Climate change

What is climate change?

Climate change refers to the increasing changes in the measures of climate over a long period of time – including temperature, precipitation and wind patterns. Climate change can be a natural shift, but since the 1800 humans have been the main cause. Using and burning gas, oil and coal releases a lot of Greenhouse gas. Greenhouse gas emission traps the heat of the sun in the atmosphere, raising the temperature on earth. Carbon dioxide and methane are the main gasses that have an influence on climate change. Climate change refers to changes in weather patterns and growing seasons around the world. It also refers to sea level rise caused by the expansion of warmer seas and melting ice sheets and glaciers.

Global warming

Global warming refers to the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere. Though this warming trend has been going on for a long time, its pace has significantly increased in the last hundred years due to the burning of fossil fuels. Global warming causes climate change.

What is precipitation in climate?

Precipitation is any liquid or frozen water that forms in the atmosphere and falls back to the Earth. It comes in many forms, like rain, sleet, and snow. Along with evaporation and condensation, precipitation is one of the three major parts of the global water cycle.

Wind patterns

Typically, climate change conversations focus more on temperature than wind patterns, but that could be changing. Per Energy Monitor, the August 2021 IPCC report argues that in most places, wind speeds will be drastically reduced as a result of climate change.

Global water cycle and its impact on climate change

The Atlantic Meridional Overturning Circulation also called AMOC, is an important part of the thermohaline circulation that plays an important role in regulating temperature on earth and for ecosystems. Because of climate change, the AMOC is slowing down resulting in not only local but also global impact.

What is Thermoline circulation?

Thermohaline circulation is a worldwide system of ocean currents. Thermohaline circulation consists of AMOC as well as the Gulfstream. The process depends on the amount of heat and the amount of salt in the water. When the water goes from the equator further up north or south. The water will evaporate because of the heat and the salt will be left behind in de rest of the seawater. Because the water is going further away from the equator the water will cool down. Saltwater is heavier than fresh water and cold water is also heavier than warm water. Therefore the salty and cold water will sink down to the bottom and travel all the way back to the equator where it will warm up very slowly and reach the surface. Then the whole proof of warming up and cooling down and sinking will happen again. This process can take more than a thousand years.

Thermohaline circulation is very important because it gives many countries a much milder climate than the countries would have had if there was no thermohaline circulation. For example, Europe is less cold because the air above the water gets warmer in the winter and therefore the wind and temperature are less cold in the winter and for example, the cooler water streams in the summer that flows back to the equator cool the countries that are close to the equator resulting in a less hot climate that it would be if there was no thermohaline circulation.

Global warming effect on the Thermaholine circulation

Because of global warming, a lot of sea and land ice is melting resulting in a relatively less salty sea. Because the sea is less salty the AMOC will slow down resulting in a global climate change. At the moment the AMOC is a lot slower than it used to be and the AMOC is also more unstable. This can result in a complete stop of the thermohaline circulation. When there is no thermohaline circulation Europa will become as cold as Canada on the same latitude and countries close and on the equator will become warmer. There also will become a change in wind direction because the high and low-pressure areas will be in different places because the warm water will not travel as far away from the equator. Normally a slowdown in ocean streams will result eventually in an ice age as it did in previous times while planet earth existed. It is also called negative feedback because warming the earth would result in melting sea ice which would result in a slowdown or stop of the thermohaline circulation and which would then eventually after a long period result in a cooling down of the temperature and resulting in an ice age. However, it looks simpler than it is and trying to turn the AMOC back around so we do not end up in an ice age takes thousands of years. The previous ice age period lasted for about 100.000 years.

However, the cooling down process that is essential is what we need to concur global warming and climate change is not as simple as it seems.

What would happen in the short term if the AMOC stops

What would really happen if the AMOC stops is not certain. Scientists are doing research but do not all agree on the possible and estimated consequences if there would be a stop in the thermohaline circulation. However, research has shown that without the thermohaline circulation, the North part of the northern hemisphere will cool down about 15 degrees in just a few decades. Patches of the Northern hemisphere would become drier however pather of the South hemisphere would become wetter. The atmospheric pressure would shift much higher above Europeasia. Trade winds from north to south will go further up south and get stronger. Wind from all over the world would intensify. Therefore the antarctic ice would even melt faster.

What is the effect of climate change on ENSO?

