There are several different greenhouse gases. You should know the main ones.
The concept of Global Warming Potential (GWP) indicates that some gases are more potent greenhouse gases than others.
- Some greenhouse gases can remain in the atmosphere several decades, others for centuries before they are broken down or included in the next phase in a natural cycle.
This is one of the reasons why even if human emissions stopped today, the warming effect would continue for many years. This means that the experiment we conduct with changing the chemistry of the atmosphere from a human perspective to some extent is irreversible.
- The climate system is an interactive system consisting of five major components:
- the atmosphere,
- the hydrosphere,
- the cryosphere,
- the litosphere - land surface, and
- the biosphere,
forced or influenced by various external forcing mechanisms, the most important of which is the Sun.
Also the direct effect of human activities on the climate system is considered an external forcing.
- The United Nations Intergovernmental Panel on Climate Change (IPCC) produces a major scientific report involving up to 2500 scientists in the writing and reviewing process every 5th year.
The IPCC Third Assessment Report (TAR) states:
A climate model can be used to simulate the temperature changes that occur from both natural and anthropogenic causes.
The simulations in
a) were done with only natural forcings: solar variation and volcanic activity.
b) only anthropogenic forcings are included: greenhouse gases and sulfate aerosols.
c) both natural and anthropogenic forcings are included.
The best match is obtained when both forcings are combined, as in c).
Natural forcing alone cannot explain the global warming over the last 50 years.
- The Global Warming Potential (GWP)
This metric compares the potential climate impact of different gases compared to that of carbon dioxide.
CO2 has a GWP of 1
The exact definition goes like this:
"Global Warming Potentials compare the integrated radiative forcing over a specified period (e.g., 100 years) from a unit mass pulse emission and are a way of comparing the potential climate change associated with emissions of different greenhouse gases" (IPCC, A4R).
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