Foundations

1.1 Climate Change

Climate change is a product of a long-term shift in temperatures and weather patterns. Human-induced activities such as burning fossil fuels (such as coal, oil and gas) have been the main driver of climate change, along with land-use changes (for example, deforestation). Burning fossil fuels and forests generates greenhouse gas emissions that act like a blanket wrapped around the Earth, trapping the sun’s heat, raising temperatures, and spurring global warming. Greenhouse gas emissions (from gasoline for driving a car or coal for heating a building) that cause climate change include carbon dioxide (CO₂) and methane (CH₄). Land and forest clearing releases carbon dioxide and eliminates the capacity of the forest to sequester CO₂; landfills for garbage are another significant source of methane emissions. Other gas emissions include energy, industry, transport, and agriculture.  Greenhouse gas concentrations continue to rise, and the Earth is now about 1.1°C warmer than it was in the late 1800s, with the last decade (2011-2020) being the warmest on record ². Climate change begins with temperature increases, triggering changes in several other areas, such as weather patterns, floods and cyclones. ³ The amount of carbon dioxide in the atmosphere is rapidly rising — now greater than at any time in the last 3.6 million years.⁴ Around 45% of the CO₂ emitted by humans remains in the atmosphere, a significant factor behind global warming.⁵

As summarized by the Intergovernmental Panel on Climate Change (IPCC) reports, many scientists and government reviewers agreed that limiting global temperature rise to no more than 1.5°C would help us avoid the worst climate impacts and maintain a liveable climate. Unfortunately, current policies in place point to a 2.8°C temperature rise by the end of the century.⁶ The emissions that cause climate change come from every part of the world and affect everyone. Therefore, everyone must take climate action. However, it is also critical to acknowledge the uneven nature of global carbon emissions – the 100 least-emitting countries generate only 3% of total emissions, while the ten countries with the most emissions from developed countries contribute 68%⁷,⁸

Test your knowledge!

1. What are the main human-induced activities that contribute to climate change? 
2. Describe two main greenhouse gasses.
3. How do greenhouse gas emissions impact the Earth's temperature?
4. What are some sources of methane emissions?
5. How have greenhouse gas concentrations and global temperatures changed over time? 
6. What is the recommended limit for global temperature rise according to the IPCC reports? 
7. What percentage of carbon emissions are generated by the 100 least-emitting countries? 
8. Which countries contribute the most to carbon emissions among developed countries? 

The consequences of climate change are undoubtedly impacting our planet through severe droughts, water scarcity, harsher wildfire seasons, rising sea levels, flooding, melting polar ice, catastrophic storms, ocean acidification, and a decline in biodiversity. The ocean bears a significant burden of these adverse effects, with pollution and marine litter also contributing to the declining health of our seas. Global assessments of UN Sustainable Development Goals (SDGs) show that the implementation of SDG 14, ‘life below water’, has made progress in recent decades, including the United Nations Decade of Ocean Science for Sustainable Development (2021-2030) declaration, which is a framework for diverse stakeholders to co-design and co-deliver solution-oriented research needed for a well-functioning ocean in support of the 2030 Agenda.

However, efforts to protect our ocean are still lacking overall. For example, fish stocks continue to decline due to unsustainable fisheries, the number of protected territorial marine areas is limited, and an estimated 8 million tons of plastic waste enters the ocean annually from land-based sources.⁹ Globally, we need to catch up in implementing Illegal, Unreported, and Unregulated (IUU) policies and regulations. Illegal fishing accounts for about 20% of the world's catch, costing up to $23.5 billion annually.¹⁰,¹¹ Despite the ocean covering 71% of the Earth’s surface¹², research and capacity-building funding within this field is minimal. Indeed, SDG 14 remains the least funded of all SDGs, receiving less than 1% of all philanthropic funding since 2009.¹³ Therefore, it is critical that we increase our collective knowledge about the threats our ocean faces and how we can better mitigate them.

To go deep…  

See more on SDG 14¹⁴

Ocean literacy is a broader expansion of the traditional notion of literacy based on seven fundamental principles: (1) Earth has one big ocean with many features; (2) The ocean and life in the ocean shape the features of Earth; (3) The ocean is a major influence on weather and climate; (4) The ocean makes Earth habitable; (5) The ocean supports a great diversity of life and ecosystems; (6) The ocean and humans are inextricably interconnected and, (7) The ocean is largely unexplored. For the purposes of this platform module, we will be focusing on principles 3, 5 and 6.

