How Do Humans Throw Off The Carbon Cycle?

The carbon cycle is the process by which carbon moves through the earth’s various systems, including the atmosphere, oceans, ecosystems and geosphere. It is one of the most important cycles that make life on earth possible. The carbon cycle involves the exchange of carbon, in its various forms, between the atmosphere, oceans, vegetation, soils and geological deposits. The cycle maintains a balance of carbon in the atmosphere that helps regulate earth’s climate and allows life to thrive. Disruptions to this cycle, especially from human activities, can contribute to climate change and ecosystem damage.

Carbon cycles between the land, ocean and atmosphere in a number of different chemical forms. The most common form is carbon dioxide gas (CO2). Carbon dioxide exchanges naturally between the atmosphere and plants/soil through photosynthesis and cellular respiration. The oceans absorb large amounts of CO2 where it reacts to form carbonic acid. Carbon is also stored for long periods in fossil fuel deposits and sedimentary rock formations. A balanced carbon cycle, with equal rates of carbon emission and absorption, helps maintain stable climate conditions and ecosystems on which humans depend.

Human Impacts on the Carbon Cycle

Human activities have significantly disrupted the natural carbon cycle, mainly through the burning of fossil fuels like coal, oil, and gas. When fossil fuels are burned, carbon that has been stored underground for millions of years is released into the atmosphere. According to the IPCC, human activities release around 36 billion tons of CO2 into the atmosphere every year, which is about 100 times faster than natural processes.

Deforestation, particularly in the tropics, is another major contributor. Trees and plants absorb CO2 from the atmosphere during photosynthesis. When forests are cleared, burned, or otherwise removed, the stored carbon is released back into the air. Tropical deforestation accounts for about 20% of human-caused CO2 emissions.

Modern agricultural practices also emit significant amounts of greenhouse gases through activities like draining wetlands, applying nitrogen fertilizers, and raising livestock. The expansion of pastures and arable land at the expense of natural vegetation reduces the Earth’s capacity to absorb carbon.

In total, these human activities have increased atmospheric CO2 concentrations by over 40% since pre-industrial times. This has thrown off the natural balance of the carbon cycle, leading to rising global temperatures, ocean acidification, and other effects.

Fossil Fuel Emissions

Burning fossil fuels like coal, oil, and natural gas releases carbon dioxide (CO2) into the atmosphere. The process of extracting and burning fossil fuels emits billions of tons of CO2 every year. This makes fossil fuel combustion one of the largest contributors to the excess CO2 accumulating in the atmosphere.

Since the Industrial Revolution began in the mid-1800s, the burning of fossil fuels for energy production has skyrocketed. This has released ancient carbon stored underground back into the active carbon cycle. The rate of CO2 emissions from fossil fuel burning is estimated to be over 30 billion tons per year. This dwarfs the natural fluxes of CO2 between the atmosphere, oceans, soils, plants, and animals.

The release of CO2 from fossil fuel emissions has thrown off the natural carbon cycle that has kept Earth’s climate relatively stable for thousands of years. The excess CO2 acts as a greenhouse gas, trapping heat in the atmosphere and causing global temperatures to rise. This human-caused disruption of the carbon cycle is the major driver of climate change observed in modern times.


Trees and other plants absorb CO2 from the atmosphere through photosynthesis. This carbon is then stored within the plants and soil. When forests are cleared for timber or agriculture, this carbon storage capacity is lost. Deforestation is a major concern, as the world has lost over 40% of its forests in the last 300 years. The Amazon rainforest alone absorbs 2 billion tons of CO2 per year, which is essential for regulating the global carbon cycle. With high rates of deforestation continuing around the world, this critical carbon sink is diminishing. Tropical deforestation is estimated to contribute approximately 20% of greenhouse gas emissions driving climate change.

deforestation releases stored carbon back into the atmosphere


Agricultural activities such as tilling soil, applying fertilizers, and raising livestock release significant amounts of carbon into the atmosphere. Tilling exposes soil organic matter to oxygen, increasing microbial decomposition and CO2 emissions. The production and application of synthetic nitrogen fertilizers also generate greenhouse gases like nitrous oxide.

Livestock such as cattle, sheep, and goats produce methane as a byproduct of their digestive process. Manure decomposition further contributes to agricultural methane emissions. With increased demand for meat and dairy products, livestock production has grown rapidly in recent decades. The emissions from this sector represent 14.5% of total global greenhouse gas emissions.

Sustainable farming practices like no-till cultivation, organic fertilizers, and rotational grazing can help reduce carbon losses. But continuing population growth will require feeding more people, necessitating a reduction in food waste and changes in dietary patterns to lessen climate impacts.

