What Are Greenhouse Gases (GHGs), and How Do They Cause Climate Change?

By: Chermaine Yap

In recent years, greenhouse gases (GHGs) and their impact on climate change have become widely recognized. As these gases trap heat in the Earth’s atmosphere, they disrupt weather patterns and cause rising temperatures, fundamentally altering our environment.

What Are GHGs and the Greenhouse Effect?

Understanding GHGs and the greenhouse effect is crucial as it forms the basis for comprehending climate change. GHGs, like carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and fluorinated gases, act like glass panes in a greenhouse. These gases allow sunlight to enter the atmosphere while trapping some of the heat radiating from the Earth’s surface. This natural process, known as the greenhouse effect, is vital for maintaining Earth’s temperature within a range suitable for life.

Much like how a greenhouse keeps plants warm by trapping heat inside, GHGs act as a natural insulating layer, preventing some of the outgoing heat from escaping back into space. Without this greenhouse effect, Earth’s average surface temperature would be significantly colder, rendering the planet inhospitable to life as we know it.

While some GHGs occur naturally, some are attributed to human activities. Activities such as combustion of fossil fuels, industrial processes, and deforestation have increased the concentration of GHGs in the atmosphere significantly. This enhanced greenhouse effect leads to an accumulation of heat, resulting in climate change.

What Are Some Common GHGs?

Carbon Dioxide

Carbon dioxide (CO₂) is a greenhouse gas that is found everywhere, naturally occurring through processes such as volcanic eruptions, and it is present as part of the natural circulation of carbon among the atmosphere, oceans, soil, plants, and animals. It is one of the most commonly known greenhouse gases. However, man-made activities like combustion of fossil fuels and large-scale deforestation have led to significant increases in atmospheric CO₂ concentration. CO₂ has a Global Warming Potential (GWP) of 1, serving as the baseline for comparing the warming effect of other GHG over a 100-year period.

Methane

Methane (CH₄), a significant greenhouse gas, occurs naturally through decomposition. Sources include cattle farming, landfill waste dumps, rice farming, and traditional oil and gas production. Methane’s impact on climate change is noteworthy due to its relatively short atmospheric lifetime compared to CO₂ but significantly higher Global Warming Potential (GWP) at 29.8, according to IPCC AR6.

Nitrous Oxide

Nitrous oxide (N₂O) is another greenhouse gas which is produced through various human activities such as the large-scale use of commercial and organic fertilizers, fossil-fuel combustion, nitric-acid production, and biomass burning. Although N₂O occurs naturally as part of the Earth’s nitrogen cycle, human activities are increasing its atmospheric concentration. N₂O has a GWP that is 273 times greater than carbon dioxide over a 100-year period. One of the largest sources of N₂O emissions is agricultural soil management, followed by fuel combustion, industrial processes, and waste management.

Fluorinated Gases (Hydrofluorocarbons, Perfluorocarbons, and Sulfur Hexafluoride)

While Carbon Dioxide, Methane, and Nitrous Oxide occur naturally, industrial fluorinated gases—hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulfur hexafluoride (SF₆)— are exclusively human-made during industrial processes and do not exist naturally. HFCs, PFCs, and SF₆are industrial fluorinated gases with high global warming potentials (GWPs). Used in various applications, they contribute significantly to climate change due to their potent heat-trapping abilities and long atmospheric lifetimes.

HFCs are synthetic greenhouse gases commonly used in refrigeration, air conditioning, foam-blowing agents, and aerosol propellants. PFCs are another group of synthetic greenhouse gases used in various industrial applications, including semiconductor manufacturing and aluminium production. SF₆ is a synthetic gas primarily used in distribution equipment and electrical transmission, such as circuit breakers and switchgear, due to its excellent insulating properties. SF₆has an extraordinarily high GWP at 25,200, making it one of the most potent greenhouse gases known. SF₆ is highly long-lived in the atmosphere, with an estimated atmospheric lifetime of thousands of years.

Understanding How Different Gases Influence Climate Change

A few primary factors determine the impact of each greenhouse gas on climate change:

Atmospheric Concentrations: The concentration of GHG in the atmosphere directly influences their warming potential, with higher concentrations amplifying their collective ability to trap heat.
Atmospheric Lifespan: The length of time each gas stays in the atmosphere, known as its atmospheric lifespan, influences how widely it spreads and how long it persists.
Global Warming Potential (GWP): This measurement compares how effectively each gas traps heat compared to carbon dioxide (GWP of 1) over a 100-year period, making it easy to compare their warming impacts. Higher GWPs indicate a more significant contribution to climate change. To illustrate, much like thicker clothing provides better insulation, certain gases effectively “thicken” the Earth’s atmosphere, intensifying its warmth.

Climate Change

The increasing levels of greenhouse gases, mainly due to human activities, are significantly driving up global temperatures. This escalation intensifies the impacts of climate change on ecosystems, weather patterns, and communities worldwide. Rising GHG emissions heighten climate risks, leading to rising sea levels, more frequent heatwaves, increased occurrences of floods and droughts, disruptions to ecosystems, loss of biodiversity, and a surge in severe weather events like hurricanes and wildfires.

Climate Change Risks on Agriculture Sector

Climate change can pose several risks to the agriculture sector, including extreme weather events such as droughts and floods. These events can significantly impact oil palm yield, leading to fluctuations in financial performance. For example, drought or excessive rainfall can reduce Fresh Fruit Bunch (FFB) production due to disruption of the vegetative cycles or disruptions in fertilizer application programs. To mitigate these risks, Musim Mas employs measures such as satellite monitoring to identify and monitor hotspots in and around concessions. Additionally, initiatives like the Fire-Free Village Program (FFVP) educate local communities on best agricultural practices and the risks associated with using fire for land preparation.

What Is Musim Mas Doing to Reduce Our GHG Emissions?

Musim Mas is dedicated to accelerating our climate action efforts. While we strive for a 55% reduction in our upstream GHG emissions by 2025, we’re actively pursuing multiple initiatives to shrink our Group’s carbon footprint further. In 2022, we have signed up to the Agricultural Sector to 1.5C Pathway and have signed a commitment with the Science Based Target initiative (SBTi) in 2023 to achieving net zero by 2050 following the 1.5C scenario pathway. Both our near term and net zero targets are undergoing validation process by the SBTi.

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Synthetic Greenhouse Gases (2021) DCCEEW. Available at: https://www.dcceew.gov.au/environment/protection/ozone/ozone-science/synthetic-greenhouse-gases (Accessed: 15 April 2024).
Sulfur Hexafluoride (SF6) Basics (no date) EPA. Available at: https://www.epa.gov/eps-partnership/sulfur-hexafluoride-sf6-basics (Accessed: 25 April 2024).
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