Many speculate what would happen to the U. S.’s pledges to curb greenhouse gas emissions after Donald J. Trump takes control of the White House. The U. S. promised not only to cut its own emissions through its Intended Nationally Determined Contribution (INDC) but to help poor countries under the Paris Agreement. Unfortunately, the President-elect has openly vowed to leave this landmark deal, which intends to limit the global temerature increase to 2 degrees Celsius. So, what if the U. S. cannot meet, or even abandon, the INDC? Alternatively, if it somehow manages to deliver its promise, does it mean the worst-case climate scenario averted?
Reducing the national emissions often involves a powerful policy tool such as carbon tax or emission trading. While many focus on the effectiveness of such measures in cutting carbon emissions, there have been some serious discussions on how to spend the money gained from tax or cap-and-trade auctions. We are talking about some BIG money here; for example, California is reaping over $2 million annually from its cap and trade, and the proceeds are expected to grow over time .
Ever since global leaders came to an agreement in Copenhagen that “an increase in global temperature should be below 2 degrees Celsius ” in 2009, there have been heated discussions over whether the so-called 2-degree goal is appropriate, realistic or sufficient as a means of avoiding the worst climate scenario. CNN even set up a “2-degrees series” on its opinion section to thread the goal through energy and climate issues .
Today, countless smokestacks around the world are emitting carbon emissions into the atmosphere. This is not a good news, as “cumulative emissions of hundreds or even thousands of gigatonnes of CO2 would need to be prevented during this century to stabilize the CO2 concentration at 450 to 750 ppmv (IPCC).” Because we cannot just stop using fossil fuels overnight, other ways are pursued to offset the emissions. The idea of carbon capture and storage (CCS) is simple; to capture the emissions from energy-using processes and dispose it. In details, CCS technology includes collecting and concentrating the CO2, transport it to a storage location, and then store it for as long as possible .
One of the hottest environmental issues during the Obama Administration has been the Keystone XL pipeline. In January 2012, President Obama exercised his veto power against the proposed project. The 875-mile long pipeline and related facilities were supposed to transport up to 830,000 barrels per day (bpd) of crude oil from Alberta, Canada and the Bakken Shale Formation in Montana . Once constructed, the pipeline that would go across the entire North America is expected to last for over 50 years.
The matter of energy is unfair from the beginning; some countries have massive amounts of energy resources buried within their territory, while others have to rely most of their energy needs on import. But now with climate change and its impacts applying increasingly higher pressures on humankind’s energy use, another kind of unfairness began to emerge. If the international community is to stabilize the global temperature increase within 2 degrees as proclaimed, countries around the world are compelled to leave much of their fossil fuel reserves unexploited .
Do you think oil is being depleted? If so, you are one of the 76 percent of Americans who answered in 2008 that they believed the world was running out of oil . This belief is in line with Hubbert peak theory, according to which “the rate of production of any particular fossil fuel follows a bell-shaped curve with time (Andrews and Jelley, 2013, Energy Science)”. The theory seemed to be accurate especially in the 1970’s, when the scarcity of crude was highlighted with a series of oil shock events. The rate of oil production was thought to be heading toward a peak; by 1970, global oil production rose to 48 million barrels a day (mbd), a nearly five-fold increase from 10 mbd in 1950. However, as demonstrated in the figure , the historical data became increasingly inconsistent with Hubbert’s prediction as time goes by, particularly since the 2000’s.
At a glance, biofuels seem to be a clean energy source with lower GHG emissions and massive potentials across the world. Plus, they are cost-competitive with fossil fuels. Expansion of the use of biofuels has significantly contributed to rural employment and energy security. However, serious criticism about biofuels and other bioenergy has surfaced in the recent years; for example, in 2011, the science committee of the EU’s environment agency gave a warning that there is an “accounting error” regarding bioenergy, and the consequences would be grave for the Earth’s forests and climate.
In 2013, the team of GreenGT H2 prototype racer, which might have been the first vehicle without a petrol engine to compete in the Le Mans 24-hour race, announced withdrawal from the renowned competition. Even though it took a long time to develop the fuel-cell race car, said the head developer, it is not ready to participate in the tough race. This incident reflects the immaturity that the current fuel cell technology represents. Hailed as a state-of-the-art solution to a greener energy future, the technology with great potentials has yet to be fully exploited.
