Happy Friday everyone, and welcome back to another edition of the ClimateRoots newsletter. In today's issue, you'll be hearing from our featured writer, Alessandro Mauceri on his ongoing PhD research into the paleoclimate of South America. Next, be sure to read all our headlines this issue as these past weeks have been a doozy!  Wrapping up the issue this week is an introduction to yet another form of renewable energy: Hydroelectricity!

Alessandro in Minnesota going over the unique geology of the region / Image courtesy of Alessandro Mauceri

Featured Writer - Alessandro Mauceri

Alessandro Antúnez de Mayolo Mauceri is a second year PhD student at Washington University in St. Louis studying past and present climate change in the South American tropics. His research integrates stable isotope and organic geochemistry to explore how Quaternary (the last 2.6 million years) changes in climate affect rainfall and ecosystems in the Brazilian Amazon and Colombian Andes. Alessandro is also passionate about making the geosciences accessible to traditionally underrepresented communities. Before his time at Washington University, Alessandro received his bachelors in geology from Macalester College in 2020.

In today's issue, Alessandro will be sharing an overview of his paleoclimate research, which focus' on the South America tropics. Within his piece, he gives a great overview of what paleoclimate is and how it works. More importantly, he dives into why exactly we study it (specifically why South America) and how having an idea of our Earth's past climate can influence its future climate. Click below to read the piece on our blog.

Interested in being a Featured Writer? Fill out this survey and let us know!

Weekly Headlines

Extreme ‘Bomb Cyclone’ Dumps Over 5 Inches of Rain Overnight on San Francisco (Associated Press, NBC, Axios, San Francisco Chronicle, Boston Globe)

• Torrential rains in California surpassed 5 inches in a 24 hour period last weekend, which is the most in that amount of time since record keeping began in 1877.

• The storm comes on the back of an extremely intensive fire season, triggering flash floods and mudslides throughout the region due to the precipitous state of vegetation.

• A ‘bomb cyclone’ is a non tropical storm in which the pressure drops by 24 mb in 24 hours; in this case it more than doubled that rate.

• Less than a week later and on the other side of the country, much of New England was hit with a ‘bomb cyclone’ of its own which triggered floods, felled trees and caused hundreds of thousands to lose power.

Carbon Dioxide Levels Rise Following Pandemic Dip, Pushing Emissions Back to 2019 Levels (New York Times, InsideClimate News)

• Following the shutdown of the global economy due to Covid-19, CO2 emissions from fossil fuels decreased about 5.4% relative to 2019 emissions. Data from the Global Carbon Project, shows that CO2 emissions are set to rebound to their 2019 levels in 2021, with a 4.9% increase in global emissions relative to 2020.

• A key factor is the increase in CO2 emissions from India and China. Both countries have increased their emissions by 4.4% and 5.4% relative to 2019 levels. This is largely attributed to increased use of coal to produce electricity in both countries.

Hertz Inks Deal with Tesla to Purchase 100,000 Teslas (Axios, NPR, CNBC, ABC)

• Hertz will be adding 100,000 Tesla Model 3s by the end of 2022 to its fleet. No price has been given but at $40,000 a piece, the deal would be worth roughly $4 billion.

• The company plans to partner with the GOAT (aka Tom Brady) to help promote its new EV push.

• Following the deal, Tesla stock soared to over $1 Trillion for the first time following excitement over both the guaranteed revenue and the potential marketing opportunity for the car manufacturer.

House Oversight Committee Declares Subpoenas for Big Oil (Heated, Reuters, CNN, Gizmodo)

• After a six hour hearing between the house oversight committee and in which many big players from the oil and gas industry did their best to reveal very little (including the Exxon, Chevron, Shell and BP CEOs), Rep. Carolyn Maloney announced that she was issuing a subpoena to the oil and gas giants.

• The hearing, and subsequent subpoena, aims to investigate big oil’s past and present efforts to halt climate action through targeted funding and the spread of climate misinformation.