ENSO stands for El Nino Southern Oscillation and it is a cycle of warm (El Nino) and cold (La Nina) episodes that happen every few years in the pacific ocean. It is considered that El Nino and La Nina are the ocean effects of the atmospheric changes of southern oscillation. Though the process is local, ENSO has a global impact on the climate as well as the global economy Climate change disrupts weather patterns and the disruption of weather patterns will also affect El Nino and La Nina. Because of climate change El Nina and La Nina, events may increase in frequency and intensity. ENSO also impacts tropical cyclones and tropical pacific ocean storm activity and because of climate change, these will increase in frequency and intensity as well. La Nina and El Nino themselves are also good examples of the massive impact of changes in wind patterns.

Normal process of the ocean in the tropical pacific ocean

Strong trade winds blow westward across the tropical pacific ocean and push the warm surface water towards Australia and Asia. The sea surface is because of the trade winds half a meter higher and an average of 7 degrees celsius higher in the western tropical pacific ocean compared to the equator. Due to the trade winds blowing the warm surface water towards Australia and Asia, the cold water will warm up and rise to the surface on the west coast of South America. This process is called upwelling. Upwelling elevates cold, nutrient-rich water to the upper layer of the ocean. Nutrients like nitrates and phosphates are used by tiny organisms such as phytoplankton for photosynthesis, other organisms like clams eat the phytoplankton and other predators like fish or marine mammals eat the clams. The wind patterns are thus very important for the ecosystems. For many countries on the western side of South America have fishing as their primary industry Like Peru, Ecuador and Chile Because of the upwelling cold water the western side of South America is relatively dry and the warm surface water that gets pushed towards Australia and Asia contributes to more rainfall.

What is El Nino and what is La Nina?

• El Nino

El Nino is a process that happens irregularly at two to seven years intervals and it is not predictable or has a regular cycle like for instance ocean tides. Spanish called it Christ child because most of the time El Nino occurred around Christmas. Scientists discovered that El Nino occurs at the same time as the southern oscillation. El Nino events are defined by their wide range of teleconnections. Teleconnections are large-scale, long-lasting climate patterns that are related to each other and can have a global effect. When an El Nino effect happens the westward-blowing wind trade weakens along the equator. These changes in air pressure and wind speed cause warm surface water to move eastward and push the warm water to the coastline of South America. The upwelling process now happens on the side of Australia and Asia which results in extreme droughts in Asia and Australia and extreme rainfall in South America. Fish populations in de eastern part of the Tropical Pacific ocean. die or migrate due to the warm waters and lack of nutrients. EL Nino has had a devastating effect on the economy of South America and especially the countries where fishing is their primary industry. The warm water pushed coastal flooding and erosion. Flooding also limits transportation and destroys crops. This has a big impact on the global economy. In Asia and Australia, there are extreme droughts. The droughts threaten regions' water supply as reservoirs dry and rivers carry less water than usual. Agriculture that depends on water irrigation is threatened. STong el Nino events also have an impact on global atmospheric circulation. Global atmospheric circulation helps to distribute thermal energy. The eastward movement of atmospheric and oceanic heat causes unusually severe winters at higher altitudes in north and south America. Regions further north may experience longer and colder winters than usual.

• La Nina

La Nina is a reinforcing effect of what normally happens in the pacific ocean. The wind tide is even stronger than normal so there will be more warm water pushed to the coast of Australia and Asia and there is more upwelling cold water on the west coast of South America. The water temperature at the west coastline of South America is even lower and colder than normal resulting in extreme droughts in south America and extreme rainfall in Australia and Asia.

Climate change impact on animal welfare and wellbeing

Marine life

The global ocean is already experiencing the significant impact of climate change and its accompanying effects. They include air and water temperature warming, seasonal shifts in species, coral bleaching, sea level rise, coastal inundation, coastal erosion, harmful algal blooms, hypoxic (or dead) zones, new marine diseases, loss of marine mammals, changes in levels of precipitation, and fishery declines. In addition, we can expect more extreme weather events (droughts, floods, storms), which affect habitats and species alike.

Ocean acidification

The ocean and ocean life absorbs a large amount of the carbon dioxide that humans release in the air by burning fossil fuels. Because the ocean absorbs the carbon dioxide, the ocean becomes more acidic. Ocean acidification reduces the amount of carbonate, a key building block in seawater. This makes it more difficult for marine organisms, such as coral and some plankton, to form their shells and skeletons, and existing shells may begin to dissolve. The impacts of ocean acidification are not uniform across all species. Some algae and seagrass may benefit from higher CO2 concentrations in the ocean, as they may increase their photosynthetic and growth rates. However, a more acidic environment will harm other marine species such as molluscs, corals and some varieties of plankton (Figure 4). The shells and skeletons of these animals may become less dense or strong. In the case of coral reefs, this may make them more vulnerable to storm damage and slow the recovery rate. Declines in calcification because of the rising acidification of water due to absorbing the carbon dioxide emission (25%-30% of all CO2 emission)

• Ocean moves faster due to increased kinetic energy of ocean current due to the increased wind that is caused by the warmer temperatures due to the climate change.

