What Are the 5 Effects of Climate Change?

Human influence on Earth’s climate systems is now an established fact corroborated by observational records and climate models. The term “climate change” broadly refers to the long-term shifts in average temperatures and weather patterns that have been measured since the pre-industrial era. In essence, there are five symptoms associated with climate change: 1) increased surface temperatures, 2) rising sea levels, 3) melting ice sheets, 4) declining biodiversity, and 5) decreased agriculture production.

What Are the Effects of Rising Temperatures?

Rising surface, ocean, and atmospheric temperatures, also known as global warming, is perhaps the most influential symptom of climate change. As average daily temperatures gradually increase, there may be more incidents of heatwaves and droughts. Global warming also adds to the likelihood of wildfire occurrences. Evapotranspiration-the combination of water evaporation, soil moisture evaporation, and plant transpiration-rids soils and vegetation of their moisture. Dried-out plant matter acts as kindling during wildfires and enables the spread of flames.

Excess heat may also be hazardous to human health. People who are exposed to extreme heat can experience a range of conditions, including heat stroke, heat exhaustion, heat cramps, or heat rashes.

Why Is Sea Level Rise a Problem?

Sea level rise is related to the melting of land-ice and thermal expansion in seawater caused by heating oceans. The most affected communities are those along coasts. Coastal systems are more sensitive to rising seas because of their low elevation and proximity to large bodies of water. Erosion from intense wave action and flooding threatens coastal infrastructure more than that of high-elevation and inland territories. On top of that, coasts are highly vulnerable to extreme storms such as tropical cyclones. Coastal storms, including hurricanes and tropical storms, generate powerful ocean waves and harsh winds that indiscriminately damage property and claim lives.

How Does Melting Ice Sheets Affect the Environment?

Ice sheets are permanent masses of ice that cover vast amounts of land in Greenland and Antarctica. Under the influence of global warming, ice sheets melt more quickly. Water from melting land ice inevitably flows into seas and contributes to rising sea levels. In return, increasing amounts of melting sea ice loss reinforce global warming. This is because brightly colored snow and ice surfaces reflect sunlight back into space, whereas darkly colored sea water absorbs sunlight and heat energy. As ice sheets melt, Greenland and Antarctica will continue to heat up, and vice versa.

Permafrost (layers of subsurface soil, gravel, and sand that stay frozen year-round) stores plant material and keep them from decomposing as long as they remain frozen. Thawing these icy structures will allow the natural breakdown of plant materials to take place. When organic materials decompose, an array of greenhouse gases such as methane and carbon dioxide are released into the atmosphere and intensify global heating.

Biodiversity Loss Effects

A report published in 2021 by the Intergovernmental Panel on Climate Change (IPCC) and Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) drew a connection between climate change and biodiversity loss. According to the report, long-term climatological shifts have the potential to adversely alter a wide range of ecosystems.

For example, ocean acidification, which is driven by warming sea temperatures, can be harmful to species that form shells and skeletons from calcium and carbonate. When large amounts of atmospheric carbon dioxide are absorbed by seawater, the water’s pH is reduced and the amount of carbonate ions decreases. Ocean acidification can make shells and skeletons grow more slowly or dissolve more quickly, leaving species like scallops, corals, sea urchins, and clams more prone to impaired health.

How Does Climate Change Affect Agriculture?

The physical effects of climate change could influence agriculture production in a myriad of ways because crops depend on suitable environmental conditions to grow. Crop growth can be disturbed by shifts in air temperature or losses in soil biodiversity.

A 2017 study titled, “Temperature Increase Reduces Global Yields of Major Crops in Four Independent Estimates“, compiled results from four analytical methods (global grid-based models, local point-based models, statistical regressions, and field-warming experiments). They discovered that “without CO2 fertilization, effective adaptation, and genetic improvement, each degree-Celsius increase in global mean temperature would, on average, reduce global yields…”. Exposure to hotter temperatures may therefore contribute to abiotic stress for crops. Assuming that this is true, climate change will make food security threats more pronounced in the future.

