- What causes global warming?
- Why is climate change a serious problem?
- What does climate neutrality mean? What is the difference between CO2 -neutral and climate neutral?
- What is the Global Warming Potential (GWP) and what do CO2 equivalents (CO2e) mean?
- Which sectors are particularly affected?
- How much is one tonne of CO2?
What causes global warming?
Climate change is caused by the greenhouse effect: Greenhouse gases in the Earth's atmosphere allow solar heat to enter the atmosphere, but hinder its radiation back into space. Many of these gases are natural components of the Earth's atmosphere. However, human activity has greatly increased the concentration of some greenhouse gases. CO2 is the greenhouse gas that is produced most by human activities in terms of quantity: 63% of the global warming caused by humans is attributed to it.
The CO2 concentration in the atmosphere is 40% higher today than at the beginning of industrialisation. Other greenhouse gases are also emitted in smaller quantities, but they hinder the radiation of solar heat back into the universe thousands of times more effectively than CO2 . 19% of man-made global warming is due to the greenhouse gas methane (CH4 ), 6% to nitrous oxide (N2 O). Fluorinated gases account for most of the rest. The amount of greenhouse gases naturally occurring in the atmosphere is increasing enormously, mainly due to the use of fossil fuels, deforestation of rainforests and livestock farming.
Why is climate change a serious problem?
Rising average temperatures and steadily rising sea levels are just two of the many impacts of climate change. It leads to a change in climate variability - strong short-term climate fluctuations and more frequent extreme weather events such as heavy rain or hot summers are the result.
Particularly threatening risks are the reduced quality and quantity of drinking water and growing conditions for staple foods. The changed or prolonged occurrence of biological allergens (e.g. pollen) and the increased occurrence of so-called vectors (disease vectors such as ticks or mosquitoes) are also cause for concern. The shift in the periods in which plants grow, flower and bear fruit also has an impact on agricultural production.
The economy and transport are also affected: Roads and railways are washed out by heavy rain and suffer from high temperatures, inland waterways suffer from high or low water. In addition, many power plants draw their cooling water from rivers and feed it back in heated: If the river water is too warm or severely depleted by summer heat, power plants have to be shut down in an emergency.
What does climate neutrality mean? What is the difference between CO2 -neutral and climate neutral?
Climate neutrality is the state of equilibrium between the emission of carbon and its absorption from the atmosphere in so-called carbon sinks. This means that climate neutrality is achieved when no greenhouse gases are emitted in excess of those that can be absorbed by nature or other sinks.
In addition to greenhouse gases, however, other indicators of global warming also play a role, such as soil and water contamination, raw material consumption and biodiversity. Looking at all environmental impacts is indispensable for the climate, but it is very complex and requires a lot of effort.
Therefore, in line with the United Nations Framework Convention on Climate Change, the focus is initially on the first step towards climate neutrality: greenhouse gases (CO2 neutrality). However, in order to create binding definitions and statements on climate neutrality, the ISO 14068 standard is currently being developed at the international level - until now, climate neutrality has usually been assessed on the basis of PAS 2060.
What is the Global Warming Potential (GWP) and what do CO2 equivalents (CO2e) mean?
When drawing up greenhouse gas balances (carbon footprints), as the name suggests, not only carbon dioxide but also other climate-damaging gases (greenhouse gases) are considered. These climate-relevant gases were defined in the Kyoto Protocol and assessed annually by the Intergovernmental Panel on Climate Change (IPCC).
In addition to CO2 , gases such as methane (CH4 ), which is mainly released by agriculture and gas leaks, are also included in the balance. Also included are various coolants, nitrous oxide (N2 O) from fertilisers and the chemical industry, and sulphur hexafluoride (SF6 ), which is used as an insulating gas in high-voltage technology.
All of these additional gases have a significantly greater impact on the climate than CO2 . In order to be able to compare the relevance of the gases more clearly, the so-called "Global Warming Potential" (GWP) was defined.
The GWP of methane, based on the effect over 100 years, has the value 28. This means that the effect on the climate of 1 t of methane is just as damaging as that of 28th of CO2 . Partially halogenated or perfluorinated hydrocarbons in particular often have four-digit GWP values. The scale goes up to SF6 with a GWP of 23,500.
In order to be able to present carbon footprints in a comparable way, the total amount of greenhouse gas emissions is therefore also stated in so-called CO2 equivalents (CO2 e) in addition to the breakdown into the individual gases. Here, non-CO2 greenhouse gases are converted into CO2 e via their GWP.
An example illustrates this:
If a company had annual emissions of 100 t CO2 and 1 t CH4 , the company's carbon footprint would be 128 t CO2e.
Which sectors are particularly affected?
Responsibility for environmental protection affects all industries. However, emission-intensive -sectors such as energy production or heavy industry (steel, aluminium, etc.), for which concrete measures have already been defined in the climate package, play a special role. The ¬focus is also on companies whose products are delivered directly to end consumers (B2C), such as food or car manufacturers and the public sector. The food industry and trade in particular can no longer avoid the topic of greenhouse gas balancing and climate neutrality.
In the B2B sector, climate neutrality is playing an increasingly important role in the awarding of contracts; in the B2C sector, it can influence the public image, sales figures and thus market shares. As an affected company, you can find more information here.
How much is one tonne of CO2?
The carbon footprint is indicated by the amount of CO2 e in tonnes. But how can you imagine a tonne of CO2 ? Here are a few examples:
- Driving 9500 km with one car
- heat an average flat for 2 months
- a flight for one person from Brussels to Marrakech
(~ 2350 km) - The amount of CO2 that a beech tree binds in about 80 years of growth
- The volume of a cube made of one gaseous tonne of CO2 would have an edge length of eight metres under normal conditions