Rising seawater temperatures

The rising seawater temperatures will cause mass mortalities, harmful algal blooms, decline in kelps beds (kelp is very important for absorbing CO2) and substantial changes in geographic distribution of species. Because the water becomes warmer due to the climate change, a lot of species are migrating further up north for the water to be cold enough to live in. The warm water habitats have increased, while cold water habitats have decreased. More than half of the world’s ocean surface temperature has consistently surpassed the historic extreme heat threshold. These extreme heat waves created by climate change threaten marine ecosystems and threaten their ability to provide resources for coastal communities. The marine heatwaves have affected critical foundation species like coral and seagrass, and the warming waters disrupts the ecological structure. * Shark species (and other species) have to migrate further up north because of the warming waters. Blue crabs are thriving in warm water and no longer have to burrow in the winter to survive, which changes the food chain and ecosystem. The food chain gets disrupted because marine life is shifting towards the poles to stay cool as water becomes warmer. Poleward and deeper distributional shifts. Climate change acts as an additional stress factor for species. Combined with other changes like in their food web, habitats and species distributions, the added stress of climate change and rising water temperatures cause a major shift in the ecosystem. The warming water creates problems for ecosystems and mating. Some species migrate during a season because of the water temperature (example: in the winter, they move south). These species meet their mating partners, or they became essential for the ecosystem. However, with the warmer seawater, these species do not have to move further south because the temperature is warm enough further up north. This can disrupt the ecosystems (in this case) in the souther part of the ocean. One of the main threat to marine biodiversity is habitat degradation due to climate change. The distribution of parasites and pathogens is directly correlated to temperature. The higher the temperature, the higher the transmission rate. Some evidence show the same correlation with virulence.

Hypoxia

What is Hypoxia: Hypoxia is water with low, depleted levels of oxygen. It is often associated with overgrowth of algae that leads to oxygen depletion. Hypoxia happens with water with high levels of nutrients, warmer water and other ecosystems disruptions due to climate change. Hypoxia is created mainly by agriculture nutrients and fertilizers that end up in the water due to rain, wind, storms or water dumping in the ocean from for example our sewage. The occurrence of dead zones is natural, but the occurring of dead zones are enhanced by humans. The warming waters are increasing the dead zones frequency and intensity, which leads to biological desserts in the ocean. The excess nutritions that run off into the water is the primary cause of the increasing of dead zones. Because of this nutrition pollution, Eutrophication happens, which has a negative impact on the aquatic ecosystems. The nutrition pollution fuels harmful algae blooms (HAM) and HAM can create toxins that when consumed by small fish work up the ladder of the food chain and can kill a lot of species, especially higher up the food chain. Beside the toxins, HAM also blocks sunlight, clog fish gills and create dead zones. Especially coastal regions, urban streams and rivers are common location for dead zones. The declining of oxygen in large parts of the ocean has biological and ecological consequences as well as local as globally. The warming water and nutrition pollution reduces growth, increased diseases, behavioural changes. Particularly for fin fish and crustaceans. Agrochemical use and other human activity's leads to rising levels of phosphorus and nitrogen.

Coral reefs

The coral reef is a very important part of the oceans ecosystems. Because of the rising temperatures of the ocean, the coral reef dies off slowly because of coral bleaching, coral diseases and mortality events due to the rising temperature. Research links high level of coral mortality with thermally stressed coral colonies. Global temperatures are rising and killing corals and decreasing populations connectivity. Coral connectivity is how individual coral and their genes are exchanged among geographically separated subpopulation, which can greatly affect the ability to recover from the climate change. The ability to recover is highly dependent on the connectivity of the reef. Declining of corals is due to climate change and the coral not getting enough time to recover between Bleaching events. Some coral species play a special role as reef builders, they are essential. Changes into the distribution of these essential reef builders due to climate change have big impact on the overall coral reef and the ecosystems. Because of the threat to coral reefs, some areas are protected: Marine protected areas. The main stressor of the coral reef is the rising water temperature, and reversing climate change is the only way to solve. Climate change boost the energy of cyclones and thus the disruption of the coral reef. The frequency will not necessarily increase, however the intensity will, and the post-cyclone recovery will be slower due to the destruction of the biodiversity by the cyclone and climate change. Restoring reefs to their past configuration is not an option any more. However, we need to do our best to keep the coral reef and stop further degradation. Unless rapid advances are made by 2040-2050, most warm water coral reefs are eliminated and communities that depend on coral reefs to survive are likely to face poverty, social disruption and regional insecurity. Coral reef does have the ability to adapt to the warming weather, but not as rapid as the climate is changing right now. The coral reef supports huge marine life systems as well as providing critical ecosystems service. Living without it is not an option and is going to be catastrophic for the biodiversity of this planet.