How Is Plastic Affecting the Arctic?

ice in the Arctic ocean
Ice in the Arctic ocean

A new review article, “Plastic Pollution in the Arctic“, contends that high levels of plastic pollution (including microplastics) have infiltrated the Arctic and intensified climate change’s effects. Plastics from agriculture, hydrocarbon exploration, landfills, illegal dumping, industry, households, fisheries, offshore industry and other such sources are routinely carried to and within the Arctic by atmospheric and aquatic circulation systems. As plastics move through the Arctic, they gradually break down and release greenhouses gases, including methane and ethylene.

Is There Plastic In the Arctic?

Transported plastics from local and distant sources are broadly distributed throughout the Arctic. The United Nations estimates that approximately 150 million tons plastic debris may be scattered across the Arctic. Plastics are found on Arctic shores, in the water column, in sea ice and in the bodies of marine biota.

How Does Plastic Pollution Affect Marine Life?

Arctic wildlife are known to ingest, become entangled in or smothered by plastic debris. “Plastic Pollution in the Arctic” reports that Arctic species such as sculpin (Triglops nybelini), the northern fulmar (Fulmarus glacialis) and belugas (Delphinapterus leucas) have been found with plastic inside them. Plastic ingestion may even affect marine invertebrates like zooplankton in the east Canadian Arctic and the Fram Strait (a sea channel between Greenland and Svalbard). The review further reports that the organismal impacts of plastic infiltration to many endemic species remain largely unknown.

The Fundamental Links Between Climate Change and Marine Plastic Pollution In The Artic

Plastics drive climate change, in return, climate influences distribution of plastics. Also, both climate change and plastics have oil and gas origins. Plastics are derived from greenhouse gases (GHGs) and continue to release GHGs throughout their life cycles as they degrade. Plastics and microplastics are thus expected to increase ocean heat content (OHC). According to “Plastic pollution in the Arctic”, plastics could also promote glacial thawing by affecting their light absorbance, structure and rheological properties.

Circulation systems, including wind, ocean currents and freshwater river flows, continue to move plastics through Arctic ecosystems long after they are originally introduced. Physical impacts associated with climate change effect the concentrations and distribution of plastic in the Arctic. Sea level rise or higher poleward wind speeds from global warming could transport greater levels of plastic debris to Arctic ecosystems.

These interactions suggest that climate change and plastic pollution are mutually reinforcing. The Arctic may be more sensitive to the effects of ocean warming and plastic pollution than most environments because of its permafrost, snow and ice. Climate change strategies aimed at mitigating ocean warming, will have to account for the emissions from plastic sources as well.

Are Climate Change and Plastic Pollution Related?

Plastic pollution and climate change are the most influential stressors to marine environments globally. These stressors are simultaneously occurring and interactive. Marine plastic pollution is made up of the plastic products that have accumulated in the world’s seas. From production to end-of-life, plastic materials release potent greenhouse gases, like carbon dioxide (CO2), methane (CH4) and ethylene (C2H4). Greenhouse gases from plastic materials contribute to ocean heating and exacerbate climate change.

Climate change refers to long term shifts in a region’s temperature or weather patterns. Climate events, such as flooding and storms, impact the concentration of plastic’s global distributions. A 2022 review titled “The Fundamental Links Between Climate Change and Marine Plastic Pollution” assembles evidence that demonstrate the feedback loops between climate change and marine plastic pollution.

How Does Climate Change Affect Pollution?

Plastics (including microplastics) are transported from place to place by way of winds, water flow patterns, and storms. Wind and storms can influence the dispersal of plastics. The same is true of flooding events and rainfall patterns. Climate change is already beginning to increase the frequency and magnitude of extreme weather phenomena, and will likely continue to spread plastics into novel environments, where they may disrupt ecosystems and or release heat trapping gases.

