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Geography

Sea Level Rise: The Looming Crisis

By Jonathan Bala May 24, 2024

Sea Level Rise: The Looming Crisis

Key Takeaways

Sea level rise is a consequence of climate change, driven by the melting of glaciers and polar ice sheets, and the thermal expansion of seawater. The global average sea level is projected to rise by nearly 1 foot by 2050 and potentially more than 3 feet by 2100. Coastal areas, particularly those in the United States, are already experiencing increased flooding, saltwater intrusion, and economic impacts due to rising seas. Strategies to adapt to sea level rise include building sea walls, elevating infrastructure, and implementing nature-based solutions. Policy solutions such as managed retreat, climate adaptation funding, and international cooperation are essential to mitigate and adapt to rising sea levels.

Summary

Global causes: Melting ice sheets, thermal expansion of seawater.
Local causes: Groundwater pumping, tectonic shifts, local geology.
Effects: Extreme weather, tidal flooding, land loss, economic impacts, saltwater intrusion, climate migration.
Responses: Property protection, infrastructure adaptations, nature-based solutions, policy interventions.
Future projections: 1 foot rise by 2050, over 3 feet by 2100, with higher scenarios predicting up to 6.6 feet by the end of the century.
Challenges: Economic costs, displacement of communities, contamination of freshwater resources.

What is Sea Level Rise?

Sea level rise refers to the increase in the total volume of ocean water, resulting primarily from the melting of glaciers and polar ice sheets and the thermal expansion of seawater as it warms. These changes are driven by climate change, which is caused by the burning of fossil fuels.

Types of Sea Level Rise

Global Mean Sea Level Rise: This is the global average sea level change relative to a fixed point, such as the center of the Earth. It reflects the overall increase in the volume of the ocean and is most directly linked to climate change.
Relative Sea Level Change: This measures the height of the ocean’s surface relative to a specific piece of land. It can be influenced by both rising water levels and changes in land elevation.

In 2022, U.S. agencies like NOAA projected several scenarios for future sea level rise, depending on greenhouse gas emissions. These scenarios predict a global mean sea level rise of almost 1 foot by 2050 and more than 3 feet by 2100 under intermediate scenarios. In high-emission scenarios, sea levels could rise by up to 6.6 feet by the end of the century.

Table 1: Projected Global Sea Level Rise Scenarios

Scenario	2050 Projection (Feet)	2100 Projection (Feet)
Low	0.6 – 1.2	1.6 – 3.3
Intermediate	0.9 – 1.8	2.3 – 4.9
High	1.2 – 2.0	3.3 – 6.6

Global Causes of Sea Level Rise

Melting Ice

Melting ice from glaciers and polar ice sheets is a significant contributor to sea level rise. For instance, the Greenland ice sheet loses about 270 billion tons of ice each year.

Thermal Expansion

As the oceans absorb heat from greenhouse gases, the water expands. This process, known as thermal expansion, has contributed to one-third of the global sea level rise since 2004.

Local Causes of Sea Level Rise

Local Geology

In some areas, geological factors cause land to sink, making the sea appear to rise faster. Norfolk, Virginia, is one such example, built on a slowly sinking impact crater.

Tectonic Shifts

Tectonic movements can also affect local sea levels. For example, parts of California are being pushed upward, masking the effects of sea level rise.

Groundwater Pumping

Extracting groundwater can cause land to settle, leading to a relative rise in sea levels. Jakarta, Indonesia, is sinking rapidly due to excessive groundwater pumping.

Effects of Sea Level Rise

Rising sea levels amplify the effects of extreme weather events. Higher baseline water levels mean that storm surges and flooding will be more severe.

Tidal Flooding

Coastal areas are experiencing more frequent high tide floods, known as “nuisance” or “sunny day” floods. NOAA projects that by 2050, the U.S. will see an average of 45 to 85 high tide flooding days per year.

Land Loss and Coastal Erosion

Rising seas will permanently submerge some areas of land and accelerate coastal erosion. By 2050, 4.4 million acres of U.S. properties could be below tide lines.

Economic Impacts

Sea level rise threatens costly infrastructure like sewage plants and power stations. The economic losses could reach trillions of dollars by 2100, with annual costs of $14 trillion from adaptation efforts alone.