• During the hearing, many republicans actually apologized to the CEO’s despite the well known fact that new fossil fuel exploration needs to stop next year and emissions must drop greatly in the next decade.

To read more headlines from this week, click below.

Industrial smoke in New York/ Image Courtesy of Wix

Hydropower 101

Hi everyone! 

In today's issue we are going over the basics of hydroelectricity, a form of renewable energy that creates electricity by harnessing the power of moving water (aka hydropower). Humans have been utilizing hydropower since the first grain mills were placed along river banks, making it one of the oldest renewable energy sources. Hydroelectricity became an energy commodity in 1882 with the opening of the first hydroelectric energy plant selling electricity in Appleton, Wisconsin. According to the U.S. Energy Information Administration, “In 2020, total U.S. conventional hydroelectricity generation was about 291 billion kilowatt-hours (kWh), equal to about 7.3% of total U.S. utility-scale electricity generation,” (Where Hydropower Is Generated - U.S. Energy Information Administration (EIA)). At just over 7%,  hydropower is one of the most used renewable sources, right below wind energy, which produces about 8% (“Renewable Energy”).

The amount of power that can be harnessed by a hydroelectric plant is dependent on two major factors: the volume of water that is moving through the plant, as well as the elevation change of the water before and after entering the plant (“How Hydropower Works”). While many of us associate hydroelectricity with dams, there are actually three different forms of hydroelectric power plants; impoundment, diversion, and pumped storage plants. 

Impoundment Plants: 

Impoundment plants are the most common type of hydroelectric power plant in the United States. By using a dam to store river water in a reservoir, the plant will release this water that it flows through a turbine which powers a generator to produce electricity (“Types of Hydropower Plants”). Because the water is held in a reservoir, it can be released selectively to accommodate electricity needs (which is not possible with wind or solar) or to respond to environmental pressures (like flooding or wildlife passage). Power lines connected to the generator connect this electricity to the power grid and distribute it to our homes and businesses (Hydroelectric Power: How It Works)!

Diversion Plants:

A diversion plant diverts a river from its natural course to channel it toward a generator producing electricity (Society). A diversion plant does not require a dam, but instead utilizes a “penstock”, which is a pipe that moves the water down a natural decline in a river bed towards the generator (“Types of Hydropower Plants”). Once the water has moved through the generator, it is able to rejoin the natural flow of the river. 

Pumped Storage Plants:

Pumped storage plants can best be thought of as a water battery (cool, right?).  During off-peak times in the grid, excess power can be used to pump water uphill from a lower reservoir to a higher one. This is generally in the middle of the night when energy demand (and cost) is at its lowest. While there is some loss in the process from pump inefficiencies (as well as a small amount of evaporation), essentially all the power that was used to pump the water uphill is “stored” in the upper reservoir via the potential energy of the now elevated water. During peak hours when a supplement of power is needed, the higher reservoir can be opened up, and all the water will run back downhill through a turbine generator, thus adding all the power back into the system! This form of power production is amazing for short term, high load periods - think middle of a hot summer day in Georgia when everybody needs their A/C. However, the energy used to pump the water back uphill is taken from the energy grid, meaning that there is no guarantee that this power is renewable in and of itself.

While it may not be the first thing you think about when the topic of renewable energy comes up, hydropower is one of the most versatile and long standing forms of power generation in the modern world. Renewable energy isn’t perfect, and hydropower is no exception. But with high efficiencies and existing infrastructure, hydropower can be some of the cleanest renewable energy we can get today. However, interrupting the natural flow of water has always been a point of controversy, especially as we start to experience worse and worse drought conditions each year. Check back next issue as we dive into what makes hydropower so controversial!
 

To read this full piece with works cited, check it out on our blog!

Hydroelectric Plant  / Image Courtesy of  Wix

Missed our last issue? Want to start from the beginning? No worries! Click below to catch up on all our newsletters.