How Plastics Contribute To Climate Change

The 2022 review has three categories for plastic’s climate change contribution: “1) plastic production, transport and use; 2) plastic disposal, mis-managed waste and degradation; and 3) bio-based plastics”. From the very beginning of their life-cycle, plastic and bioplastics are greenhouse gas sources. Making plastic requires extracting organic materials, such as crude oil or plant matter, which are burned to be refined and processed. The resulting plastic must too be heated for molding and manufacturing. After use, the plastic product may be recycled, become landfilled, be incinerated, or end up an environmental pollutant. In each case, the plastic will emit more CO2 as it degrades or is melted, according to a 2019 study referenced.

Greenhouse Gas Emissions From Plastic Production

Climate change influences the distribution of plastic waste; plastic has substantial greenhouse gas contributions, which enhance ocean heating and climate change. Put another way, changes in climate and climate-driven extreme weather events influence the spread of plastic across environments, from oceans, to freshwater systems, to terrestrial areas. But co-concurrently, plastic influences climate change by releasing emissions twofold throughout its life-cycle; production (including refining and manufacturing) and after-use life (including landfills, recycling, incineration and environmental waste).

The Environmental Impact of GMOs

An article made available in Science Direct, 2022, unpacks the potential benefits that genetically modified crops have for reducing greenhouse gas emissions. Authors of the document, Emma Kovak, DanBlaustein-Rejto and Matin Qaim, claim that “genetically modified (GM) crops can help reduce agricultural greenhouse gas (GHG) emissions. In addition to possible decreases in production emissions, GM yield gains also mitigate land-use change and related emissions”.

How Do GMOs Affect The Environment?

GM (genetically modified) crops are agriculture plants that have had stretches of DNA added, effectively modified or turned off within their genome to achieve desired traits. GM crops are commonly designed to be more resistant to insects and tolerant to herbicides. Modified crops can therefore lower the need for chemical pesticides, which are greenhouse gas contributors. Also, yield increases from GM crop use may prevent greenhouse gas emissions from the conversion of natural land (land that is uncultivated) to cropland. Land conversions promote greenhouse gas emissions through tilling and forest clearing.

GMO Climate Change Strategy

The article contrives a hypothetical scenario in which the European Union (EU) lifts its “quasi-ban” against widespread GM crop use. Authors of the article assume that yield increases from genetically modified crop adoption in the EU would offer benefits similar to those observed in other industrialized, temperate-zone countries that use modified crops. They further assume that enhanced crop production in the EU will bring about proportional decrease in agriculture production elsewhere. The latter of these assumptions is built on the belief that land will be spared (remain uncultivated) because the EU will be producing more crops domestically, consequently shrinking land conversion demands in outside territories.

Avoided emissions estimates from increased yield are intentionally underestimated in the article. Although authors state that “…higher GM crop adoption in the EU would likely also lead to higher [technology] adoption elsewhere”, their avoided emissions estimates do not account for the implementation of technology related to genetically modified crop use.

Avoided emissions estimates also do not account for the implementation of novel modified crops and traits. In other words, estimates are strictly based on well known genetically modified crops (soybean, cotton, canola, maize, and sugar beet) and the traits that they are designed with.

GMOs Reduce Carbon Emissions

Even though estimates are based on already-existing technology for modified crop application as well as already-existing modified plants and traits, it may be fair to assume that new technologies and new crops and traits would emerge from increased modified crop adoption in the European Union. Authors of the article assert that the EU can and should “increase agricultural productivity through embracing new crop technologies, thus contributing to global environmental benefits”.

GMO Benefits

Adopting genetically modified crops in places like Europe, which has higher wheat crop loss levels-caused by insects and pathogens-that the global average, may result in improved crop growth by making vegetation more resilient to environmental stressors, such as disease, insects and herbicide application. Increased vegetation is expected to lead to enhanced soil fertility and improve carbon absorption in soils and biomass. By boosting crop yields in areas that have not broadly accepted genetically modified vegetation, tilling and forest clearing-related emissions can be mitigated.

Can Plastic Pollution Cause Climate Change?

