Energy Sciences

Fossil Fuels and Energy Use

Fossil fuels are a non-renewable resource that humans rely heavily upon for our energy usage.  Fossil fuels are the organic remains of biological materials “left in the ground during the Carboniferous Period between 360-286 million years ago”.⁵ During this era, the land over a majority of the Earth was covered by swamps. Over time, the marine biomass of dead plants and animals sank to the bottom of the swamps and oceans where it formed a substance called peat. The peat was covered by various materials, including sand, clay and silt. Depending on the type of organic matter, surrounding material, temperature, amount of pressure and length of time the biomass was buried, the peat transformed into various fossil fuels. The major types of fossil fuels are coal, oil and natural gas.⁶

People have been burning fossil fuels in large amounts for our needs at an unchecked rate. In Energy for a Sustainable World, authors Nicola Armaroli and Vincenzo Balzani state that “over 80% of energy [currently] used by mankind comes from fossil fuels.”⁷ Americans are particularly gluttonous in their energy consumption, with average Americans consuming twice as much as Europeans, four times that of Chinese, 17 times Indians and 240 times more than Ethiopians.⁸ “It has been calculated that if all the world’s 6.8 billion inhabitants were to live at current American ecological standards, we should look around for another four Earths to accommodate them.”⁹

Fossil fuels are considered to be non-renewable because they take millions of years to form. They do, however, have multiple economic advantages over other forms of energy. Fossil fuels continue to power economic growth and industrialization of nations,¹⁰ as well as sustaining our traditional way of life and maintaining our expectations of thriving in a global economy. The application of fossil fuels is pervasive in today’s modern world, being employed in electricity production, heating, transportation and many other industries. Additionally, fossil fuels are fabricated into everyday products like furniture, deodorants, detergents, plastics and appliances. Currently, our dependence on fossil fuels is ingrained in almost everything we do and is a fundamental part of many of our social and economic systems. Breaking this reliance on fossil fuels is one of the major challenges for humanity in the 21^st Century.

Climate Change and the Greenhouse Effect

One catastrophic byproduct of our abundant use of fossil fuels is the effect on Earth’s atmosphere. When fossil fuels are burned for energy, carbon dioxide (CO₂) is released into our atmosphere. When fossil fuels combust or burn, they combine with oxygen to form both carbon dioxide (CO₂) and water (H₂O).  Heat energy is also produced as a result of fossil fuel combustion. This energy is stored in chemical bonds that hold the carbon and hydrogen atoms together. When the atoms are rearranged, the bonds break, resulting in the release of energy. The amount of CO₂, water and energy produced from each reaction depends on the fossil fuel’s carbon and hydrogen content.¹¹

Many natural processes release carbon and oxygen into the environment, and much CO₂ is absorbed or removed by the oceans and plants’ photosynthesis. However, the amount of CO₂ being produced as a result of our consumption of fossil fuels overwhelms the Earth’s capacity to compensate. If all of humanity’s carbon emissions were halted today, it would still take the Earth 100 years to naturally absorb the current levels of CO₂.¹²

The extra CO₂ being produced rises into the atmosphere, where it accelerates Earth’s natural greenhouse effect. Energy comes to the Earth from the sun as sunlight. After being absorbed by the Earth, the leftover energy is radiated into space in the form of infrared radiation. Our atmosphere captures some of the outgoing infrared radiation, keeping our planet warmer than it otherwise would be. Without an atmosphere, the Earth would average about -3°F or -16°C around the world, temperatures that aren’t suitable for sustaining most life that exists. With the atmosphere in place, average global surface temperatures are 86°F or 30°C.¹³ Due to the increased CO₂ in the atmosphere as a result of fossil fuel consumption, much more infrared radiation is trapped and temperatures on Earth are pushed higher. This phenomenon is called global warming.

How do we know that the additional CO₂ in the atmosphere is caused by humans? One method of answering that question is to study human activity, particularly our burning of fossil fuels since the Industrial Revolution. There are several stationary sites worldwide where large amounts of CO₂ are detected in the atmosphere. Not surprisingly, these areas lie above North America, Southeast Asia and Europe, three of the most industrialized regions on Earth.¹⁴ Over the last 2,000 years, concentrations of the three greenhouse gases -- CO₂, methane (CH₄) and nitrous oxide (N₂O) -- remained at low levels and relatively unchanged but began to spike considerably coinciding with the Industrial Revolution around 1750 and an increase in deforestation as the number and size of cities expanded. From 1850 to 2000, the total amount of CO₂ in the atmosphere increased from 280 parts per million (ppm), where it had averaged since before 0 C.E., to 375 ppm.¹⁵ In particular, our energy use practices since 1950 have had a significant impact on the atmosphere. The increase in atmospheric concentrations of all greenhouse gases after 1950 represents 75% of the total variation since the start of the Industrial Revolution.¹⁶