Table 2: Economic Impacts of Sea Level Rise

Impact	Annual Cost (By 2100)
Property Loss	$500 million
Infrastructure Damage	$14 trillion
Energy Facilities	Nearly 300 at risk
Transportation	2,400 miles of roadway

Saltwater Intrusion and Freshwater Contamination

Saltwater intrusion from rising seas threatens freshwater sources and agricultural lands, particularly in coastal areas like Miami and Bangladesh. This contamination can lead to water insecurity and displacement.

Climate Migration

Rising sea levels will force populations to relocate, creating potential refugee crises. Up to 13 million people in the U.S. and millions more globally could be displaced by permanent inundation.

Concept image of a flooded Basilica San Giorgio Maggiore in Venice as sea level rise makes the city uninhabitable

Responses and Adaptations to Rising Sea Levels

Strategies for Property Owners

Flood Risk Assessment: Use flood maps to understand your risk.
Flood Insurance: Purchase insurance to protect against potential losses.
Home Elevation: Elevate homes and important possessions to avoid flood damage.
Relocation: Consider moving to safer, higher ground.

Strategies for Infrastructure

Sea Walls: Construct barriers to protect against flooding and storm surges.
Elevated Roads: Raise roads to prevent flooding.
Water Pumps: Install pumps to remove collected water.

Nature-Based Strategies

Preserving and restoring natural defenses like wetlands, dunes, and mangroves can reduce flood risks and provide additional benefits like recreation and food sources.

Policy Solutions

Engage at-risk communities in long-term planning to relocate infrastructure and homes to safer areas while bolstering resilience where necessary. Increase state and federal funding for climate adaptation projects, reform flood insurance programs, and protect critical infrastructure. International cooperation is essential. Major polluters must fulfill their commitments to reduce emissions, invest in clean energy, and support vulnerable nations through initiatives like the Green Climate Fund.

Conclusion

Sea level rise presents a significant challenge that requires immediate and sustained action. From understanding the science behind it to implementing practical and policy solutions, every effort counts. As the impacts of rising seas become more evident, it is crucial for governments, communities, and individuals to work together to mitigate risks and adapt to the changing climate.

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#ClimateChange, #SeaLevelRise, #GlobalWarming, #CoastalFlooding, #EnvironmentalImpact, #ClimateAction, #SustainableLiving, #AdaptationStrategies

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Earth Observation Satellites

Solutions for Microplastics: How Microplastics Hinder the Ocean’s Carbon Absorption and Worsen Climate Change

By Jonathan Bala May 21, 2024

Solutions for Microplastics: How Microplastics Hinder the Ocean’s Carbon Absorption and Worsen Climate Change

Key Takeaways

Microplastics are messing up the ocean’s ability to capture carbon, which is important for fighting climate change. Microplastics slow down the formation and sinking of marine snow, making the ocean less effective at removing carbon dioxide from the air. They also disrupt nutrient cycles, hurting the growth of tiny plants called phytoplankton that capture carbon. We need to act now and do more research to lessen the impact of microplastics on the ocean and climate change.

Summary

Impact of Microplastics on Marine Life and Climate: Microplastics pose threats to marine organisms and interfere with the ocean’s role in the carbon cycle.
Marine Snow and Carbon Sequestration: Microplastics increase the buoyancy of marine snow, slowing its descent and reducing carbon sequestration efficiency.
Experimental Findings: Studies show that microplastics slow the sinking of marine snow by about 20%, impacting carbon removal from the atmosphere.
Nutrient Cycling and Phytoplankton Growth: Microplastics release organic carbon upon exposure to sunlight, depriving phytoplankton of essential nutrients and impairing their growth.
Global Implications: The disruption caused by microplastics to marine processes could exacerbate global warming, highlighting the need for urgent action.
Research and Mitigation: Continued research is necessary to fully understand and combat the effects of microplastics on the ocean’s carbon cycle and climate.

Microplastics Testing

Main Article

Microplastics, tiny plastic particles less than 5 millimeters in diameter, have been identified as pervasive pollutants in marine environments. Their presence in the ocean poses significant threats not only to marine life but also to global climate processes. Recent research highlights the insidious impact of microplastics on the ocean’s capacity to absorb and sequester carbon, thus worsening climate change.

The Role of the Ocean in Carbon Sequestration

The ocean plays a crucial role in the Earth’s carbon cycle by acting as a major carbon sink. This process involves the formation of “marine snow,” which consists of dead phytoplankton and other organic matter that clump together and sink to the ocean depths, sequestering carbon away from the atmosphere. This natural mechanism helps regulate the Earth’s temperature by reducing the amount of carbon dioxide in the atmosphere.