An interesting review titled, “The Fundamental Links Between Climate Change and Marine Plastic Pollution”, describes the interactive relationship between climate change and marine plastic pollution. The review’s authors claim that climate change and marine plastic pollution are linked in three ways: a) the production of plastic relies on fossil fuel extraction and is thus a greenhouse gas contributor b) climate and weather influence the distribution and spread of plastic pollution across environments c) marine ecosystems and species are presently vulnerable to both climate change and plastic pollution.

plastic bottle in water

Greenhouse Gas Emissions from Plastic Production

The rise in plastic demand is likely due to its reputation as an inexpensive and lightweight material that has a wide range of uses. Plastic is used for packaging, electronics, toys, utensils, safety gear and infrastructure. Even so, plastic drives greenhouse gas emissions throughout multiple stages of its so-called “lifecycle”, from extraction and refining to transportation, incineration and recycling.

As common plastics degrade, they continue to emit greenhouse gases like methane or ethylene, which intensify ocean warming. Bio-based plastics, plastics made from biomass, are no exception. While bio-based plastics do produce fewer greenhouse gases than conventional plastics, they still release heat trapping molecules during their lifecycles. Degrading plastic products fragment into microplastics and smaller constituents parts that can be toxic to humans and marine organisms.

How Does Plastic Move Around the World?

Climate inevitably influences the movement of plastics between environments. Plastics are circulated by the flow of water and wind. Extreme weather, like floods and windy storms, can move plastics from one system to another. Flooding riverine systems can transport plastics into the ocean; tropical storms from oceans can push plastics into onto terrestrial surfaces. Releasing plastic into the ocean or onto landfills is not the end of that plastic’s life cycle. Plastic and microplastics continue to impact the ecosystems long after they have been disposed of by humans.

How Does Plastic Affect Marine Ecosystems?

Climate change is altering the distribution of many species by subjecting them to novel thermal conditions. When marine habitats heat up, the species within them are usually forced to move to new regions to find more suitable temperatures. Heating oceans also contribute to hypoxic zone and coral bleaching. Plastic, on the other hand, can is ingested by marine species, which can low survival odds. In some cases, marine animals become entangled by plastic products or have their feeding pathways obstructed.

Plastic also potentially facilitates species migrations because plastic debris attracts encrusting organisms and microbial communities. Therefore both climate change and plastic pollution can contribute to species movement between ocean regions. Increased species mobility can bring about invasive species risks.

How Does Plastic In the Ocean Affect Climate Change?

Authors of the review, “The Fundamental Links Between Climate Change and Marine Plastic Pollution”, reason that climate change and plastic pollution are fundamentally linked to one another. Plastic production is heavily dependent on fossil fuel use and the release of greenhouse gases as it degrades in oceans, both of which enhance ocean heating and climate change. Plastic dispersal across environments influenced by climate change-driven extreme weather. Marine ecosystems and species are vulnerable to these threats.

How Has Climate Change Affected Yellowstone Amphibians?

A new study published in the science journal Ecology Indicators highlights how environmental changes in Yellowstone National Park are leading to habitat loss for some amphibian species. As Yellowstone continue to heat up and dry out under the influence of climate change, certain amphibians that move across the park are expected to experience loss of habitable zones. Authors of the study predict that continued climate change will “reduce snowpack, soil moisture, and forest cover” and diminish wetland habitats throughout Yellowstone National Park.

Will Amphibians Survive Climate Change?

Amphibians are ectothermic, meaning that they absorb heat from external sources in their environment to regulate their body temperatures. That being the case, hotter temperatures are potentially beneficial to amphibians in certain microclimates. Microclimates are small, restricted sections of an area that have different climatic states relative to the surrounding space. Warmer microclimates can help amphibians survive through the winter or forage for provisions during the day. However, warming temperatures that also drive dryer air and soils can limit amphibians’ ability to rehydrate while traveling cross stretches of land.

Amphibian hydroregulation is likewise dependent on factors in their environment, as they are unable to control water evaporation from their bodies. Amphibians require humidity and sufficient water availability to avoid dehydration. Terrestrial habitats that lack moist soils and forest cover from direct sun exposure can impede amphibians’ thermo-hydroregulation abilities.

