Draft:The Human Effect on the Carbon Cycle

What is the Carbon Cycle?

The carbon cycle is the natural flow of the element carbon through the earth’s spheres in different forms.

There are six main processes in the carbon cycle:

• Photosynthesis,
  • In photosynthesis after the energy produced by the Sun makes it’s way to Earth it is consumed by primary producers such as plants.

• Respiration,
  • The opposite reaction of photosynthesis is respiration. This is the process of consuming in oxygen and then releasing Carbon Dioxide, whether this be through animals or humans.

• Exchange,
  • Exchange is another important process. It lets us know about the interaction between the carbon cycle and water. CO2 can dissolve into water and over time CO2 extracted from the atmosphere is dissolving into the oceans, making ocean slightly more acidic, because CO2 dissolved in water forms a weak acid.

• Sedimentation,
  • Another stage is sedimentation. Carbon will settle on the bottom of the ocean or a freshwater system, this helps to create sediments that are rich in carbon. This can be a long term of short term deposit or sink for carbon. This is then what forms the fossil fuels that we use in everyday life. The quality of fossil fuel among other factors then determine the length of time of the sedimentation.

• Extraction,
  • Extraction is the removal of fossil fuels—fossilized carbon (or organic carbon) buried before its complete decomposition—and bringing them back to the Earth’s surface. In a subsequent step, fossil fuel combustion occurs. This converts fossil fuels or plant matter into CO2 and ash, and in the process heat and energy are released.

• and Combustion.
  • Combustion is an abiotic process. Combustion has had a massive influence on the carbon cycle ever since the industrial revolution. Deforestation and subsequent combustion of harvested wood releases more carbon into the atmosphere and decreases the recapturing of CO2 by eliminating any photosynthesis that the harvested trees could have provided.

Human Impacts:

There are many impacts humans have on the carbon cycle, some causing the amount of carbon in the earth’s spheres to rise, these include:

• Burning fossil fuels,

• Changing land use,

• and Using limestone to make concrete

Due to this, the amount of carbon dioxide found in the atmosphere is rising rapidly. The ocean absorbs roughly a quarter of the carbon dioxide that is released from burning fossil fuels. This extra carbon dioxide is then lowering the ocean’s pH level, this is through a process called ocean acidification.

Humans also affect the carbon cycle by burning wood through deforestation. This releases the stored carbon into the atmosphere, where it then becomes a greenhouse gas.

Greenhouse Gas and Greenhouse Effect:

The greenhouse gases then cause the greenhouse effect and in turn the enhanced greenhouse effect.

The natural greenhouse effect is a cycle caused by gases naturally present in the atmosphere such ascarbon dioxide, methane, ozone, nitrous oxide, chlorofluorocarbons, and water vapor. These affect the way earth responds to the heat energy radiated by the sun. Basically;

• Sunlight passes through the atmosphere, and is absorbed by Earth’s surface.
  • This warms Earth’s surface, and then Earth radiates some of this energy back out into space. As it passes through the atmosphere, gases such as, carbon dioxide, methane, nitrous oxide, and water vapour absorb most of the energy.
• The energy is then re-emitted in all directions.
  • This means some energy exits into space, but less than what would have had the atmosphere and its greenhouse gases not been there. This results in some of the sun's energy becoming ‘trapped’, making the lower part of the atmosphere, and Earth, warmer than it would have been otherwise.

As this process is similar to how a greenhouse works it’s known as the greenhouse effect. The sun’s energy passes through the glass panes of the greenhouse, but due to the set up of the greenhouse not all of it gets out, making the inside of the greenhouse a warmer and therefore better hospitable environment for the plants inside.

How Human Effected the Greenhouse Effect:

The enhanced greenhouse effect is the disruption to Earth’s climate balance caused by the increased collection of greenhouse gases, leading to an increase in the global average surface temperatures.

Put simply, there is a disproportionate amount of greenhouse gases in the atmosphere causing too much of the sun’s energy to get trapped. Most commonly called global warming.

The main cause of enhanced greenhouse effect is human interference. This is mainly from burning or using things that produce the toxic gases, putting them into the atmosphere causing it to get clogged up and therefore heating the Earth. This has lasting effects on the environment such as:

• Changing our weather patterns,

• Causing sea level rise

• Ocean acidification.

