Next concept as far as the the climate change is concerned it is the concept of climate system. The United Nations Framework Convention on Climate Change (UNFCCC) defines the climate system as the totality of the atmosphere, hydrosphere, biosphere, and geosphere and the interactions among them [IPCC AR6 Glossary][UNFCCC]. This is the basic of, you know, climate change—the kind of interaction that is taking place within all the components of the climate system.
Visual suggestion: Show a layered diagram of Earth—atmosphere, hydrosphere (oceans, rivers), biosphere (plants, animals), geosphere (land)—with arrows showing interactions.Now let us see one by one the conference and how it is important for the climate system to be dynamic because the climate system is very complex system and it’s a very dynamic in nature. The climate system is basically powered by the solar radiation [IPCC AR6 Ch. 1][NASA].
Visual suggestion: Sun sending rays to Earth, powering physical processes.Since the surface temperature has been relatively constant over many centuries, the incoming solar radiation (shortwave radiation, SWR) must be nearly in balance with the outgoing longwave radiation (LWR) [IPCC AR6]. There should be a balance between the SWR and the LWR.
About half of the short wave radiation (~49%) is absorbed by the Earth’s surface, about 30% of the short wave radiation is reflected back to space (Earth’s albedo), and roughly 21% is absorbed by the atmosphere [IPCC AR6 WGI FAQ 1.1, NASA]. This is with respect to the short wave radiation.
Visual suggestion: Solar energy budget pie chart or energy-flow diagram (arrows for absorbed, reflected, transmitted).With regard to the law, that is the radiation that is emitted from the surface, it is largely absorbed by radiatively active gases, in other words the greenhouse gases like water vapor, carbon dioxide, methane, nitrous oxide, and other related greenhouse gases [IPCC AR6 WG1 Ch. 7]. The long wave radiation is also called terrestrial radiation, and they are long wave because of the Earth’s surface temperatures. On average, Earth’s surface temperature is about 15 degrees Centigrade (59°F) [IPCC AR6 Summary]. Since the Earth’s surface temperature is 15 degrees Centigrade, the irradiation emitted by the Earth’s surface is of long wavelength [IPCC AR6].
The downward-directed component of this longwave radiation heats the lower atmosphere and this process is popularly called the greenhouse effect [IPCC AR6; NASA].
Visual suggestion: Greenhouse effect cartoon—arrows bouncing off greenhouse gas molecules and heading back toward Earth's surface, with surface warming.Components of Climate System
Atmosphere
So, now, let us see one by one the component of the climate system. The first and foremost component is the atmosphere. This component is very unique and it is most unstable.
Why?
Because the composition, look at the composition, it is constantly changing. Nevertheless, the dry atmosphere composed mainly of the nitrogen (N₂), oxygen (O₂), and argon (Ar). If you look at the volume concentration, it is not changing and it is almost constant as far as the nitrogen gases containing oxygen and argon is concerned (Nitrogen ~78%, Oxygen ~21%, Argon ~0.9%) [IPCC AR6, 2023].
In fact, these three important gases never interact with whether it is an incoming solar radiation or long wave radiation; it is not interacting and in that way it is, you know, less significant with the Earth’s energy budget (constant gases). But there is a certain group of gases called trace gases (Definition: Trace gases are atmospheric gases present in relatively small, variable concentrations, generally less than 1% of the total atmosphere) because their quantity is very, very less but the kind of contribution to the Earth’s energy budget is tremendous. These gases are called greenhouse gases or radiatively active gases [WMO 2025].
We know that the radiatively active gases are carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), ozone (O₃). The quantity is very, very less—in fact, if you look at the volume proportion, it is less than one percent. But their contribution to the Earth’s energy budget is immense and very important for the greenhouse effect. And, our existence, the Earth’s surface temperature, which is about 15 degrees Centigrade on average, is because of the greenhouse effect [IPCC AR6, 2023].
When you look at the gases, water vapor particularly is a very significant naturally occurring greenhouse gas, and its concentration is in the order of about 1%. But it’s a very significant greenhouse gas. And when you look at the water vapor, carbon dioxide, and ozone, these three important gases also absorb the shortwave radiation in addition to the longwave radiation. This is with regard to the greenhouse gases [IPCC AR6, 2023].
