Air Pollution: Carbon Emissions Explained

Carbon emissions air pollution refers to the release of pollutants into the air, specifically carbon dioxide (CO2) and other greenhouse gases into the atmosphere, primarily from the burning of fossil fuels. Since the Industrial Revolution, human activities have led to a significant increase in atmospheric CO2 concentrations, with annual emissions from fossil fuels rising from 11 billion tons of carbon dioxide in the 1960s to an estimated 36.6 billion tons in 2023. This has resulted in a global rise in temperatures and contributed to climate change. Carbon emissions air pollution has severe impacts on both human health and the planet, with indoor and outdoor air pollution causing nearly seven million deaths annually worldwide. It also affects weather patterns and ecosystems, threatening food security and public health. Reducing carbon emissions can help mitigate climate change and improve respiratory and cardiovascular health for populations in the long and short term.

Fossil fuels

According to the Intergovernmental Panel on Climate Change (IPCC), emissions from fossil fuels are the dominant cause of global warming. In 2018, 89% of global CO2 emissions were attributed to fossil fuels and industry. The burning of fossil fuels for energy production, transportation, and industrial processes are the primary sources of these emissions. For example, over 94% of the fuel used in transportation is derived from petroleum-based fossil fuels, resulting in significant direct emissions.

The impact of fossil fuel emissions on global warming is concerning. Carbon dioxide concentrations have risen due to the burning of fossil fuels, with annual emissions increasing every decade since the middle of the 20th century. In 2023, global carbon dioxide emissions from fossil fuels reached approximately 36.6 billion tons, according to the Global Carbon Budget. This impedes progress toward limiting global warming, as the continued rise in heat-trapping carbon dioxide contributes to soaring temperatures worldwide.

Additionally, the transportation sector, which heavily relies on fossil fuels, is the largest source of direct greenhouse gas emissions. The commercial and residential sectors also contribute to emissions by burning fossil fuels for heating and using gases for refrigeration and cooling.

To address the issue of carbon emissions from fossil fuels, a transition to renewable energy sources is necessary. The Paris Agreement, signed by world governments in 2015, demonstrates a commitment to reducing carbon emissions. However, recent reports indicate that more urgent action is required to meet the agreed-upon goals and limit global warming to 1.5°C above pre-industrial levels.

Climate change

Carbon emissions are a major driver of climate change. Carbon dioxide (CO2) is a greenhouse gas that traps heat in the atmosphere, and human activities—particularly the burning of fossil fuels like coal, oil, and natural gas—have significantly increased atmospheric CO2 concentrations since the Industrial Revolution. This has led to global warming and subsequent climate change, with far-reaching impacts on the planet and human health.

Sources of Carbon Emissions

Carbon emissions come from various human activities, with the burning of fossil fuels being a primary contributor. This includes the use of fossil fuels for energy production, industry, and transportation. For example, cars, trucks, ships, trains, and planes burn fossil fuels, releasing carbon emissions into the atmosphere. Additionally, the commercial and residential sectors contribute through the burning of fossil fuels for heat and the use of gases for refrigeration and cooling. Agriculture is another source, with livestock, agricultural soils, and rice production emitting greenhouse gases.

Impact on Climate Change

The increase in carbon emissions has led to a significant rise in atmospheric CO2 concentrations. Since the onset of the Industrial Revolution in the 18th century, human activities have raised atmospheric CO2 levels by 50%, resulting in a current concentration of 150% compared to 1750 levels. This has caused a corresponding increase in global temperatures, with average temperatures rising by over 0.8°C since the baseline period of 1961-1990. The link between CO2 concentrations and global temperatures has been consistent throughout Earth's history.

Impact on Human Health and the Environment

Mitigation Strategies

To mitigate climate change and reduce air pollution, policies and technologies that lower carbon emissions are crucial. This includes adopting affordable low-carbon technologies, transitioning to renewable energy sources, and implementing regulations to control harmful emissions. By reducing carbon emissions and air pollution, we can not only address climate change but also improve public health and environmental outcomes.

Health impacts

Carbon emissions are a major contributor to air pollution, which has severe impacts on human health. Air pollution is defined as the presence of contaminants in the atmosphere, such as dust, fumes, gas, or smoke, in quantities that can harm human health. While carbon dioxide (CO2) is not a traditional air pollutant, it plays a significant role in the greenhouse effect, contributing to climate change and indirectly impacting air pollution.

The primary sources of carbon dioxide emissions are the burning of fossil fuels, such as coal and oil, for energy and transportation. Deforestation is also a contributing factor. These activities release carbon that plants removed from the atmosphere through photosynthesis back into the air, disrupting the delicate balance of gases. As a result, carbon dioxide concentrations have been rising since the Industrial Revolution, and they currently account for about three-quarters of global greenhouse gas emissions.

