Ocean fertilization
Ocean fertilization is a geoengineering approach aimed at addressing climate change by enhancing the ocean's natural processes that sequester carbon. This method relies on the biological pump, a system in which carbon dioxide is absorbed by phytoplankton, the ocean's primary producers. By increasing phytoplankton growth through the addition of micronutrients, particularly iron, proponents believe that more carbon can be captured when these organisms die and sink to the ocean floor, effectively locking away carbon for millennia.
Though some scientists advocate for ocean fertilization as a necessary strategy to mitigate the effects of rising greenhouse gas levels, the practice has faced scrutiny and opposition from environmental groups. Critics express concerns over potential unintended consequences, such as disruptions to marine ecosystems and the risk of harmful algal blooms. Several experiments have been conducted, including a notable incident in 2012 involving iron sulfate in the Pacific Ocean, which drew significant criticism and regulatory investigation.
Legal and ethical considerations further complicate the implementation of ocean fertilization, as many regions have strict regulations against dumping foreign substances into marine environments. Recent research suggests that large-scale fertilization efforts may already be having negative impacts on fish populations, indicating the need for careful consideration of both benefits and risks associated with this geoengineering technique.
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Ocean fertilization
Ocean fertilization is a complex geoengineering project designed to combat the effects of global climate change. Geoengineering processes make significant modifications to Earth’s ecosystems in hopes of reducing the amount of greenhouse gases in the atmosphere. Some scientists argue that geoengineering will be necessary to fight global climate change, and that restricting the practices that led to an excess of greenhouse gases will not be enough to avert the catastrophic consequences of climate change.
Ocean fertilization uses the biological pump, a method by which carbon travels through the oceanic food chain, to trap carbon at the bottom of the ocean. This prevents carbon dioxide from returning to the atmosphere and accelerating global climate change. Scientists plan to dump large amounts of micronutrients onto the surface of the ocean, stimulating phytoplankton growth. This increases photosynthesis, removing carbon dioxide from the atmosphere. As the phytoplankton die and sink to the bottom of the ocean, the carbon they absorbed will remain trapped for millions of years.
Some large-scale ocean fertilization experiments have been attempted. However, they were sharply criticized by environmental activist organizations. Such organizations are concerned that dumping large quantities of nutrients into the ocean will have unintended consequences.
Background
Geoengineering is one method by which world leaders and scientists hope to combat global climate change. Global climate change is a process caused by the release of greenhouse gases into the atmosphere. Some greenhouse gases occur naturally within the environment. They trap heat on Earth, keeping the planet warm enough for life to exist. However, through many practices, humans have increased the amount of greenhouse gases in the atmosphere to dangerous levels. This is causing a disruption in the Earth’s natural heating and cooling process. On average, the Earth is reaching some of the highest temperatures in recorded history, resulting in widespread climate change.
Reducing the economic and environmental practices that have led to the development of global climate change may slow or stop its progress. However, scientists are developing new plans to rapidly reduce the amount of greenhouse gases present in the atmosphere. If successful, these plans could slow or even reverse some of the effects of global climate change. One such plan is known as geoengineering.
Geoengineering goes beyond stopping the harmful practices that have led to global climate change. It involves intentionally making large-scale changes to planetary environments designed to combat the effects of excess greenhouse gases. Scientists have proposed two different types of geoengineering solutions to climate change: reducing the amount of solar energy that reaches the Earth, and rapidly reducing the amount of greenhouse gases in the atmosphere.
Reducing the amount of solar energy that reaches Earth is sometimes considered the less practical of the two types of geoengineering. Despite this, scientists have devised numerous theoretical means of accomplishing that goal. Many of these plans, such as installing mirrors in space to reflect sunlight away from the Earth or the installation of massive pipes designed to bring nutrient-rich water from the bottom of the ocean to the surface, are currently beyond the means of world governments.
Overview
Ocean fertilization is a type of geoengineering designed to reduce the amount of greenhouse gases in the atmosphere by utilizing the oceanic food chain. It involves intentional manipulation of the biological pump, a complex natural system that already takes place in the world’s oceans. The biological pump is the means by which carbon travels through the oceanic food chain.
Primary producers, meaning organisms that live at the surface of the ocean, use sunlight for energy. They dissolve carbon dioxide, turning it into carbon. That carbon is converted back to carbon dioxide by other organisms that live deeper in the water. A small portion of that carbon is trapped at the bottom of the ocean, where it will remain for millions of years.
Proponents of ocean fertilization seek to exploit this process, hoping to rapidly accelerate it. This would lock a larger portion of the world’s carbon emissions beneath the ocean, allowing humanity to avoid dealing with the carbon for over a million years.
In order to stimulate this process, scientists would need to increase the rate of photosynthesis in the ocean. Scientists have proposed targeting low photosynthesis areas, then dumping large quantities of iron fillings and other nutrients into the seawater. This would stimulate the growth of phytoplankton populations, which will in turn lead to greater carbon dioxide absorption. Most of that carbon will be released back into the atmosphere through the biological pump. However, as some of those plankton die and sink to the bottom of the ocean, the carbon they absorb will become trapped.
Several environmental organizations have condemned the use of oceanic fertilization. They argued that dumping large quantities of foreign substances into the ocean might have unforeseen consequences. Some expected consequences include a sharp increase in phytoplankton numbers, increased numbers of fish, increased numbers of jellyfish, and large algae blooms.
Some oceanic fertilization experiments have been conducted. In 2012, the Haida Salmon Restoration Corporation dumped more than one hundred tons of iron sulphate into the Pacific Ocean to use ocean fertilization to boost salmon populations. However, the incident was sharply criticized by environmental groups and was later investigated by the Canadian government. Many members of the same group plan to perform a similar experiment off the coast of Chile. Unfortunately, the results of such experiments will only be apparent long-term.
One of the most difficult barriers for proponents of ocean fertilization to navigate is the legal framework surrounding the practice. In order to conduct experiments to test if ocean fertilization might make a notable difference in combating global climate change, organizations would have to continue to dump large quantities of fertilizer into the ocean. However, most coastal regions have strict laws forbidding dumping foreign materials into waterways. Even though oceans are suffering from overfishing and the effects of global climate change, many coastal governments are unwilling to risk the potential side effects of experimenting on their ecosystem. Research published in 2023 indicated that large-scale iron fertilization in the tropics caused a 5 percent decline in the biomass of fish and marine species. This percentage was in addition to the 15 percent decline expected from climate change. Warming temperatures deprive the surface of oceans of necessary nutrients.
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