What are greenhouse gas emissions and what impact do they have on climate change?

n this article, we explain what greenhouse gas emissions are, which gases they include and what causes them. We also show why it is important to reduce greenhouse gas emissions and how companies can help to reduce their emissions.

What are greenhouse gases?

Greenhouse gases (GHGs) are gases in the atmosphere that trap heat energy and reflect it back to the earth's surface in the form of infrared radiation. These gases are natural components of the earth's atmosphere and play an important role in regulating the earth's temperatures. However, due to human activities since the industrial revolution, there is an excessive concentration of greenhouse gases in the atmosphere, which has led to a rise in temperatures and a worsening of the climate crisis.

What are greenhouse gas emissions?

Greenhouse gas emissions refer to the release of greenhouse gases into the atmosphere through natural processes or human activities, such as the burning of fossil fuels.

What is the greenhouse effect?

The greenhouse effect is a natural phenomenon in which certain gases in the earth's atmosphere trap heat and reflect it back to the earth's surface. This keeps the earth habitable as temperatures are stabilized. Without the atmosphere, which contains greenhouse gases, the heat released would return to space and the temperature on earth would be much colder. The natural greenhouse effect maintains an average, comfortable temperature of 15 degrees Celsius on Earth.

The greenhouse effect and its impact on climate change

Since industrialization, human activities have led to an excessive release of greenhouse gases and thus to an increased greenhouse effect, which is considered the main cause of climate change. The global concentration of carbon dioxide has increased by almost 50 percent since the beginning of industrialization. In the previous 10,000 years, the concentration of carbon dioxide was almost constant.

The increased temperatures resulting from the man-made greenhouse effect have far-reaching consequences for the environment. These include the melting of the polar ice caps, rising sea levels, more frequent extreme weather events such as heat waves and hurricanes, as well as changes in ecosystems and habitats.

The most important greenhouse gases

• Carbon dioxide (CO₂): CO₂ is the best-known greenhouse gas. It is colorless, consists of one carbon atom and two oxygen atoms and is naturally present in our planet's atmosphere. Human activities such as the burning of fossil fuels like coal, oil and natural gas or deforestation have led to a sharp increase in CO₂ emissions into the atmosphere.
• Methane (CH4): Methane is the main component of natural gas and has a more direct and stronger impact on our climate than CO₂. It is a greenhouse gas that is produced during the production and transportation of hydrocarbons as well as during livestock farming and the decomposition of waste.
• Nitrous oxide (N2O): Nitrous oxide is produced by agricultural activities, particularly the use of fertilizers, and by combustion engines.
• Fluorinated gases: These gases are used in various industrial applications, such as air conditioning and refrigeration systems.

Why is it important to reduce greenhouse gas emissions?

Reducing greenhouse gas emissions is crucial to limiting the effects of climate change and ensuring the long-term viability of our planet. Only by reducing emissions can the global temperature be limited to two degrees. This goes hand in hand with preserving ecosystems, improving air quality and quality of life and reducing extreme weather events such as droughts, floods and storms.

What causes the most greenhouse gas emissions?

The main cause of most greenhouse gas emissions is the use of fossil fuels. This includes the burning of coal, oil and natural gas. The largest sources of greenhouse gas emissions are the following areas:

1. Energy production: The generation of energy from fossil fuels such as coal, oil and natural gas is one of the largest sources of greenhouse gas emissions worldwide. Greenhouse gas emissions from the energy industry in Germany amounted to 221 million tons of CO₂e in 2020.
2. Transport: Greenhouse gas emissions from the German transport sector amounted to 95 million tons of CO₂e in 2020. The transport sector contributes significantly to the release of greenhouse gases, particularly in road transport with petrol and diesel-powered vehicles and in aviation and shipping.
3. Industrial processes: Industry produces a variety of goods that often require energy-intensive processes. These processes lead to significant greenhouse gas emissions, including the release of CO₂ and other greenhouse gases. The share of emissions from industry was 178 million tons of CO₂e in Germany in 2020.
4. Land use changes: The conversion of natural habitats into agricultural land, deforestation and changes in land use patterns contribute to the release of CO₂ into the atmosphere.
5. Agriculture: Agriculture is an important source of greenhouse gas emissions, mainly through the release of methane (CH4) from livestock and agricultural activities and nitrous oxide (N2O) from the use of fertilizers. In 2020, this sector generated 58 million tons of CO₂e in Germany.
6. Waste management: The disposal and decomposition of waste, especially organic waste in landfills, generates methane emissions.

How can companies reduce their greenhouse gas emissions?

The economy is responsible for a large proportion of greenhouse gases and therefore plays a decisive role in reducing greenhouse gas emissions. By setting up holistic sustainability strategies and reducing internal emissions based on science, companies can be a great lever for positive change. Here are some ways in which company emissions can be reduced:

• Increase energy efficiency: Companies can improve their energy efficiency by introducing energy-efficient technologies and optimizing their production processes.
• Use renewable energies: The transition to renewable energy sources such as solar and wind energy can significantly reduce CO₂ emissions.
• Establish sustainable supply chains: Companies can review supply chains and ensure that suppliers also adhere to sustainable practices.
• Emissions reporting: The publication of emissions data and targets can create transparency and encourage companies to reduce their emissions.
• Promoting innovation: Research and development of new technologies and business models that are low in emissions are crucial.
• Offsetting: Companies can also invest in projects to offset CO₂ emissions, such as reforestation projects or CO₂ certificates.