To go deep…  

See more on the Ocean Literacy Principles¹⁵

Ocean life ranges in size from the tiniest microbes to the largest animal on Earth, the blue whale. Most organisms and biomass in the ocean are microbes, the basis of all ocean food webs. Microbes are the most important primary producers in the ocean. They have fast growth rates and life cycles and produce a considerable amount of carbon and oxygen on Earth. Ocean biology provides many unique examples of life cycles, adaptations, and unique relationships among organisms (symbiosis, predator-prey dynamics, and energy transfer) that do not occur on land. The vast ocean is home to diverse ecosystems from the surface to the water column and below the seafloor. Ocean life is not evenly distributed through time or space due to differences in abiotic factors such as oxygen, salinity, temperature, pH, light, nutrients, pressure, substrate, and circulation. A few areas of the ocean support the most abundant life on Earth. Estuaries, for example, provide essential and productive nursery areas for many marine and aquatic species. So far, scientists have identified and recorded approximately 226,000 marine species, but it is possible at least one million organisms could inhabit the ocean.¹⁶

To go deep…  

What fascinating marine life inhabits the mysterious deep sea? Scroll to find out: https://neal.fun/deep-sea/

Ocean life ranges in size from the tiniest microbes to the largest animal on Earth, the blue whale. Most organisms and biomass in the ocean are microbes, the basis of all ocean food webs. Microbes are the most important primary producers in the ocean. They have fast growth rates and life cycles and produce a considerable amount of carbon and oxygen on Earth. Ocean biology provides many unique examples of life cycles, adaptations, and unique relationships among organisms (symbiosis, predator-prey dynamics, and energy transfer) that do not occur on land. The vast ocean is home to diverse ecosystems from the surface to the water column and below the seafloor. Ocean life is not evenly distributed through time or space due to differences in abiotic factors such as oxygen, salinity, temperature, pH, light, nutrients, pressure, substrate, and circulation. A few areas of the ocean support the most abundant life on Earth. Estuaries, for example, provide essential and productive nursery areas for many marine and aquatic species. So far, scientists have identified and recorded approximately 226,000 marine species, but it is possible at least one million organisms could inhabit the ocean.¹⁷

To go deep…  

What fascinating marine life inhabits the mysterious deep sea? Scroll to find out: https://neal.fun/deep-sea/

Humans have a complex relationship with the ocean as it affects all human life. It supplies freshwater and oxygen, moderates the climate, influences weather, and affects human health. The ocean provides food, medicines, minerals and energy resources. It supports jobs and national economies, serves as a highway for transporting goods and people, and plays a role in national security. The ocean is a source of recreation, discovery, and humankind's heritage. Laws, regulations, and resource management affect what is extracted and put into the ocean. However, human development and activity lead to pollution (point source, non-point source, and noise pollution), changes to ocean chemistry (ocean acidification), and physical modifications (changes to coastal area, continental shelf, deep ocean, and rivers). In addition, humans have removed most of the large vertebrates from the ocean and impacted many other marine and coastal fauna and flora. Much of the world’s population lives in coastal areas. Coastal regions are susceptible to natural hazards (tsunamis, hurricanes, cyclones, sea level change, and storm surges). The ocean sustains life on Earth, and humans must live in ways that sustain the ocean. Individual and collective actions are needed to manage ocean resources for all effectively.

Test your knowledge:

1. What are some of the human activities that negatively impact the ocean?
2. Why is it important for humans to live in ways that sustain the ocean?

Carbon is a chemical element, the 15th most abundant on Earth, and can be found as part of organic or inorganic molecules. Carbon is the foundation of all life on Earth. Carbon helps regulate the Earth’s temperature, makes all life possible, is a crucial ingredient in the food that sustains us, and provides a significant energy source to fuel our global economy. As a regulating mechanism, the carbon cycle process is nature's way of continually recycling or reusing carbon atoms, which travel from the atmosphere into organisms on the Earth and then back into the atmosphere repeatedly. Since our planet and its atmosphere form a closed environment, the amount of carbon in this system does not change. Instead, it is chemically transferred from one compartment to another over time.

Most carbon is stored in rocks and sediments, while the rest is stored in the ocean, atmosphere, and living organisms, referred to as carbon reservoirs or sinks. Carbon is released back into the atmosphere mainly when we burn fossil fuels or through fire blazes, volcanic eruptions, and the degradation of organisms after their death.  In the case of the ocean, carbon is continually exchanged between the ocean’s surface waters and the atmosphere or is stored for long periods in the ocean depths and sediment of marine and coastal areas. The ocean and other large bodies of water are excellent absorbers of CO₂. They absorb approximately 25% of emitted CO₂ from the earth’s atmosphere.¹⁸  This carbon is mainly held in the upper layers of the oceans. Carbon sequestration by the ocean can prevent further carbon accumulation in the atmosphere, thus contributing to regulating the planet's climate. It can happen in two primary forms – biologically (i.e., in oceans, forests and soil) or geologically. Carbon sequestration is the capturing, removal and storage of carbon dioxide (CO₂) from the earth's atmosphere and its accumulation in terrestrial and marine ecosystems.