Arctic and Antarctic

The intensity of global water cycle has increased. This increase is likely to make dry areas even dryer and wet areas wetter, making the global climate more outbalanced. The global warming and thus warming waters have major consequences for the marine life living in the arctic or Antarctic. These consequences cause disruptions for the marine life such as: Tundra greening, increasing arctic river discharge, loss of sea ice volume, ocean noise, beaver range expansion, glacier permafrost hazards. Beside melting sea ice, the warming waters also decrease the amount of phytoplankton that many species and their food web depend on. Many species have a decreasing population because of the loss of the population of their food web due to the warming waters, which results in melting sea ice and the migration of species. The earth's sea level does not rise because of the melting sea ice. It only rises when the land ice melts. Although melting sea ice is still a big problem for the ecosystems, it is not a big threat to our rising sea level. Some species are migrating more northward, while other species stay in the same environment. This disrupts ecosystems and lifecycles, which has a big impact on all sea life. The kinetic energy of the sea is increasing as a result of the warming waters which impact the bottom suspension, mixing and erosion. Even the arctic waters and environment is showing high levels of toxic chemicals, with major consequences for the health of the environment and humans. The sea ice melts in the summer, but does not completely disappear. The sea ice grows back when it is winter again. The floating sea ice has been proved to influence on the polar environment, the ocean circulation, weather and the regional climate. When ice crystals are formed, the water under the ice becomes more salty. The waters with a high salinity becomes heavier and sinks to the bottom of the ocean. Once the water reaches the ocean floor, it slowly flows back to the equators to warm up.

Climate change impact on human welfare and wellbeing

• Ocean acidification: Ocean acidification has also an impact on human life beside the impact on marine life. It has a big impact on the food security and especially of Molluscs because they are more vulnerable to acidification. This could have a big impact on the economy as well. Also, the coast will get less protected because the marine life that is effected by the acidification also protect the coastal line. This protective function of reefs prevents loss of life, property damage, and erosion. Without this protection, it will cost us a lot more money, which is bad for the economy. Especially long term. It will also have a big impact on tourism that gets attracted by marine life and without the tourist the economy will suffer. There is a limit on how much carbon dioxide the ocean can absorb and the more acidic it becomes the less carbon dioxide the ocean can absorb.
• Extreme weather: The effects of more extreme weather and (tropical) storms will be huge and will occur more frequently. There will be a lot of damage on property's and coastlines, and it will affect human life and the economy.
• The rising sea level: The sea level is rising and flooding will occur more frequently which means a lot of people losing their homes or having a lot of damage on their property and coastline
• Vital fish species such as salmon are migrating to new territories, necessitating better international cooperation to prevent a conflict for when species migrate across the border of countries where the economy depends on fishing. It can have serious conflicts as consequence in different perspectives for human wellbeing: law, policy, economics, oceanography, and ecology.
• Fish have methyl mercury, which can lead to long term neurocognitive deficits in children that persist into adulthood. The methyl mercury has been increased due to increases in seawater temperatures.
• Intenser cyclones
• Coral reefs dies and communities that depend on coral reefs to survive are likely to face poverty, social disruption, and regional insecurity.

References

• EPA Climate change indicator: Precipitations

Sources

• UN about climate change
• National geographic about global warming
• climate about history of glacials and interglacials
• about interglacials an orbit
• causes and effects climate change
• Coast adapt about acidity of sea water
• The Ocean Foundation about ocean and climate change
• earth observatory about sea ice
• Wikipedia thermohaline circulatie
• Wikipedia AMOC
• The Guardian Golf stream collapse
• Gizmodo collapse Atlantic current
• The conversation about climate change and El Nino and La Nina
• Better Health about mercury in fish