[Infographic suggestion: Pie chart of atmospheric composition—highlighting nitrogen, oxygen, argon, and a segment for “trace greenhouse gases”—plus a schematic showing GHG absorption of IR radiation.]Hydrosphere
The second important component is the hydrosphere. This hydrosphere is a component that comprises all the liquid surface and subterranean water, both fresh water and saline water. It includes rivers, lakes, aquifers and even the saline water of oceans and seas—all are part and parcel of the hydrosphere component. Of course, the major component is the ocean because it covers about 71% of Earth’s surface [IPCC AR6, 2023]; and is a significant contributor to Earth’s energy budget:
- Because this ocean body stores and transports a large amount of energy, historically immense energy stored.
- The second important aspect regarding the ocean is that it dissolves and stores great amounts of carbon dioxide. That is significant because it acts as a regulator of Earth’s energy budget and climate system [IPCC AR6, 2023].
Now let’s discuss about the circulation pattern, it’s called Thermohaline Circulation. So by definition, Remember it’s “Thermo-haline” circulation is a global-scale ocean current system driven by differences in water density, which are influenced by temperature (thermo) and salinity (haline). This “Global Ocean Conveyor Belt” moves vast amounts of water, heat, and nutrients around the planet.
Now w.r.t. climate system, this Thermohaline circulation is much slower than atmospheric circulation, mainly due to the large thermal inertia of the oceans (their capacity to store heat). This inertia dampens vast and strong temperature changes and functions as a regulator of Earth’s climate. It also acts as a source of natural climate variability, particularly on longer timescales [IPCC AR6, 2023].
[Infographic suggestion: World map showing the global ocean conveyor belt (thermohaline circulation) and pie chart of Earth's surface covered by ocean.]Cryosphere
The third important component of the climate system is the cryosphere.
Cryosphere is the ice masses such as Greenland and Antarctica, continental glaciers, snowfields, sea ice, and permafrost.
Now cryosphere has a special impact on the energy budget from several important angles:
- First, it is known for its high reflectivity (albedo), meaning it reflects a large portion of incoming solar radiation (Albedo values for ice can be as high as 0.85, meaning 85% reflected).
- Second, it has low thermal conductivity (ice is a poor conductor of heat, slowing heat transfer).
- Third, it has large thermal inertia due to its mass and heat capacity, helping to moderate temperature changes.
And to add up, these properties also influence the deep ocean water circulation through their effects on salinity and temperature gradients—the cryosphere plays a critical role in driving the Thermohaline circulation that regulates global climate [IPCC AR6, 2023].
[Infographic suggestion: Images of ice caps, sea ice, and a bar showing albedo comparison—ice vs. soil vs. ocean.]Geosphere
The geosphere impacts the climate system by regulating the Earth’s carbon cycle through the processes of carbon burial and release, which occur over geological timescales. Carbon burial refers to the storage of carbon in rocks such as fossil fuels, effectively removing carbon from the atmosphere and leading to a cooling effect. Conversely, processes like volcanic eruptions, which release large amounts of carbon dioxide (CO₂), and human-induced combustion of fossil fuels release carbon back into the atmosphere, increasing atmospheric carbon concentrations and causing warming [WMO 2025; IPCC AR6, 2023].
The movement of tectonic plates, which are massive sections of the Earth’s lithosphere that shift over the mantle, also influences climate by creating mountains and ocean basins, which in turn affect the rock cycle and modify the land surface’s albedo (reflectivity). Changes in albedo affect how much solar energy the Earth’s surface reflects back to space, thus influencing the Earth’s energy budget and climate [IPCC AR6, 2023].
Land (Lithosphere, Vegetation and Soils)
Then the fourth component is the land, known as lithosphere or the Earth’s solid surface, including vegetation and soils.
These are very important concerning the energy budget and climate system interactions. Because vegetation and soils control how solar energy received is returned to the atmosphere, this is an important aspect to note Some energy is returned as longwave (infrared) radiation that heats the atmosphere as the land surface warms. Some energy serves to evaporate water either in the soil or in the leaves of plants, bringing water back into the atmosphere and thus fueling the hydrological cycle.
The texture of the land surface—in other words, its roughness and topography—influences the atmosphere dynamically as winds blow over the land surface. This affects the movement of air and transfer of energy from one place to another [IPCC AR6, 2023].
Marine and Terrestrial Biosphere
With regard to the marine and terrestrial biosphere, this is a very important component of the climate system interactions.
The biota (living organisms) influence the uptake and release of greenhouse gases, particularly carbon dioxide through photosynthesis. Both marine and terrestrial plants store significant amounts of carbon from CO₂, playing a significant role in the carbon cycle, as well as the budget of other gases including methane and nitrous oxide [IPCC AR6, 2023].
