly all the impact of climate change by buffering large amounts of excess heat. However, there are unintended consequences that come with this unseen service. As temperature rises, all ocean ecosystems are changing, sea level rise is higher, and marine biodiversity is under increased pressure around the globe.

Learning about ocean conservation? is about, is about learning about protecting the ocean to address climate change. All of these are important measures for protecting the planet's future, through conserving marine habitats, restoring coastal ecosystems and reducing greenhouse gas.

Decades of the Earth's excess heat have been stored in the oceans. But the next question is not how much more it could extract, it's how quickly it could make human life push it to its limits.