Energy Futures

The debate over human-induced climate change has become a polarizing political argument. Nearly all scientists agree that burning fossil fuels by humans as an energy source has added significant amounts of carbon dioxide to the atmosphere from the combustion products. Carbon dioxide is a “greenhouse gas” that traps heat radiated from the warm Earth, warming the atmosphere and causing climate change. The people who disagree or deny that this is a problem are largely connected to the coal business or to the oil and gas industry. So-called “climate skeptics” have introduced artificial levels of uncertainty that have mired policy initiatives and stalled legislation in endless debates. These delays in addressing the problem serve but one purpose: to continue the use of fossil energy to power human technology for as long as possible at a profit to the fossil fuel industry. The delays are also making the eventual solution more expensive and technically challenging as the climate continues to deteriorate.

For the past 400,000 years, the concentration of atmospheric carbon dioxide has varied from 180 parts per million (ppm) to 300 ppm. Since 1950, levels climbed above 300 ppm and are now above 420 ppm. Nearly all scientists agree that this anomaly was caused by humans burning fossil fuels, which added carbon dioxide to the air as a combustion product. Carbon dioxide is a “greenhouse gas” that traps heat radiated from the warm Earth, warming the atmosphere and causing climate change. No other explanations for this anomaly fit the timing and the trend of the data better than human fossil fuel combustion.

Fossil fuels were latecomers to human history. Coal wasn’t widely adopted until the mid-1600s when England faced a wood shortage. Petroleum had been used for millennia as a tonic, medicine and cure-all, but was not burned for energy until it was developed as a lantern fuel in the mid-1800s to replace whale oil, which had become shockingly expensive. Natural gas was produced and used locally as a substitute for manufactured gas but did not see widespread use until interstate pipeline systems became available to transport it nationwide after World War II. The growing reliance on fossil fuel to power the manufacturing, electricity, and transportation sectors was largely a late nineteenth and twentieth century phenomenon. By the start of the twenty-first century, the economy of the United States and indeed the world had become dependent on fossil fuel.

The U.S. dependence on fossil fuels became painfully apparent during the 1973–74 oil embargo by the Organization of Petroleum Exporting Countries (OPEC). Even though the actual reduction in oil supply was only about 10%, the resulting social and economic disruption influenced U.S. foreign policy for the next 50 years. The development of shale gas and tight oil two decades later using horizontal drilling and hydraulic fracturing was the direct result of the embargo. By 2019, the U.S. was producing more oil than Saudi Arabia, and more gas than Russia. The abundant natural gas from shale led many electric utilities to convert power plants to natural gas from coal . Coal use suffered as a result, with the coal companies claiming it was due to an EPA “war on coal .” The truth is that gas is cheaper, much cleaner, and 50 percent more efficient at generating electricity.

Over the past 400,000 years, the concentration of atmospheric carbon dioxide has varied from 180 parts per million (ppm) to 300 ppm. Since 1950, levels have climbed above 300 ppm and are now above 420 ppm. Nearly all scientists agree that this anomaly was caused by the human burning of fossil fuels, which added carbon dioxide “greenhouse gas” to the air as a combustion product that traps heat radiated from the warm Earth, warms the atmosphere and causes climate change. The physics of this have been well-understood since the nineteenth century.

To maintain a technological civilization, humanity requires energy. We cannot, however, continue to obtain the majority of that energy by burning fossil fuels. There are carbon-neutral and sustainable substitutes available, including biofuels, hydrogen, wind, solar, new technology nuclear, and engineered geothermal. More exotic energy sources like nuclear fusion may be on the horizon, but the urgent need to replace fossil fuels as quickly as possible suggests that we have to use what we have available. Displacing fossil fuels with new energy sources will be disruptive and challenging, but it must be done. Government policies and leadership are necessary, because it has become obvious over the last few decades that the fossil fuel replacement will not be achieved by the “free market.” Fossil fuels should first be replaced in the electric power sector to completely decarbonize the electric grid. This should be followed by the decarbonization of the transportation sector. Many nations have pledged to become carbon neutral by the middle of the twenty-first century, but the sooner this can be achieved, the better.

The first step in replacing fossil fuels with carbon-neutral energy is to decarbonize electricity. Electric power does not create energy, but only transfers it. As such, replacing fossil fuels with carbon-neutral options as the primary power sources for electrical generation will be minimally disruptive to the economy and society. Electricity will flow as before, all appliances and devices will operate normally, and no one will know the difference except for those scientists measuring GHG levels in the atmosphere. If carbon-neutral options are used to replace fossil fuels as the heat sources for thermoelectric power plants, existing electrical generating infrastructure can be retained, saving a substantial amount of both time and money. These include biogas to replace natural gas and engineered geothermal or new nuclear technology to replace the heat from coal. The capital costs of engineered geothermal and new nuclear options will be partly offset by lower operating expenses compared to coal or old style nuclear plants. Once the electric grid is fully decarbonized, it should be followed by decarbonization of the transportation sector and the industrial sector.