Fuel cells have a number of advantages—such as very low emission levels and relatively good efficiencies, especially compared to renewables. In addition, they are vibration-free, quiet and reliable. Compared to battery-powered vehicles, the fuel-cell cars can be refueled rapidly just like gasoline-powered cars. Moreover, the rate of self discharge is not an issue compared to average electric cars.
Nonetheless, there are challenges to address, including costs and practical efficiency. Since ‘fuel’ cells are not batteries and thus need constant injection of fuel, fuel supply can involve complicated issues with infrastructure and chemical processes. Safety concerns exist as well, if hydrogen is used as a fuel.
An idea of harnessing fuel cells is to use them in renewable energy system. For example, hydrogen can be used to store intermittent electricity generation by renewable sources such as solar and wind. According to Fuel Cell Today, “excess electricity is fed into an electrolyser to split water into its constituent parts, oxygen and hydrogen. The hydrogen is then used in fuel cells to produce electricity when needed, releasing the stored energy back to the grid.” Considering the benefits of electricity storage, fuel cells can contribute to grid stabilization, protecting consumers from energy price spikes or intermittency of renewables. Furthermore, the stored hydrogen can be used only for grid electricity but sold to fuel-cell car owners as a fuel.
Fortunately, more efforts are being made for newer and more innovative technology. Researchers are discussing fuel cell/ battery hybrids, use of non-hydrogen fuel such as methanol, and harnessing shale gas by-products. At any rate, even if fuel cells are not the cure-all, at least they can contribute to a cleaner energy future.
 Andrews and Jelley, 2013
 Sioshani et al. 2008, Estimating the value of electricity storage in PJM: Arbitrage and some welfare effects
The U.S. hailed the recent discovery and development of shale gas, as the primary factor for a cleaner and more secure energy landscape. Natural gas is often thought to be a ‘bridge fuel’ between fossil fuels and renewables, even though it falls into the former category. It is indeed a ‘cleaner’ energy source, especially compared to coal; its carbon dioxide emissions are just 45% of those of coal (Andrews and Jelley, 2013). According to the EPA, natural gas emits one third as much nitrogen oxides as coal. In addition, a lifecycle analysis found that “existing domestic coal power plants produce two and a half times more emissions than that of LNG.” In other word, even the cleanest coal technologies were found to produce 70% more lifecycle emissions than LNG.
Natural gas is one of the cheaper energy sources too. The production level has been hiking with shale gas (see the figure below), and the upward trend is expected to continue in the coming decades. Owing to this abundance, natural gas has become the cheapest source of electrical power in the U.S. market, priced at an average of 6 cents per kilowatt hour, vs 9 cents for coal and hydroelectric and 11 cents for solar. Other advantages include its versatility and easy transport; natural gas can be used for residential and industrial uses, and it can be stored or carried relatively easily using pipelines, tankers and other units.
Nevertheless, there is no light without darkness. One of the primary concerns about natural gas, particularly regarding the unconventional sources, is hydraulic fracturing, also known as fracking. The natural gas extraction method can cause, albeit arguably, serious threats on the environment and human health by triggering seismic instability and contaminating underground water sources. Moreover, some say natural gas is actually as harmful in terms of greenhouse gas emissions as coal, if we consider potential methane leaks. Methane, the main component of natural gas, has “a more potent short-term effect on climate change than carbon dioxide”. The chain of pipelines and equipment required to produce and transport natural gas emits an extensive amount of methane, which dilutes the fuel’s less substantial CO2 emissions.
Perhaps the most important point is that relying on natural gas can be an easy alternative to using more renewables, thereby delaying a transition toward a cleaner energy future. Steven Davis, a professor at UC Irvine, made an interesting comment: “cutting greenhouse gas emissions by burning natural gas is like dieting by eating reduced-fat cookies. It may be better than eating full-fat cookies, but if you really want to lose weight, you probably need to avoid cookies altogether.” If people treat natural gas as a non-fossil fuel, the bridge is likely to become a block.
 Source: New York Times, retrieved from http://www.nytimes.com/2015/08/19/science/methane-leaks-in-natural-gas-supply-chain-far-exceed-estimates-study-says.html?_r=0
 Source: EIA, retrieved from http://www.eia.gov/forecasts/aeo/electricity_generation.cfm
 Image source: Center for Liquified Natural Gas (CLNG)