Kirby Ledvina: Making a Finer-Grain Assessment

Kirby Ledvina: Making a Finer-Grain Assessment

Mark Dwortzan | MIT Joint Program on the Science and Policy of Global Change

While most kids in her Houston neighborhood were ensconced in classrooms, playgrounds, backyards or other child-centered spaces, seven-year-old Kirby Ledvina could often be found at rallies and planning meetings giving short speeches to community activists. Joined at the hip with her mother, a biochemist turned green building consultant, in a quest for a more livable, sustainable city, she spoke out against the expansion of Interstate 10, diesel exhaust particulates and other threats to the environment. One time she even wore a sandwich board showing how many days a year schoolchildren couldn’t go outside to recess due to high ozone levels. Advocating everything from better mass transportation systems to more stringent clean air policies, she would paint a picture of the kind of city she wanted to live in, stressing that the future of her generation was at stake. Her speeches were often followed by standing ovations.

These outings, along with eventual challenges in getting to high school on city buses, put urban design, energy and the environment on Ledvina’s radar screen from an early age. 

“I became interested in how we can get cities to be smarter in their design and energy use,” she recalls. “When I came to MIT, I wanted to study math and economics so I could figure out how to show people the opportunities for cost savings if they adopted more responsible and sustainable technologies and designs.”

Ledvina’s interest in energy and economics—and a passion for “putting numbers to the environment” —led her to participate in the Joint Program as an Undergraduate Research Opportunities Program (UROP) student. Working full-time in the summers and part-time during the academic year since June 2014, she has collaborated with Joint Program Environmental Energy Economist Niven Winchester and Co-Director John Reilly on a two-phase project sponsored by BP to investigate the impact of a global carbon tax on biofuel production using the MIT Economic Projection and Policy Analysis (EPPA) model.

“Kirby has been instrumental in developing a detailed representation of bioenergy in the EPPA model and in the dissemination of results,” says Winchester. “Her contributions to the project include managing and analyzing large datasets, developing new methods to augment the EPPA model, and building new tools to collate and communicate results.”

Applying a Global Carbon Tax

The project’s first phase involved running the EPPA model from 2010 to 2050 to explore six scenarios: a “business as usual” reference policy extending existing climate commitments through 2050; a base policy implementing a global carbon tax set to achieve a production target of 150 exajoules (1018 joules) of bioenergy by 2050; and four variations of the base policy, in which selected parameters are constrained.

“The main thrust of Phase 1 was: In a world where bioenergy was actually significant, which fuels in particular would rise up, and where would they be produced?” says Ledvina.

To address those questions, she processed EPPA output with the GAMS programming language and developed a Python program to control software used to produce more than 900 Sankey diagrams (flow charts in which the width of the arrows is proportional to the amount of biofuel energy produced) showing the magnitude of bioenergy being produced, its source and its final use in 16 EPPA regions and the globe from 2010 to 2050 in 5-year increments.. Some of these diagrams appeared in a groundbreaking paper published by Winchester and Reilly in Energy Economics estimating that under a global carbon price that accounts for deforestation, biofuel and other clean energy technologies could reduce greenhouse gas emissions 52 percent in 2050 relative to the business-as-usual case.

Expanding Irrigation

In Phase 2 the researchers plan to explore where constraints on the expansion of irrigable land may impact the scale of bioenergy production. Toward that end, they’re working to enhance the accuracy of the EPPA model’s projections by distinguishing between irrigated and rain-fed land. This will enable Ledvina and her collaborators to determine the cost of converting rain-fed land to irrigated land, and how that cost affects land use and economic productivity. They will subsequently run a Phase 1 global carbon tax scenario to see how more accurate land-use modeling affects bioenergy production projections, and how imposing additional constraints on irrigated land further impacts the results.  

To support Phase 2, Ledvina developed software to estimate the harvested area of different crops on rain-fed and irrigated land at the country level, and to calculate current crop production values in U.S. dollars. This data was then fed into the EPPA model to enable projections of future crop production values in different subregions of the world, both on irrigated and rain-fed land. Working from data assembled by Joint Program Research Scientist Kenneth Strzepek, she also modelled the costs involved in the regional transformation of rain-fed into irrigated land.

“When we understand at what cost you can transform rain-fed land into irrigated land, we can plug that into EPPA so it will use that cost to project the likely amount of irrigated land in future years, and determine the profitable amount of rain-fed land to convert,” Ledvina explains. “By distinguishing between rain-fed and irrigated land, you get a more accurate idea of how much crop production will result, and thus how much biofuel will be produced.”

Building a Skillset

Now a junior majoring in management science and economics, Ledvina plans to continue supporting the project for the duration of Phase 2, and possibly beyond. Throughout her time as a Joint Program UROP student, she has cultivated skills not only in programming and modeling but also in communicating the results of her work in periodic conference calls with Winchester, Reilly and James Primrose, BP Biofuels Head of Strategy and Market Analytics.

“In our last call, I presented a research update to BP and enjoyed the process of understanding the technical details and communicating them,” says Ledvina. “I like the skills I’m gaining here, and hope to use them in the future.”

Her default plan is to work as a management consultant or analyst focused on energy, the environment or public policy. Regardless of the issues she chooses to tackle, Ledvina aims to organize people to pursue action aimed at improving the quality of life. And stand up for future generations, just as she did back in the old days. Even if she’s still the youngest one in the crowd.

Her default plan is to work as a management consultant or analyst focused on energy, the environment or public policy. Regardless of the issues she chooses to tackle, Ledvina aims to organize people to pursue action aimed at improving the quality of life. And stand up for future generations, just as she did back in the old days. Even if she’s still the youngest one in the crowd.
 

Related Publication:

Winchester, N. and Reilly, J., 2015: The feasibility, costs, and environmental implications of large-scale biomass energy. Energy Economics Vol. 51, September 2015, pp. 188–203. DOI: 10.1016/j.eneco.2015.06.016

This article originally appeared in the Fall 2015 issue of Global Changes.