Energy, Climate, Environment

The Natural State of Affairs

Everything is a system with a set of parts or components that are linked in an organized way to serve a specific purpose. Everything that does work or performs a function can be considered to be a system in one form or another. The components operate as a complex whole and result in some observed behaviour. ¹

The earth has a natural climate system that regulates its temperature. There are 5 components of the climate system that include the atmosphere, hydrosphere, cryosphere, biosphere, and lithosphere. Each of these components is affected by the other. The natural warming process of the earth is referred to as the green house effect because it acts similarly to how a botanical greenhouse works. ²

Each of the components of the climate system has a set of variables. When the equilibrium of the variables is disturbed the system is considered to be in transition from one state to another state. The state of the system is reflected by the value of the set of variables at a given point in time. A 'discrete system' is a how system that jumps from one state to another but can only exist in one state at given point in time would be described; a 'continuous system' is one that gradually moves from one state to another. The climate system is a good example of a Continuous System that can be classified as an Open System describing how it interacts with its surrounding environment. An Open System exchanges energy and mass with its outside environment. It can be further categorized as a cascading system made up of a series of subsystems. The mass and energy involved with the Open System is passed [or cascades] from one subsystem to another. The result is that the output from one subsystem is the input to another subsystem. In the climate system the individual subsystems, as mentioned above, are the atmosphere, hydrosphere, cryosphere, biosphere, and lithosphere. The natural interaction among these subsystems can be explained by the water cycle, carbon cycle, and green house effect. ³

The Natural Green House Effect

The atmosphere is the most variable component of the climate system. ⁴ As we examine this subsystem further we will see why. The Earth's natural green house effect is a balance between the energy from the sun and the loss of that energy back into space. Approximately 1/3 of the energy that hits the earth, received in the form of solar short-wave radiation, is reflected back to space. The atmosphere absorbs some of the remaining energy, however the land and oceans absorb most of it. The Earth's surface becomes warm and consequently emits long-wave radiation toward the atmosphere. The naturally occurring green house gases that include water vapor, carbon dioxide, ozone, methane, and nitrous oxide trap and re-emit the long-wave radiation warming the atmosphere. These greenhouse gases act collectively to create a blanket effect that warms the earth by approximately 35°C (95°F). Clouds cool the surface by reflecting solar radiation and also warm it by absorbing and re-emitting outgoing long-wave radiation. ⁵ Globally the net effect is a balance between incoming solar radiation, illustrated numerically as +100, loss of short-wave radiation to space, illustrated numerically as -30, and loss of long-wave radiation to space, illustrated numerically as -70 resulting in a net effect of zero. ⁶ This illustrates our climate system working in perfect balance with equilibrium of the variables of its subsystems.

The composition of the earth's atmosphere includes 78% nitrogen, 21% oxygen and 1% other gases. It is the 1% of other gases that is of concern when we discuss the greenhouse effect, and ultimately global warming due to climate change, because this 1% is comprised of the greenhouse gases. The two most important greenhouse gases according to Maslin are carbon dioxide and water vapor. Without the natural greenhouse effect produced by water vapor and carbon dioxide the average temperature of the earth would be approximately -20°C (-4°F). ⁷

The greenhouse gases in the atmosphere act similarly to the glass panes in a botanical greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight's energy. Some of the energy passes back into space, but much of it remains trapped in the greenhouse gases, similarly to how the panes of the botanical green house traps the heat inside, causing the earth to heat up. ⁸ When the atmosphere is in balance, and not saturated with greenhouse gases, enough energy passes back into space preventing the earth from being overheated and resulting in a rise in temperature. Without the greenhouse effect, the Earth wouldn't be warm enough for humans to live on.

Carbon dioxide and water vapor are variables in the atmosphere, a component or subsystem of the climate system. As variables, their value or amount can change. Therefore, the amount of carbon dioxide and water vapor in the atmosphere can vary on Earth. Consequently, the natural greenhouse effect has created a climate system that is naturally unstable and can be somewhat unpredictable. ⁹

The Water Cycle

The hydrosphere includes all water in the liquid phase consisting primarily of oceans but also including lakes and rivers. ¹⁰ The cryosphere encompasses all frozen water, including seasonal snowfalls, glaciers, the polar ice caps and permafrost. ¹¹ Both are involved in the water cycle, an example of a closed system transferring only energy across its boundary.

The Earth has a finite amount of water that is stored in oceans, rivers, and lakes as well as underground between rock and soil. It is also stored as solid ice in glaciers at the north and south poles and as snow on top of mountains. Ice crystals are another form in which water is stored in clouds and as vapor in the atmosphere. It is the same water that moves from the different storage areas to the atmosphere via the water cycle.

Evaporation occurs when the sun heats up the water in the oceans, rivers, and lakes changing it from a liquid to a gas causing it to rise as vapor to the atmosphere. Transpiration is another process by which vapor is released back into the atmosphere, occurring when plants release water through their leaves. Collectively the two are referred to as evapotranspiration. When the water vapor in the atmosphere cools it condenses back to liquid form and forms clouds.

Precipitation in the form of rain, sleet, snow, or hail occurs when the air can no longer hold the current amount of water. When the precipitation reaches the ground it either remains as snow and/or ice in frigid locations; is received as water back into the oceans, rivers, or lakes; or falls onto land. On land, the water either penetrates into spaces in the ground, which is the process called infiltration, or it can flow over the ground in a process called runoff ending up back into a body of water. Water that infiltrates becomes groundwater that either stays in place or moves underground until it too joins a body of water. From there, the cycle starts all over again with the same finite amount of Earth's water.

The Carbon Cycle

The biosphere includes plants on land and in the sea and all animals. ¹² The carbon cycle, a closed system transferring only energy across its boundary, is the natural recycling process of carbon atoms. Without the balanced functioning of the carbon cycle, life as we know it today, could drastically change. The carbon cycle involves the movement of carbon and carbon dioxide (CO ₂) throughout the environment. CO ₂ is one of the greenhouse gases and the one that is most influenced by the activities of humans.

Carbon is found everywhere. It is stored in the ground, found in fossil fuels, the air, certain rocks and animals' shells, and all living things. Carbon is part of the soil, is dissolved in ocean and lake waters, and is stored in plants and trees. Plants and trees use carbon dioxide from the atmosphere through photosynthesis and store the carbon as they grow. Plants release carbon into the atmosphere through a process called respiration. Decomposed plant matter becomes part of the soil and over time compacts and transforms into fossil fuels such as oil and coal.

Through the diffusion process, gases containing carbon move between the ocean's surface and the atmosphere. Ocean plants use carbon dioxide from the water for photosynthesis in the same way land plants use it. The ocean animals eat the plants to get the carbon and release carbon dioxide into the water through respiration. Decomposed water plants and animals either sink to the ocean deep or settle on the ocean floor and get buried. Water moving between the deep ocean and the surface carries carbon, some of which moves from the surface to the atmosphere. ^{1 3}

There lies the natural order of our continuous open cascading climate system. When all of the variables and exchange of energy and mass are in balance, life and the surrounding environment is just fine. Now lets take another look to see what is happening, what has already happened, and question whether our earth is still in perfect balance. Is all the beauty we visualized earlier and once enjoyed still there for us to enjoy now and for generations to come? When we look again we see that there have been significant changes to our planet. We can observe changes in our weather patterns. The quality of both land and oceans has been diminished due to pollution. Our forests have been considerably depleted. There is an increase in the occurrence of infectious and terminal diseases. Animals and insects are becoming extinct while others are growing in number. What has happened and is continuing to happen to the beauty and balance that the earth once had to offer?