Emissions
Emission means (when in context of climate and sustainability) the release of substances directly into the air or atmosphere over a specified area and period of time that pollute or harm the environment including the health of humans and animals. One class of these gases that harm the environment are greenhouse gases (GHG). When greenhouse gasses get emitted into the atmosphere they enhance the greenhouse effect of planet earth and cause the surface temperature to rise. Greenhouse gases are causing the climate change of planet earth.
What is the difference between emission and imission?
Emission means the mass of substances released into the atmosphere over a period of time. Imission is the concentration of pollutants orf substances that harm the environment in the atmosphere that we can measure.
Greenhouse gases
What is the definition of greenhouse gases?
Greenhouse gas (sometimes indicated as GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range. As a result of the greenhouse gases in the atmosphere, planet Earth has a so called greenhouse effect. The greenhouse effect is that way that heat is traped closed to the service of the Earth due to greenhouse gases. The greenhouse gases are often described as a blanket around the Earth trapping the heat of the earth. If greenhouse gasses would not exist, planet Earth would have a average of -18 degrees Celsius instead of the 15 degrees Celsius that the average temperature is of planet Earth (at the moment). Not only planet Earth has greenhouse gases, but also Venus, Mars and Titan have greenhouse gases. Having greenhouse gases in the atmosphere is necessary for life on earth and e greenhouse gases have cycle as well. For example Carbon dioxide is a GHG that plants use to make glucose. After the glucose is formed their are four reaction that can happen to get the carbon dioxide back into the atmosphere. 1. The plant breaks down the glucose for energy to grow and releases the energy to the atmosphere, 2. Humans or animals eat the plant and break down the glucose for energy and release the carbon back into the atmosphere, 3. Plant die and decay and the glucose gets broken down by bacteria releasing the carbon dioxide in the atmosphere and number 4. Plants get burned and the glucose reacts with the oxigen and gets released into the air as carbon dioxide. New plants can grow using the carbon dioxide that is released back into the atmosphere. The release of carbon dioxide becomes only a problem under one of these conditions:
- Deforrestation: Their are much less plants to absorb the carbon dioxide resulting in a excess of carbon dioxide in the atmosphere
- Burning fossil fuels: Fossil fuels are stored glucose from plants and under particular conditions turned into a fossil fuel. The Glucose
is not part of the carbon cycle. When the fossil fuel gets burned, extra carbon dioxide gets released into the air resulting in a excess of carbon dioxide in the atmosphere.
Both these scenarios (and sometimes even combined) result in a enhanced greenhouse effect making the temperature of the earth rise.
Indurtsial revolution
Since the beginning of the industrial revolution humans have increased the atmospheric concentration of carbon dioxide massively. AWith this amount of greenhouse gasses in the atmosphere the average temperature of planet earth could increase by 2 degrees Celsius with massive consequences. The vast majority of the emission of greenhouse gasses is due to burning fossil fuels, cement production, fertilizers production and deforestation.
The Earth's atmosphere
The earth atmosphere consists of 3 main gases: 78% nitrogen (N2) 21% Oxigen (O2) 0,9% Argon (Ar) These gases ar no greenhouse gases. What makes a gas a greenhouse gas is the ability to absorb and emit radiant energy within the thermal infrared range. Molecules containing 2 of the same atoms like nitrogen and oxigen have no net change in distributing their electoral changes when the vibrate and momoatomic molecules like Argon do not vibrate at al and both are therefor almost totally unaffected by infrared radiation. The last 0,1% of the Earth's atmosphere include greenhouse gases
What are the 7 greenhouse gases (GHG)?
- Water vapor (H2O)
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Ozone (O3)
- Industrial gases:
- Chlorofluorocarbons (CFCs and (HCFCs)
- Hydrofluorocarbons (HFCs)
- Perfluorocarbons (PFCs)
- Sulfur hexafluoride (SF6)
- Nitrogen trifluoride (NF3)
Air pollutants like ammonia (NH3) are the other type of gaseous emissions from agriculture. They are not greenhouse gases, but they do negatively impact on human and animal health while also damaging ecosystems.
What are the 4 largest sources of emissions?
Carbon dioxide (CO2) accounts for about 76% of total greenhouse gas emissions. Methane, primarily from agriculture, contributes 16% of greenhouse gas emissions and nitrous oxide, mostly from industry and agriculture, contributes 6% to global emissions
Three groups or scopes
Greenhouse gas emissions are categorised into three groups or 'Scopes' by the most widely-used international accounting tool, the Greenhouse Gas (GHG) Protocol. Scope 1 covers direct emissions from owned or controlled sources. Scope 2 covers indirect emissions from the generation of purchased electricity, steam, heating and cooling consumed by the reporting company. Scope 3 includes all other indirect emissions that occur in a company’s value chain.
| Scope 1 | Scope 2 | Scope 3 |
|
Purchased electricity, heat and steam | Purchased goods and services
Business travel Employee commuting Waste disposal Use of sold products Transportation and distribution (up- and downstream) Investments Leased assets and franchises |