Transportation accounts for about 30% of GHG emissions in the United States, and more than half of that comes from passenger vehicles. Decarbonizing transportation is as challenging as decarbonizing electricity, but in different ways. Essentially, vehicles from aircraft to automobiles that currently run on liquid fossil fuels will have to find another power source that doesn’t emit GHG. Unlike stationary electrical power plants, vehicles are mobile and thus require zero carbon power sources that are robust, light weight, portable, and quickly renewed or refilled. The current choices are electrically-powered vehicles that run on rechargeable batteries or internal combustion engines that use liquid or gaseous biofuels with net zero carbon emissions. Possible advanced options for electrical power sources include chemical fuel cells, and hydrogen is under consideration as a non-carbon fuel for internal combustion engines. Transportation also can be decarbonized through initiatives like mass transit trains powered by net zero electricity and cities that reduce automobile use by being more pedestrian and bicycle-friendly. As with most things in life, none of these are perfect and they all have their advantages and disadvantages. Given the potential severity of the climate crisis, however, an “all of the above” strategy for zero carbon vehicles is warranted.

Geoengineering seeks to alter the Earth itself to respond to the climate crisis. Two of the main ideas are to reduce incoming solar radiation by releasing aerosols high in the atmosphere to cool the planet, or to remove the excess greenhouse gas , mainly carbon dioxide, that has built up in the atmosphere over the past two centuries. Aerosols injected into the stratosphere by nature during volcanic eruptions can sometimes produce dramatic cooling effects, such as the “year without a summer” in 1816 following the eruption of Mt. Tambora in Indonesia. Solar radiation management seeks to add anthropogenic aerosols to the stratosphere to overcome the most severe effects of global warming such as massive heat waves. Carbon dioxide removal from the atmosphere can be done using photosynthetic plants, although the amount of available land for planting trees is limited and up to a trillion new trees would be needed to mitigate climate change . A second option is to engineer devices to capture it using various chemical processes and specialized machinery. The captured carbon must be stored or sequestered away from the atmosphere for periods of at least a century and the longer the better. All these options are under consideration by governments, research institutions, and venture capital investors. When combined with an energy switch away from fossil fuels , geoengineering techniques promise a way to mitigate the worst aspects of climate change .

No one can accurately predict the future, but it is almost certain that a century from now we will be using some kind of energy other than fossil fuels. Whether that is high tech, sustainable nuclear and engineered geothermal to supplement wind and solar, or wood fires while the remaining humans hunker down in smoky caves is totally up to us. Many people, especially many young people are in despair about the future. The climate crisis looks insurmountable, and they’ve given up hope. Meanwhile, other people sashay through life carrying on business as usual, never giving the climate a second thought, convinced that it’s not a problem, and even if it is, science can easily solve it. Both extremes are dangerous and delusional, and both have something in common: nothing gets done. In between is the realization that the crisis is real, but the situation is not dire, and there are ways climate can be fixed, even if it won’t be easy. This is the approach where things get done and it is the approach we need. Developed countries must replace fossil fuel with carbon neutral or zero carbon alternatives, and then adapt this technology for use in undeveloped countries. The undeveloped world is facing the worst consequences of climate change, even though their contribution of greenhouse gas is minimal. The developed world, which burned most of the fossil fuel that led to the current climate crisis in the first place owes it to the underdeveloped world to fix the climate and help them avoid making the same mistakes.

One of the main reasons for the climate crisis is that we’ve grown too big for our britches on Mother Earth. The amount of energy humans are using, the greenhouse gas from the fossil fuels we are burning, the materials being mined and manufactured, and the waste we are generating have all become too great for the planet to handle. Infinite growth cannot happen on a finite planet. Humanity has two options if we want to survive as a civilization: either a planned reduction in resource extraction and use known as “degrowth,” or expansion beyond the Earth into space. Degrowth is complex and difficult to implement without crashing economies and requires a major shift in the economic thinking that has driven human civilization over the last several centuries. Expansion into space is also difficult but presents technical challenges that have multiple ancillary benefits if solved. The Apollo moon landing program gave us major advances in electronics, miniaturization, computing, engineered materials, and flight control. Modern space efforts, many driven by private industry, are solving everyday problems of suborbital and orbital flight, landing re-usable boosters, developing new materials, and figuring out how to move fuel, supplies, and people around in space. Making humanity a multi-planetary species, inhabiting the moon and Mars and other parts of the solar system in the future spreads out industry and populations and reduces impacts on any one place. Manufacturing processes that are environmentally risky can be restricted to factories in orbit or on the moon, avoiding damage to ecosystems and the environment. Humanity has reached the limits of Earth. If we want to continue to grow and develop as a species, we have no other option except space.