Other Factors

In addition to fossil fuel emissions, deforestation, and agriculture, there are other human activities that contribute to disrupting the carbon cycle. Two significant examples are cement production and waste management.

The production of cement leads to carbon dioxide emissions in two ways. First, fossil fuels are burned to heat the kiln materials to very high temperatures. Second, the heating process chemically converts calcium carbonates in the raw materials into calcium oxide, releasing CO2 as a byproduct. Cement production accounts for around 5% of global carbon dioxide emissions from human activities.

Waste management, including landfills and waste incineration, also releases significant amounts of greenhouse gases. As organic waste like food scraps, paper, and yard waste decomposes in landfills, methane is produced. Landfills are one of the largest sources of human-caused methane emissions. Incinerating waste also produces greenhouse gas emissions, including carbon dioxide. Improving waste management practices through increased recycling, composting, and landfill gas capture can help reduce these emissions.

Effects on Climate

Unbalancing the natural carbon cycle is causing major effects on the Earth’s climate. The most significant impacts are:

  • Increased CO2 and Temperatures – Higher concentrations of carbon dioxide and other greenhouse gases are trapping more heat, causing average global temperatures to rise. The planet’s average surface temperature has increased by about 1.1°C since the late 19th century.
  • Sea Level Rise – Warmer oceans are expanding and melting land ice is flowing into the seas. Sea levels have risen over 20cm in the last century and the rate is accelerating.
  • Extreme Weather – Climate change is increasing the frequency and intensity of extreme weather events like heatwaves, droughts, floods and storms. These events can be devastating for communities.

If emissions continue unabated, scientists project even greater warming and climate impacts in the future. This underscores the urgent need to restore balance to the carbon cycle.

Mitigation Strategies

There are several ways humans can help mitigate the effects of our activities on the carbon cycle. Some of the most impactful strategies involve transitioning to renewable energy sources, reforesting depleted areas, and developing more sustainable agricultural practices.

Renewable energy sources like solar, wind, hydroelectric, geothermal, and biomass energy generate power without emitting greenhouse gases. Widespread adoption of renewable energy in place of fossil fuels could significantly reduce carbon dioxide emissions. Government incentives, investments in renewable technology, and consumer choices to purchase clean power can accelerate this transition.

Reforestation programs aim to rebuild depleted forest areas which act as natural carbon sinks. Initiatives to plant trees in deforested regions help remove carbon dioxide from the atmosphere. Protecting existing forests from clear-cutting also maintains their carbon absorption capacity. Engaging in reforestation efforts through donating, volunteering, or supporting sustainable forestry practices makes a difference.

Sustainable agriculture minimizes carbon outputs through altered tilling, fertilizing, irrigation, and livestock management practices. Reducing synthetic fertilizer usage, improving water management, using low-emission equipment, and optimizing animal feed all lower agriculture’s carbon footprint. Buying food grown using sustainable practices incentivizes farmers to adopt more carbon-friendly approaches.

Individual Actions

There are many steps individuals can take to reduce their carbon footprint and help mitigate climate change. Here are some of the most impactful actions:

Reduce, Reuse, Recycle

Reducing consumption, reusing products, and recycling materials decreases waste and energy use. Simple steps like using reusable shopping bags, drinking from reusable water bottles, composting food scraps, and donating or buying used goods make a difference.

Energy Efficiency

Improving home energy efficiency through actions like weatherstripping windows, installing LED light bulbs, regularly replacing HVAC filters, adding insulation, and purchasing ENERGY STAR certified appliances can significantly reduce energy use and utility bills.

Choosing energy efficient transportation like fuel efficient vehicles, carpooling, biking, walking, and public transportation over less efficient options lowers emissions.

Clean Energy

Opting for clean, renewable energy sources like solar or wind power for your home or business eliminates fossil fuel generated emissions. Supporting community clean energy programs helps grow renewable capacity.

Making sustainable food choices like consuming less meat and dairy, buying local and organic products, and reducing food waste also helps lower your carbon impact.


In conclusion, humans have made substantial impacts on the natural carbon cycle through activities like burning fossil fuels, deforestation, and industrialized agriculture. These have led to a major increase of CO2 and other greenhouse gases in the atmosphere. This greenhouse effect is causing global temperatures to rise at unprecedented rates, leading to disruptions in climate patterns, sea level rise, and more extreme weather. Stabilizing the carbon cycle is critical to mitigate these threats. Main strategies include transitioning to renewable energy sources, protecting forests and natural carbon sinks, improving agricultural practices, and reducing overall emissions. With global coordination and public action, it is possible to restore balance to the carbon cycle. But it will require significant changes in energy, transportation, infrastructure, and lifestyles. Urgent action is needed to avoid the most catastrophic climate change scenarios and impacts.

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