How Has Climate Change Affected Yellowstone National Park Amphibians?

Researchers of the amphibian-Yellowstone study mechanistically modeled the movement of amphibians within the park for the years 2000, 2050 and 2090 to gauge the “costs” (disadvantages) to amphibians under the influence of climate change. Model simulations included data relating to Yellowstone’s vegetation, weather and details about animals’ morphology and physiology. Western Toads (Anaxyrus boreas) were used as the subject species for the model. Inferences were then made about other amphibians native to the park.

How Did Amphibians Adapt to Their Changing Environment?

The results were mixed across the three “test areas” which were modeled; in one of the test areas, physiological movement costs increased, decreased in the second and were mixed in the last. Authors of the study “predict that climate change will reduce the physiological costs for toads in some regions of YNP but increase them in others”. Snowpack loss and drying conditions throughout portions of Yellowstone may shrink wetlands, which could limit breeding sites for toads and make travel between breeding sites more costly. Other amphibian species are expect to experience worse consequences from warming and drying climates than toads. For example, Boreal Chorus Frogs (Pseudacris maculata), are less resistant to desiccation than toads because they are more dependent on wetlands.

Are Amphibians Sensitive to Climate Change?

Strictly speaking, warming conditions do not affect all amphibians in Yellowstone National Park the same. Variations in weather and vegetation cover brought on by climate change may make moving across the stretches of land that surround wetlands more costly for some amphibian species, particularly those less tolerant to dry habitats.

What Are Direct and Indirect Effects of Climate Change?

Freshwater systems provide usable water for technological development, agriculture and human consumption, while also serving as habitats for various aquatic species. Therefore, freshwater systems are of crucial economic and ecological value. A 2021 study titled, ” “The Importance of Indirect Effects of Climate Change Adaptations On Alpine and Pre-Alpine Freshwater Systems” asserts that human-made transformations in water hydrology and pollution from sewer outflows and agriculture chemicals are threats to freshwater systems. Properly accounting for the effects of climate change and anthropogenic influence on aquatic environments will hopefully improve climate change adaptation policies.

What Is Freshwater?

Rivers, reservoirs, and streams are examples of freshwaters systems. Freshwater is a subset of Earth’s water which is significantly less salty than marine waters (like seas and oceans). The United States Geological Survey, a branch dedicated to science within the United States Department of the Interior, defines freshwater as “water containing less than 1,000 milligrams per liter of dissolved solids, most often salt.” Though freshwater is renewed through the water cycle, it is a finite resource. If freshwater is used more quickly than it is naturally replenished, water security risks may be enhanced.

What Are Direct and Indirect Effects of Climate Change?

Authors of “The Importance of Indirect Effects of Climate Change Adaptations On Alpine and Pre-Alpine Freshwater Systems”, regard higher frequency of extreme meteorological events and increased temperatures as “direct effects” of climate change. These direct effects adversely influence the state and quality of aquatic regions. Direct effects also interact with human responses to climate change and produce “indirect effects”.

So-called indirect effects refer to human practices that are aimed at climate change mitigation. Indirect effects include land-use changes, alterations to freshwater systems and increasing irrigation practices. Authors suggest that “indirect effects may, at least in the short term, overrun the impact of direct climate change on water bodies.” Though all biomes are predicted to be impacted by climate change, freshwater systems in alpine and pre-alpine regions may be disproportionately at risk due to agriculture and hydropower plants.

Adapting Water Management to Climate Change

Freshwater use for the production of energy, also known as hydropower, is typically made possible by dams and in-stream structures. Hydropower infrastructure generates usable electricity for homes and businesses. Authors of the 2021 review article posit that hydropower is used as an alternative to nonrenewable energy resources. Hydropower production is therefore considered an adaptation strategy to climate change. Hydropower installations in freshwater networks can fragment or isolate certain species populations which are ill-adapted for the changes in water flow and perpetuate biodiversity loss. By modifying the hydrology of freshwater systems, water usage for energy production can compound the direct effects of climate change to aquatic flora and fauna.

