The Earth as an Energy System
First published on December 16, 2015
The planet Earth is one of about ten planets orbiting the Sun. The Sun is a nuclear fusion reactor - its immense gravity crushes hydrogen atoms together, fusing them to become helium atoms and releasing tremendous amounts of energy whilst doing so.
When you look at the planet Earth as a whole, it is forgivable to define the system boundary as the planet and its atmosphere. This is a common mistake. The Earth is constantly bombarded by energy from the Sun, it is continuously receiving energy from the Sun. We think of it as mostly visible light energy but the truth is, the Earth receives the full spectrum of light energy from the Sun, including infrared, far infrared and at the other end of the spectrum, ultra-violet light.
Infrared light is of a longer wavelength, lower frequency while ultraviolet light is of a shorter wavelength and of a higher frequency than visible light (300-800 nm wavelengths). The constant is its speed, which is 299,792,458 m/s.
Energy cannot be created or destroyed. It just changes its nature, from one form to another. From light to heat, from kinetic to potential and vice versa. When mass is converted to energy as in
E = mC^2
a tremendous amount of energy is released. This energy is not created out of nothing, it is released from the potential energy locked up in the atoms of matter.
So, we have the planet Earth orbiting around the Sun and it is constantly, continuously, relentlessly, receiving energy from the Sun.
The ultraviolet light is very energetic and problematic for life on Earth. It causes skin cancers, glare, headaches, fades colour and degrades various materials.
Luckily, the Earth is shielded by an ozone layer, that reflects the ultraviolet light back into space. When the ozone layer is thin or non-existent, due to chemicals such as CFCs, it lets in ultraviolet light, causing problems on planet Earth. Ultraviolet light of a particular frequency can penetrate our skin and cause damage to the DNA in our cells.
Life on Earth, by definition, exists in its biosphere - consisting a thin crust of its surface and the lower layers of its atmosphere.
Plants grow, animals roam, fish swim and birds fly in the biosphere. The Earth is about four billion years old, the Universe about 12 billion years old.
You'd think that if the Earth has been bombarded by energy from the Sun for four billion years, it'd be burned to a crisp by now. Well, in its earlier history, it was. Over time, the atmosphere was created, the ozone layer was created and they have shielded the Earth from the some of the harshest energy from the Sun, while sustaining and nourishing life in the biosphere.
The really important point we need to remember is that the Earth is not in a steady state, not even in a state of dynamic equilibrium. This is because the Sun is relentlessly adding energy to the planet as a whole.
What happens to this energy? This "excess" energy that is preventing the planet to be in equlibrium? It is converted to other forms of energy and stored. From light to kinetic to potential. Plants do this for us by photosynthesis. Plants take light energy and convert it to chemical energy. Some of it used up by the plant in living processes and much is stored in wood, in its leaves, in its tubers. Basically, atoms of mostly hydrogen, oxygen, nitrogen and carbon, together with trace amounts of about 20 other elements (eg magnesium, sulphur, boron, copper, iron and etc) are converted to wood, tubers, fruits and leaves using energy from the Sun.
This process of photosynthesis occurs wherever there is sunlight and plants, not just in your house plants but also in forests, including, but not limited to, the large tracts of rainforests in the Amazon, Borneo, South-east Asia and also in temperate forests.
Every time we cut a tree, we are preventing energy from the Sun from being stored as potential energy. We are allowing light to heat up the Earth and dissipate through a process called entropy. As energy is not destroyed, it just warms up the whole Earth. This is just one aspect of global warming.
Another aspect is what is referred to as the Greenhouse Effect. Just as ozone rises to the higher reaches of the the atmosphere to form the ozone layer, greenhouse gases (carbon dioxide, methane and others) rise up and act as an insulation layer or mirror. Some of the Sun's energy is reflected off the Earth's surface and goes off into space. The greenhouses gases act as a blanket of insulation or a mirror preventing the reflected energy from the Earth's surface from going into outer space. It does this by reflecting the energy back to the Earth's surface, warming it and the atmosphere up even more.
So what is the solution to global warming?
Cut down less trees. Grow more trees. Make sure the size of forests is increasing, not decreasing.
Cut down on greenhouse gas emissions. Use forms of energy that does not release greenhouse gases. Phase out the internal combustion engine. Use more electricity instead.
Generate electricity by using processes that do not generate greenhouses gases.
Reduce the human population from the current 7.25 billion to 1 billion. The human species is not the only lifeform on planet Earth. In fact, the human species has only been around for about 200,000 years. Fifty years ago, there were less than three billion of them around.
Their rapid population growth had lead to habitat destruction, resource depletion, species extinction, pollution, and other ills. Rainforests are cut down to build cities, houses, offices, factories, and also to create farmland to produce food (wheat, soy, oil palm, cattle), clothes (cotton) and housing to house, feed and clothe these humans. These humans also want "stuff," so factories are built to give them jobs, create the stuff they need and these factories in turn need raw materials (iron ore, bauxite, and etc) which result in resource depletion, habitat destruction, species extinction and pollution. If these factories run on fossil fuels, they emit greenhouse gases, smoke, dust and what we generally call air pollution. Waste in water, such as heavy metals, pollutes it.
So we really need new ways of doing things. Business as usual will not save us. Education will. Trying out new ways of doing things may. We have to be benign in our activities. Reverse the trend. Be different. Its really okay. We are all different anyway.
Yet in another way, in a very real sense, we are all the same, all members of the one human species, all members of the same race, the human race.
Everything we do today and for the rest of our lives will leave its mark, have an impact, have consequences.
Question is, what do you want that impact to be? What enduring legacy to you want to leave behind?
Copyright 2003-2018 Azlan Adnan Legal Notice
Copyright 2003-2011 Azlan Adnan. This blog post is sponsored by The Green Party of Malaysia