An affirmative answer to the question of whether humanity is to blame for the higher concentration of CO₂ is also confirmed by looking at carbon isotopes. Carbon is composed of different isotopes, carbon-14, carbon-13 and carbon-12, with carbon-12 being the most common. Carbon-12 has 6 protons and 6 neutrons, while carbon-13 has 7 neutrons and the very rare carbon-14 has 8 neutrons, making it the heaviest form of carbon. CO₂ that is produced from burning fossil fuels has a different isotopic composition than that of the CO₂ that occurs naturally in the atmosphere. Since fossil fuels are ultimately derived from ancient plants and animals, they are depleted of any carbon-14 that is radioactive and would have decayed long ago. Fossil fuel CO₂ also has low amounts of carbon-13. “By comparing the amount of carbon-14 in carbon dioxide in the air, scientists are able to recognize the telltale signature of fossil fuels as the source of these emissions.”¹⁷ Carbon emissions from volcanic activity can also be dismissed since CO₂ from volcanic activity has a higher level of carbon-13 relative to carbon-12. In our atmosphere, there is a trend toward a low ratio of carbon-13 to carbon-12. Thus, volcanoes are not to blame for climate change.¹⁸

In The Long Thaw, author David Archer asserts, “If CO₂ emissions continue it is predicted to be 3-5% warmer by 2100 than 1950.”¹⁹ Global warming is already having devastating effects on our oceans and polar ice regions. It also has the potential to lead to significant sea level rise, more frequent severe weather events (hurricanes, storms, droughts, wildfires) and a tragic loss of biodiversity. Climate change is a reality that must be addressed. As the Intergovernmental Panel on Climate Change states, “Scientific evidence for warming of the climate system is unequivocal.”²⁰

Average global temperature rise not only leads to a warmer surface of the planet but it has also led to oceans absorbing much of the heat. With 90% of the sun’s energy going to the oceans, they absorb 20 times more heat energy than the atmosphere. Covering 70% of the Earth, the oceans also absorb a majority of the CO₂ produced worldwide. The oceans’ carbon reservoir has a greater capacity than the atmosphere’s even though it is thinner (4 km compared to the 8 km depth of the atmospheric carbon reservoir). The ocean’s ability to absorb CO₂ is dependent on proper circulation of warm surface water mixing with cold seafloor water. The cold water of the oceans envelops CO₂ in the carbon reservoir layer and then bears it downward into the depths. But rising sea temperatures threaten this circulation cycle. Since cold water is denser, a greater disparity between the temperatures of surface and deep ocean water causes colder water to stay down. Climate change could bring about the stagnation of our ocean water and force the atmosphere and plant photosynthesis to take the brunt of CO₂ absorption.²¹ This potential slowing or stagnation of our ocean water could have disastrous effects on our planet including changing weather patterns. Places like Europe could potentially see much colder winters and much hotter summers.²²

Global warming is also causing a rise in the frequency and destructiveness of extreme weather events. An increase in ocean surface temperatures leads to more frequent spawning of hurricanes. It also contributes to the severity of those hurricanes. More frequent and extended heat waves are occurring around the world, with high temperature records regularly being exceeded.²³ In the summer of 2018, 22% of populated and agricultural regions located above 30 degrees latitude across the northern hemisphere suffered simultaneous extreme heat conditions. This sort of concurrent high temperature event affecting such an expansive number of locales simply did not occur before 2010.²⁴ The extreme heat has intensified drought conditions and fueled more disastrous wildfires. In 2018, California suffered its most expensive damage from wildfires in the state’s history with insurance claims in November alone topping $12 billion.²⁵

A byproduct of the enhanced greenhouse effect caused by higher concentrations of CO₂ in the atmosphere, global warming has triggered unprecedented melting of the Greenland and Antarctic ice sheets.²⁶ Across the world, glaciers are shrinking. Climatologists have been measuring Arctic sea ice dimensions using weather satellites since 1979 and have determined that the ice has been declining at a rate of 12.8 percent per decade since then. In 2012, the ice sheet over Greenland suffered its worst melting ever. The summer of 2019 is threatening to be just as damaging to the Arctic ice, with some extreme Greenland temperatures in June peaking 40°F above normal.²⁷

The areas covered by the ice sheets provide habitats to a great variety of wildlife; the loss of sea ice can have devastating effects on natural ecosystems. In particular, the polar bear faces a dire outcome as a species unless the course of global warming is drastically changed. Many human communities in the Arctic region, dependent on snow packs for their water, find those water sources less and less available as snow cover decreases yearly.

Due to the added water from melting ice sheets and glaciers, sea levels are rising. This causes communities and towns along coastal areas to be displaced, as well as disrupting fragile natural ecosystems along the shoreline. From 1993 to present, average sea levels are rising 3.3 mm per year, resulting in an increase of 91 mm since 1993.²⁸