Basic knowledge about climate and environment
Are you familiar with the concepts of climate and environment and their significance when it comes to emissions from our resource use?
Enhance your basic knowledge of greenhouse gases and air pollution in this knowledge article, which introduces you to a range of facts collected from various knowledge institutes and agencies.
To begin with, it is essential to know the difference between climate and environment.
What is the difference between climate and environment?
Climate is a global issue and becomes a challenge when there is a too high concentration of greenhouse gases in the atmosphere. The global effect of too high concentrations of greenhouse gases contributes, for example, to more extreme weather conditions.
Environment is a local issue, which has consequences for the surrounding areas. A high exposure to pollution affects, for example, air quality and our breathing, but it can also have consequences for life in the seas.
Read also: “How to protect your workplace from dangerous gases” from Hans Buch’s knowledge universe
Read also: “LED lights: Great savings for economy and CO2” from Hans Buch’s knowledge universe
What are greenhouse gases? (Climate)
Greenhouse gases are internationally called greenhouse gases (GHG). A too high concentration of greenhouse gases is a contributing cause to the greenhouse effect, which affects the climate on Earth.
Below you will find three examples of greenhouse gases that are worth keeping an eye on.
CO2 = carbon dioxide
The international term is carbon dioxide and is characterized by having one carbon atom (C) and two oxygen atoms (O).
CH4 = methane
Methane consists of one carbon atom (C) and four hydrogen atoms (H).
N2O = nitrous oxide
N2O is popularly called nitrous oxide and is also known as nitrogen dioxide. The international term is nitrous oxide. Nitrous oxide consists of the molecule dinitrogen (N2) and one oxygen atom (O).
CO2 equivalent – a common term
You will often encounter a description that defines a collective and simplified account of CO2, which in reality refers to a common term for all greenhouse gases.
Equivalent (abbreviated eq.) in the word’s meaning is something that “corresponds to” something else. When you encounter CO2-eq as a term (eq = equivalent), it thus refers to the total emitted greenhouse gases.
In scientific journals, you may encounter the term CO2-eq, while it is often simplified to CO2 in more general descriptions.
How much do the different CO2 equivalents affect?
Emissions from CO2, CH4, and N2O have different effects on our climate and occur in different amounts. The differences are defined based on how potent they each are and how long a degradation time in the atmosphere they each have.
Different sources indicate varying ratios, but below you get an impression of the differences between the three mentioned examples of greenhouse gases for a better understanding of the relationships between them.
| Greenhouse gas | Chemical formula | CO2-eq (factor) | Degradation time (lifetime in the atmosphere) |
| Carbon dioxide | CO2 | 1 | Approx. 50-200 years |
| Methane | CH4 | Approx. 25-28 | Approx. 12 years |
| Nitrous oxide | N2O | Approx. 298 | Approx. 114 years |
In short, this means that CH4 and N2O have a stronger impact on the atmosphere than CO2, but that CO2 potentially has a longer degradation time in the atmosphere. Therefore, CO2 is the most important greenhouse gas to keep an eye on. This should also be seen in light of estimates from the Danish Energy Agency and DMI, which estimate that CH4 and N2O account for a combined share of emissions of 20% and 4.6% respectively of the human-induced increase, while CO2 accounts for 55%.
How much CO2-eq do we emit from Denmark?
According to Statistics Denmark, we emitted 44 million tons of CO2-eq from Denmark in 2021, equivalent to 7.5 million tons of CO2-eq per inhabitant in Denmark. In 2020, the figure was 65 million tons of CO2-eq, equivalent to 11 million tons of CO2-eq per inhabitant in Denmark.
What is air pollution? (Environment)
Pollution is about human activities where there is a release of environmentally harmful substances. Pollution can also be about noise and the conditions at a given place in the sea.
Air pollution often has a higher concentration in larger cities than in rural areas, and a focus area in many major cities around the world is therefore to reduce pollution sources through political incentives. An example is a ban on vehicles with diesel combustion engines, which pollute more locally than other vehicles.
Read also: “When air quality is crucial” from Hans Buch’s knowledge universe
Here are three examples of air pollution worth keeping an eye on, which can have harmful and potentially lasting consequences for your skin, lungs, and breathing.
NOx = nitrogen oxides
Nitrogen oxides are a chemical compound between nitrogen (N) and oxygen (O). The small ‘x’ indicates a common term for NO and NO2. NO occurs at high temperatures in, for example, a combustion engine. In the air, NO is converted to NO2. Nitrogen inhibits oxygen saturation and can lead to loss of biodiversity and promote the growth of algae in water bodies.
SO2 = sulfur dioxide
Sulfur dioxide is the most frequently occurring chemical compound between sulfur (S) and oxygen (O). You may also encounter the terms sulfur monoxide and sulfur trioxide under the overall description sulfur oxide (SOx).
PM2.5 = Particles smaller than 2.5 µg (microgram)
Particles are small substances in the air and are divided into coarse, fine, and ultrafine particles defined by size. PM2.5 (fine particles) thus have a size of less than 2.5 micrograms (one-millionth of a gram). Similarly, you may encounter the term PM10 (coarse) and P1.0 (ultrafine).
Sources
- Statistics Denmark: “Emissions of greenhouse gases”
https://www.dst.dk/da/Statistik/temaer/klima - BLB.dk – Sustainable Agriculture: “Knowledge about CH4 and N20” (2022)
http://blb.dk/wp-content/uploads/2022/03/Viden-om-metan-lattergas-lavbundsjorde.pdf - Experimentarium: “Climate – read about climate, climate change, and global warming”
incl. Danish Energy Agency and Danish Meteorological Institute (DMI)
https://www.experimentarium.dk/klima - DR News: “Climate changes rage: Understand why experts always talk about CO2” (2018)
https://www.dr.dk/nyheder/viden/klima/klimaforandringerne-raser-forstaa-hvorfor-eksperterne-altid-taler-om-co2 - Lung Association: “What are particles?”
https://www.lunge.dk/luft/viden-hvad-er-partikler - Ministry of Environment: “Air pollution with NOx“
https://xn--miljtilstand-yjb.nu/temaer/luftforureningen-i-danmark/luftforurening-med-nox/ - Crowcon: “Understanding air pollutants: A guide to sulfur oxides (SOx)”
https://www.crowcon.com/da/blog/understanding-air-pollutants-a-guide-to-sulphur-oxides-sox/ - Danish Environmental Consultancy (DMR): “What are particles?”
https://www.dmr.dk/indeklima-luftforurening/luftforurening-miljoeraadgivning/partikler-koncentration-maaling/