How Does Agriculture Affect Climate Change?

Agriculture can be of detriment to freshwater systems as well, but in a much different way than hydropower plants. Climate change can intensify extreme weather event trends, such as floods, storms and droughts; these effects can drive diminished crop yields. In the interest of mitigating threats to crops brought on by climate change, agriculturalists may expand irrigation infrastructure or enhance fertilizer use. These adaptations can exacerbate the consequences which are already affecting crop growth cycles.

What Is the Impact of Climate Change On Water Resources?

Authors of the 2021 review claim that “rain-fed dairy farming is currently the most predominant form of agriculture, but in the future these grasslands may become more and more dependent on irrigation”. Redirecting water for irrigation use can potentially limit the quantity of water available in freshwater ecosystems. Variability in weather regimes may contribute to further dependence on water from irrigation (rather than from rainfall) in the future. Some of the responses that agriculturalists are expected to as a response to a changing climate pose risks to freshwater systems. Policy makers must account for indirect impacts to alleviate worsening the ecological status and water quality within aquatic environments.

Increasing Heat-Stress Inequality in a Warming Climate

Observed heatwave trends have been on the rise in the last four decades according to a research article published in January, 2022. The study titled, “Increasing Heat-Stress Inequality In A Warming Climate”, projects further intensification of extreme heat events in the future. Excess heat events like heatwaves are a symptom of increasing temperature averages across many regions of the globe. High temperatures are an immediate threat to human wellbeing as they may contribute to crop failure, worsened wildfires and or heat-related deaths, such as heat exhaustion and heat stroke.

How Is Heat Stress Related to Climate Change?

Researchers of the 2022 study assert that their “findings demonstrate continued increases in heatwave exposure inequality because of delays in adaptation capacity in the developing world, compounded by a higher emergence of warming in low-latitude areas where most of the low-income countries occur”. Societies in the lowest-income regions are projected to have greater difficulties adapting to the challenges posed by a warming climate.

thermometer on orange surface

How Does Climate Change Affect Heat Waves?

This study used heatwave data from the years 1980-2019, and modeled future temperatures for 2030-end of century. Heatwaves here are defined as “an event during which daily mean temperature exceeded the 97th percentile of local annual mean daily temperature in a reference period for at least three consecutive days”. Authors of the study claim that they are operating under the assumption that vulnerability to heatwave-related risks and degrees of suffering are determined by economic development status.

Thus, researchers split all regions of the world into four socioeconomic classes for income: lowest, lower-middle, upper-middle, and highest, (based on population-weighted per-capita gross domestic product in 2015). They were then able to create a spectrum for economic adaptive capacities. Adaptation capacities include cooling systems, electricity, early detection and warning systems and infrastructure.

As reported in the study, a 60% global increase in the total number of heatwave days were recorded over the past 40 years. Average yearly heatwave seasons were 75% longer during the 2010 years compared to those in the 1980s. Also, “the maximum decadal amplitude of shock heatwave was between 2.16 (Europe) and 3.27 (North America) °C higher in the 2010s as compared to the 1980s”. Although heatwaves intensified across all socioeconomic classes, the “low-income region” observed the rate of increase in heatwave season length yearly.

Which Place Is Most Affected by Climate Change?

In the 2010s, the “high-income region” experienced 30% fewer heatwave days. Sensitivity to heat waves is significantly determined by a society’s adaptation efforts. Regions with relatively low incomes will face greater challenges and vulnerability to heatwaves due to their lack of access to resources which enable adaptation across sectors. Inferior adaptation capacities may hinder or delay institutional heatwaves responses to heatwaves, making societies with lower scoring GDPs more susceptible to the impacts of rising temperature averages and excess heat.

