• Dr. Lee Anne Willson

By the Numbers

Updated: Feb 24

Examining issues related to the Ames Climate Action Plan:


Some years ago, while teaching astronomy at ISU, I asked my class a question: If there is a one-in-a-million chance that a killer asteroid will hit and wipe out advanced life on Earth in your lifetime, what should we do about it? Most of the class divided into two extremes: (a) Ignore it; or (b) Do everything we can to stop it from happening. This is an illustration of how people often react to new and unfamiliar risks: Either by setting it aside as irrelevant or too scary to think about, or by focusing all their attention on avoiding the risk. We saw this happening with the COVID19 pandemic – some people refused to change what they were doing, and some people locked themselves at home for the duration.

When I am faced with an unfamiliar risk, my response is to try to understand it, and that often means that I want a quantitative handle on it – I want to get and understand the numbers. This was my approach to the pandemic, and there I had the help of friends and family with expertise in epidemiology to make sure I did understand the numbers correctly. Eventually I shared some of my analyses with people via Facebook – on my account and through Ames People – and from the feedback I received, others found these analyses helpful.

There is a slower-moving but also potentially more destructive risk heading our way, and that is the effect of adding CO2 and other greenhouse gases to our atmosphere, leading to an acidic ocean, climate change, and global warming. When it comes to this risk, I am able to use the background from my professional studies, where I studied the atmospheres of stars and planets. Courses that I taught covered a lot of the basic science behind the greenhouse effect and the methods used to predict its effects – radiative transfer, condensation of liquids or solids from a gas, and hydrodynamics.

What is new for me is understanding how the choices are made that have brought us to where we are now, and how we might get to a better future. Humans have been altering the surface of the Earth since the beginning of agriculture, and perhaps even before by hunting some species to extinction. With the rapid increase in the use of fossil fuels that began in the 1800s, we are having an unprecedented impact on our atmosphere, and we are now seeing the consequences in floods, fires, and storms. The big question is: What can we do to keep this process from going so far that it endangers or ends the civilization we have?

While it is obvious that some changes need to happen as the result of decisions by huge entities – multi-national agreements, national governments, international corporations – many of the decisions that are relevant are made on a local level. Cities and counties are the entities that decide on building codes, on zoning, on local transportation options, and sometimes on what options are available for electricity and natural gas.

I like to say that we are not looking for one solution, but for one hundred 1% solutions. Some of these will be best approached at the local level, and which of these are most appropriate will depend on where you are located. There are interesting opportunities that are appropriate for coastal communities – tidal power, seaweed cultivation – that won’t work in Iowa. However, in Iowa we have the potential to contribute through modified agricultural practices that capture carbon, and we already have a substantial investment in wind power.

Many potential solutions fail if you ask: Can this solve the problem (by itself)? But many of the same are not only possible, but even beneficial, when the question becomes: Can this provide 1% of the solution? One example is planting trees to absorb CO2; if this were to be the 100% solution, too much land that is already in use for agriculture would have to be diverted, or trees planted where they do not naturally thrive. Inevitably, some of the trees would be at high risk of destruction by fire. But when tree-planting is a 1% solution it can lead to benefits in terms of shade cooling and curb appeal for a city like Ames.

In the posts that I am sharing here, my goal is to present and clarify some of the information that goes into deciding how Ames will approach this issue, with a focus on the numbers and an understanding of how models are used in science. The City of Ames has hired consultants, Sustainability Solutions Group (SSG), to advise the city and to translate what the city wants to accomplish – a goal – into a plan, a series of actions to be carried out to achieve that goal. To start the process, the City commissioned three reports from another consultant, Pale Blue Dot (PBD): A greenhouse gas inventory, a vulnerability study, and a study of the potential for solar power for Ames. These are available to download or read on the City’s Climate Action Plan web site: https://www.cityofames.org/living/sustainability-in-ames/climate-action-plan.

I believe we have the tools to solve the climate crisis. It is possible. It will take many individuals, blocks, neighborhoods, towns, cities, counties, states and countries making decisions and taking actions that decrease emissions, increase sequestration, and provide means of adapting to what cannot be avoided. If we are not distracted by “Whose fault is it?” or “It will mean unacceptable changes” or “It is inevitable,” we can do it – the technology is there, and it is affordable, often more affordable than the alternative. But we need to understand the problem, and we need to commit to taking action appropriate to who we are and what we are able to do.