The health impacts of carbon emissions and air pollution are far-reaching. Air pollution can affect almost every organ in the body, primarily through inhalation of pollutants into the respiratory tract. Fine particulate matter, such as black carbon, is of particular concern as it can penetrate deep into the lungs, enter the bloodstream, and travel to various organs, causing systemic damage to tissues and cells. This can lead to inflammation, oxidative stress, immunosuppression, and mutagenicity, impacting the lungs, heart, brain, and other organs.

The World Health Organization (WHO) has identified several major air pollutants, including particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants have been linked to respiratory and cardiovascular diseases, reproductive and central nervous system dysfunctions, and cancer. Children, the elderly, and pregnant women are especially susceptible to air pollution-related health issues. Maternal exposure to air pollution has been associated with adverse birth outcomes, such as low birth weight and pre-term births. Additionally, there is growing evidence suggesting a link between air pollution and diabetes and neurological development in children.

High levels of carbon dioxide exposure can also lead to a range of health issues, including headaches, dizziness, restlessness, difficulty breathing, sweating, tiredness, increased heart rate, elevated blood pressure, and in extreme cases, coma, asphyxia, and convulsions. Carbon dioxide emissions contribute to increased temperatures and humidity, which in turn facilitate the formation of smog, further exacerbating respiratory health issues.

Addressing carbon emissions and air pollution is crucial not only for mitigating climate change but also for improving public health. Implementing policies and interventions to reduce air pollution offers a "win-win" strategy for both health and the environment. This includes transitioning to sustainable power sources, improving energy efficiency, and reducing the burning of fossil fuels.

Greenhouse gases

The most abundant greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide (CO2), methane, nitrous oxide, and ozone. Human activities, particularly since the Industrial Revolution, have significantly increased the concentration of these gases, leading to global warming and climate change. The burning of fossil fuels, such as coal, oil, and natural gas, for energy, transportation, and industrial processes, is the primary contributor to the increased levels of greenhouse gases. Other sources include agriculture, waste management, and deforestation.

Carbon dioxide is the most significant driver of global warming, with human activities increasing its concentration in the atmosphere by over 50% since the Industrial Revolution. Methane levels have also risen by 150% during this period, and it is a more potent greenhouse gas than carbon dioxide, with 84 times the warming potential. Fluorinated gases, such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), are synthetic gases emitted from various household, commercial, and industrial applications. While present in smaller concentrations, they are highly effective at trapping heat and have a substantial impact on global warming.

The concentration of greenhouse gases is typically measured in parts per million (ppm), and these values have been continuously monitored since 1958 at the Mauna Loa Volcanic Observatory. Efforts to reduce greenhouse gas emissions focus on transitioning from fossil fuels to renewable energy sources, improving energy efficiency, and implementing measures to capture and store carbon dioxide. Additionally, reducing air pollution, particularly from particulate matter and short-lived climate pollutants like methane and black carbon, can have dual benefits for human health and the mitigation of climate change.

Carbon sinks

Carbon dioxide (CO2) is Earth's most important greenhouse gas. It absorbs and radiates heat, contributing to global warming and climate change. Carbon sinks are natural or artificial processes that absorb more carbon from the atmosphere than they release. They are an essential part of the carbon cycle, a process that has been balanced for thousands of years. However, human activities such as burning fossil fuels, deforestation, and industrial agriculture have disrupted this balance, leading to increased carbon dioxide concentrations in the atmosphere.

The ocean is the largest natural carbon sink on Earth. Phytoplankton, marine ecosystems, and biological pumps enable the ocean to absorb a significant amount of carbon dioxide. Coastal ecosystems, including mangroves, salt marshes, and seagrasses, are also important carbon sinks, known as blue carbon ecosystems.

Soils are another critical carbon sink and storage medium. However, intensive farming practices have depleted the organic carbon content in agricultural soils. Forests, with their abundance of plants and trees, are also significant carbon sinks, absorbing carbon dioxide through photosynthesis. Sustainable forest management, afforestation, and reforestation efforts are crucial for preserving and enhancing the carbon sink capacity of forests.

Artificial carbon sinks are human-made systems that store carbon in building materials or deep underground (geologic carbon sequestration). While artificial sinks have gained attention since the Kyoto Protocol of 1997, no major artificial systems currently remove carbon from the atmosphere on a large scale.

The preservation and enhancement of carbon sinks are vital for mitigating climate change. By maintaining and improving the carbon sequestration capacity of natural sinks, we can help reduce the amount of carbon dioxide in the atmosphere and work towards stabilizing our climate.

Frequently asked questions