Impact of Microplastics on Marine Snow

A recent study co-authored by researchers from Northeastern Universityand the University of New Hampshire reveals that microplastics are altering this critical process. Microplastics, due to their buoyant nature, increase the buoyancy of marine snow, slowing its descent to the ocean floor.

“Plastics want to float. If phytoplanktons grow on microplastics in biofilms, instead of as free-living organisms, that changes the buoyancy of the phytoplankton when they die,” explains lead researcher Aron Stubbins, a professor of marine and environmental sciences at Northeastern.

Experimental Observations

The research team conducted controlled experiments where they grew phytoplankton with and without microplastics. They observed the rate at which these clumps sank in cylinders filled with seawater. The experiments revealed that phytoplankton intertwined with microplastics sank approximately 20% slower than those without microplastics.

“Basically, the plastics are slowing down the sinking rate of the marine snow, which is potentially reducing the efficiency with which the ocean can remove carbon dioxide from the atmosphere,” says Stubbins.

Implications for Carbon Sequestration

The slower descent of marine snow has profound implications for carbon sequestration. As marine snow travels deeper into the ocean, it effectively transports carbon away from the atmosphere. The introduction of microplastics disrupts this process, potentially reducing the ocean’s ability to regulate the Earth’s temperature.

Nutrient Cycling and Phytoplankton Growth

Microplastics also impact nutrient cycling in the ocean. When exposed to sunlight, microplastics dissolve and release organic carbon that bacteria can utilize. This process robs vital nutrients such as nitrogen and phosphorus from phytoplankton, which are essential for their growth and carbon-capturing capabilities.

“The presence of microplastics in marine environments could significantly alter the nutrient dynamics and hinder the growth of phytoplankton,” notes co-author Jeffrey Krause, a marine scientist at the University of New Hampshire.

Global Implications and the Need for Action

The disruption of marine snow and nutrient cycling by microplastics poses a potential threat to global processes such as the carbon cycle. This could exacerbate climate change by reducing the ocean’s capacity to absorb and sequester carbon dioxide. As microplastic concentrations in the ocean continue to rise, their impact on these critical processes becomes increasingly concerning.

Urgent Need for Research and Reduction

Addressing the issue of microplastics in the ocean requires immediate action and continued research. Understanding the full impact of microplastics on the ocean’s carbon sequestration capabilities is crucial for developing effective mitigation strategies. Governments, industries, and communities must collaborate to reduce plastic pollution and protect marine environments.

“We’re finding that microplastics could be a threat to global-scale processes such as the carbon cycle that is so important for all life,” Stubbins emphasizes.

Tables

Table 1: Key Impacts of Microplastics on Marine Processes

Impact	Description
Disruption of Marine Snow	Microplastics increase buoyancy, slowing the descent of marine snow.
Reduced Carbon Sequestration	Slower marine snow descent reduces the ocean’s ability to sequester carbon.
Altered Nutrient Cycling	Microplastics release organic carbon, depriving phytoplankton of essential nutrients.
Impaired Phytoplankton Growth	Nutrient deprivation hinders the growth and carbon-capturing ability of phytoplankton.
Global Climate Impact	Reduced carbon sequestration exacerbates global warming and climate change.

Table 2: Potential Solutions to Mitigate Microplastic Pollution

Solution	Description
Reducing Plastic Production	Limiting the production of single-use plastics and promoting alternatives.
Improving Waste Management	Enhancing recycling and waste management systems to prevent plastic pollution.
Promoting Ocean Clean-Up Initiatives	Supporting efforts to remove existing plastic pollution from marine environments.
Advancing Research	Investing in research to understand the impact of microplastics and develop mitigation strategies.
Raising Public Awareness	Educating the public about the environmental impact of microplastics and encouraging responsible behavior.

Microplastics present a significant and growing threat to the ocean’s ability to absorb and sequester carbon, thereby worsening climate change. The disruption of marine snow and nutrient cycling by microplastics has profound implications for global climate processes. Immediate action and continued research are imperative to address and mitigate the impact of microplastics on the ocean and the Earth’s carbon cycle. By reducing plastic production, improving waste management, and promoting clean-up initiatives, we can work towards protecting our oceans and combating climate change.

Reference

The full study appeared in Marine Chemistry.
Microplastics Testing

Hashtags

#Microplastics, #OceanHealth, #ClimateChange, #CarbonSequestration, #MarineScience, #EnvironmentalImpact, #Sustainability, #PlasticPollution, #Research, #Conservation

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