• Heat related deaths,

• Health and disease,

• Loss of biodiversity,

• and many more issues that have yet to be discovered.

Heat Related deaths;

Heat-related deaths are related to heat exhaustion and heat stroke, which have increased with global warming.

• Heat-related mortality for people over 65 years of age increased by approximately 85% between 2000–2004 and 2017–2021.

• Between 2000–2019 studies show approximately 489 000 heat-related deaths occur each year, with 45% of these in Asia and 36% in Europe.

Diseases;

Diseases that spread by vector (malaria, dengue fever) have increased due to warmer temperatures allowing vectors and pathogens to survive.

One of the leading causes of weather related deaths is heat stress and can aggrivate underlying illnesses including;

• Cardiovascular disease,

• Diabetes,

• Asthma,

• as well as increasing the risk of accidents and transmission of some infectious diseases.

Hot temperatures increase the ozone concentration, this can sometimes damage people's lung tissue and cause difficulties for asthma patients and those with lung diseases.

Weather Changes;

As the extra carbon is being absorbed by the air and water Earth’s climate changes, and is impacting extreme weather across the planet. Due to this there are many weather activities are happening more intensely and frequently, such as;

• Record-breaking heat waves on land and in the ocean,

• Drenching rains,

• Severe floods,

• Years-long droughts,

• Extreme wildfires,

• and Widespread flooding during hurricanes

Ocean Acidification;

As temperatures rise, mass coral bleaching events are becoming more frequent. Additionally, carbon dioxide absorbed into the ocean from the atmosphere has already begun to reduce calcification rates in reef-building and reef-associated organisms by decreasing pH levels. This process is commonly referred to as ocean acidification.

Wildlife;

As the temperature rises the areas where certain species inhabit are becoming too hot for them forcing them to either adapt quickly to the ever rising temperature or move out of their habitat. Some species have already gone extinct due to the drastic change in their habitat, these include:

• Rodents - Little Swan Island hutia (Geocapromys thoracatus) due to storms

• Fish - Yarkon bream (Acanthobrama telavivensis), and Tristramella magdelainae due to drought

• Birds - Kāmaʻo (Myadestes myadestinus), and Laysan rail (Porzana palmeri) due to storms

How this affects the sea ice and ocean temperatures:

Due to the rising temperatures of the world from global warming the Antarctician ice sheets are melting quicker and flowing into the sea.

This affects many things not just in the icy area but also around the whole world, these impacts include:

• Rising temperature
  • Less ice means that less of the suns heat is being reflected. This leads to more drastic heatwaves around the world, as well as more extreme winters as the high-pressure wind that circles the Arctic region is destabilized by warmer air, it can dip south, bringing frigid cold with it.

• Food Availability
  • Due to the extreme weather conditions from the melted ice, it makes growing crop especially difficult. The dramatic heatwaves or harsh winters causing significant damage to crop.

• Coastal Regions
  • As the ice melts, it in turn rises the water level affecting the coastal communities living near water. This in turn makes their islands and such more susceptible to coastal flooding and storm surge, making dangerous weather events even more so.

• Fauna in Arctic areas
  • In the wake of the ice sheets melting the regional temperatures rise causing the spring ice-breaking is happening sooner than usual. This then means that most, if not all, of the Emperor Penguin (Aptenodytes forsteri) chicks have yet to develop their adult waterproof feathers or learnt to swim. This is detrimental to the Emperor penguin population as it means that many of the chicks do not survive their first spring resulting in not being able to reproduce.
  • Another animal affected by the ice sheets are Krill (Euphausiacea), the ice melting means that their breeding ground has severely depleted. This does not however just affect the krill population. Not only do they help manage carbon emissions but they are also a large source of food for other species. As their populations decrease it means that there is no longer the stability that the shrimp provided in regards to the carbon cycle but also many animals no longer have a main food source.

• Toxic Gases
  • When the ice melts the large store of methane and carbon are released into the atmosphere, increasing the rate of warming. This, in turn, causes more ice and permafrost to thaw or melt, releasing more methane, repeating the process again more drastically.