A carbon stock or pool is the quantity of carbon in a reservoir or system that can accumulate or release carbon. A carbon flux refers to the amount of carbon exchanged between carbon stocks over a specific time between land, oceans, the atmosphere, and living things. Ecosystems play a critical and irreplaceable role in cycling and storing carbon over short, medium and long timescales.  

In the atmosphere, carbon is stored in the form of carbon dioxide (CO₂), but in water, this carbon dioxide is dissolved and reacts with water to become carbonic acid (H₂CO₃). The hydrogen ions (H⁺) in carbonic acid make water acidic, lowering the pH.  As CO₂ levels increase around Earth's atmosphere, the amount of dissolved CO₂ in water also increases, which increases the amount of carbonic acid, therefore decreasing the pH, a phenomenon termed “ocean acidification”.  

Test your knowledge:  

1. What is the status or key findings of the Global Carbon Budget for the year 2022? 
2. Describe four main carbon pools. 

As raindrops fall through the air, CO₂ molecules interact, creating carbonic acid in the raindrops, which lowers the pH value.¹⁹ Acid rain affects soils, which kills trees and other vegetation as it leaches aluminium from the soil and removes essential nutrients and minerals, potentially also harmful to fauna. pH is an important parameter in water stability.²⁰

Henry’s Law of physics states that the amount of gas dissolved in water will be proportional to the amount of the same gas in the surrounding air outside the water to reach equilibrium. Because of increased anthropogenic levels of CO₂ in the atmosphere, more CO₂ is dissolved in the ocean. As seawater absorbs more CO₂, the pH decreases, and the ocean becomes more acidic, causing ocean acidification.  When CO₂ saturates water, it depletes calcium carbonate sources in water. As the ocean becomes more acidic, marine organisms such as molluscs and calcareous red algae are heavily impacted – they can begin to dissolve as there are fewer carbonate ions for calcifying organisms to maintain their shells, skeletons, and other calcium-based structures.²¹ The acidity of the oceans (i.e. the concentration of protons H⁺) has dramatically increased by ~30%, and if CO₂ is continuously emitted at the current rate, it is estimated that by 2100, the ocean’s acidity will increase by 150%, A pH decrease of 0.3.²²,²³

The ocean is home to many different reproductive processes, especially in marine vegetation within coastal zones. Coastal zones can begin up to 100 km inland and include ocean waters extending from the upper intertidal zone to 40 m deep. These areas where land meets sea are marked by the presence of marine and coastal vegetation, such as seagrasses, salt marshes, kelps, and mangroves – otherwise known as ‘blue forests’. While only occupying about 4% of the total land area and 11% of oceans, they are some of the planet’s most productive ecosystems.²⁴ These habitats are often also referred to as blue carbon ecosystems because they act as carbon sinks, similar to their terrestrial counterparts. Blue forests are meaningful in climate change mitigation by capturing and sequestering atmospheric carbon. Blue forest ecosystems also provide several other ecosystem services, such as providing nursery habitats, raw materials, coastal protection, enhancing water quality and sustainable livelihoods for communities. Unfortunately, over the last 20–50 years, 50% of salt marshes, 35% of mangroves, and 29% of seagrasses have been lost.²⁵²⁶ Kelp are also facing a global decline in abundance of 1.8% per year.²⁷

Test your knowledge:  

1. Give some examples of marine and coastal vegetation found in coastal zones.
2. Why are these coastal zones referred to as "blue forests"?
3. What role do blue forests play in climate change mitigation?
4. What has been the trend in the loss of salt marshes, mangroves, seagrasses, and kelps in recent decades?

In next module, we delve into the world of superheroes. Blue forests refer to vegetated coastal and marine habitats, including mangrove forests, seagrass meadows, kelp forests, and saltmarshes. These remarkable habitats are celebrated as climate superheroes due to their pivotal role in capturing and sequestering greenhouse gases, effectively countering the impacts of climate change. Join us on this exciting journey as we explore the power and significance of blue forests in preserving our planet. 

Are you curious? Follow along to Module 2...