Climate Change Impacts on Seabirds and Marine Mammals

A new review published in Ecology Letters, a peer-reviewed scientific journal, assessed seabird and marine mammals’ responses to climate change and climate variability. Researchers based their analysis on data from more than 480 preexisting studies and found that “the likelihood of concluding that climate change had an impact increased with study duration”.

In other words, detecting the influence of climate change on certain species requires long-term observations. Furthermore, the analysis posits that species which had more limited temperature tolerance ranges and relatively longer generation times were reported to be most affected by changes in climate. (Generation times are temporal intervals between the birth of an individual organism and the birth of its offspring).

Seabird species: Australian Pelican (Pelecanus conspicillatus)

How Does Climate Change Affect Marine Life?

From the 484 peer-reviewed studies that matched researcher’s inclusion criterion, 2,215 observations were compiled into a database and mapped. This includes 1,685 observations for seabirds and 530 observations for marine mammals. 54% of observations for seabirds were distributed towards northern hemisphere (39% of observations from temperate and polar regions). For marine mammals, 83% of observations were distributed toward the northern hemisphere (53% of observations from temperate and polar regions). For both seabirds and marine mammals, tropical and subtropical regions represented a mere 8% of total observations.

What Marine Life Is Most Affected by Climate Change?

Authors of the preexisting studies found 38% of total observations to be related to climate change, 49% were attributed to climate variability, and 13% were attributed to both. Reproductive success and adult survival were the most common response variables studied on both taxonomic groups (60% for seabirds and 34% for marine mammals). According to the new review, “a significant majority of observations concluded that climate change had an effect on both the seabird and marine mammal groups for all the response classes”. Response classes include demography, distribution, condition, phenology, behavior and diet.

How Does Climate Change Affect Marine Biodiversity?

The longer the duration of the original studies, the more likely authors were to infer that the observed changes in taxonomic groups were due to climate change rather than climate variability. 189 of the preexisting studies (669 observations) that demonstrated climate change effects had a time span above the estimated average threshold of 19 years. Generally, studies on marine mammals were able to demonstrate climate change responses based on shorter time scales (17± 5 years) versus seabirds (22 ± 3 years).

What Is Causing Ocean Warming?

If you want to measure the rate at which global temperatures are rising, then the world’s oceans are perhaps the best places to observe. This is not only due to the fact that Earth’s surface is more than 70% water-covered, but also because ocean water absorbs 90% or more of Earth’s excess heat. Heat energy captured by ocean water is known as “ocean heat content”, which stores that heat for indefinite periods of time.

Ocean Heat Content

Because ocean water soaks up high proportions of atmospheric heat, they are essential for regulating Earth’s climate. Most of the ocean heating is stored at depths between 0 – 700 meters. Air would warm more rapidly without the ocean’s immense heat trapping capacity. Consequently, heat content builds near oceanic surfaces as they take on increasing amounts of heat.

Average Global Temperature by Year

A new analysis authored by 23 researchers that was published in the journal Advances in Atmospheric Sciences uses data across seven ocean basins to assess world ocean warming trends. The study titled, “Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions”, finds that ocean waters have been monotonously increasing in temperature since the year 1958, and that the rate of change sharply quickened toward the end of the 1980s, with 2021 containing more heat energy than any other year on record since recordings began sixty years ago.

Was 2021 the Warmest Year On Record?

With this, 2021 beat the previous record set by 2020 as the year with the most heat energy in world oceans. The team used preexisting sets of data from various measurement devices in conjunction with climate model simulations to prove the accelerated rate of ocean warming in recent decades. It is then inferred that the relatively recent temperature spikes are mainly attributable to increased greenhouse gas concentrations brought on by human activity. The analysis asserts that “the increased concentrations of greenhouse gases in the atmosphere from human activities trap heat within the climate system and result in massive changes in the climate system”.

Table 1 from study: Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions

Is the Climate Rising?

The study lists 2018, 2017, 2019, 2020, and 2021 (in order from least hot to most hot) as the hottest five years of the global ocean since the year 1955. These 5 years, which are quite recent and in close proximity to one another. This suggests that mean temperatures are approaching new highs.