The Use and Limits of Science in Making Ethical Decisions

The Proper Use of Science in Determining Risk Assessment

[2] Risk assessment is one way of making decisions about whether or not a new technological advancement is worth the price to the environment, but this often requires having some knowledge of the future consequences in order to assess the risk. Determining future consequences can be difficult when the system is complex. Often, we have to make decisions with incomplete scientific knowledge. In these situations, we can be aided by “the precautionary principle,” which states that we should err on the side of safeguarding the environment for other species when we don’t have full scientific knowledge of the situation.[1]

[3] Decision making requires looking at as much evidence as possible while acknowledging that there is not total scientific knowledge about the situation and applying the precautionary principle in situations when knowledge is incomplete. In order to understand our planet and the environment, scientists use computer simulations to model complex and nonlinear systems. These simulations are becoming more accurate with increasing computer capabilities. But, of course, all computer simulations have limitations, and these limitations need to be taken into account when using computer simulations for decision making. Computer simulations will be the central focus of the rest of this paper on using science for making ethical decisions.

[4] Computer simulations have played a major role in determining causes of climate change and in predicting future climate impacts. The use of computer simulations has been used by the scientific community to investigate the impact of greenhouse gases on the role of climate change. The Intergovernmental Panel on Climate Change (IPCC) issues reports based on these models and simulations.

[5] The United Nations Environmental Programme issues an annual emissions gap report based on these climate simulations. These reports use computer simulations to bound the emissions needed to limit global mean temperature increase. The reports also discuss mitigation strategies that could allow us to reach these emission limits including government fiscal changes and innovation strategies.[2] These reports can be used by policy makers to make decisions on economic policy such as carbon taxes and innovation policy to make informed and least costly decisions for the country.

[6] Since the results of computer simulations are important for decision making about climate change, there is a responsibility to discuss the accuracy and known limitations of these simulations. Climate simulations model the entire planet over large time scales. By their nature computer simulations are simplifications of the physical universe. Climate simulations rely on mathematical equations to compute future states of the climate. Due to the complexity of the system and limitations of computer resources, these equations often need to be simplified to run the simulations in a reasonable time limit. Computer simulations need to be put on both spatial and temporal grids that limit the resolution of the simulations. Some processes like clouds have conceptual models that are used in climate simulations. Cloud processes cannot be included on the larger spatial and temporal grid of climate simulations so the cloud processes are parameterized in the simulation. Another example of a conceptual model is the impact of vegetation. The impact of vegetation is too complex to simulate in a climate simulation so a conceptual model is created to include some effects in the simulation.[3]

[7] In order to estimate the accuracy of the computer simulations, these computer simulations are compared to data. In addition, the computer simulations can be compared to other models for consistency. There are climate simulations from across the world that IPCC uses to make conclusions about the climate. Some of these simulations give independent results. Results from multiple simulations can be combined to remove some biases from specific simulations.[4] The IPCC over the years have issued reports on these models with confidence levels for their conclusions.[5]  These reports include validation reports based on past climate data. The evidence show that the computer simulations are improving.[6]

[8] Showing the improvement of the computer simulations with the public can build trust in the science behind climate change. Building trust with the public also means sharing the limitations of knowledge and climate simulations. For example, clouds are a challenge in climate simulations and the IPCC states “There is very high confidence that uncertainties in cloud processes explain much of the spread in modelled climate sensitivity.”[7] By explaining the processes that account for variation in results in the climate models, the IPCC can build trust with the public that simulations are well-grounded in known science and that scientists understand the limits of their simulation results.

Using Risk Assessment to Make Ethical Decisions

[9] Dealing with climate change means making economic changes that will impact our lives.  Computer simulations can help set emissions goals that drive economic and innovation policy. If the results from these computer simulations along with their known limitations and assumptions are not communicated to the public, there can be resistance to policy changes. The IPCC is a role model in issuing reports on climate change including the status of the models along with the verification of the computer simulations. While the IPCC reports are a model for using computer simulations and communicating their results to the public, they are not often cited in detail in policy debates about climate change in political discussions. The gap emissions reports by the United Nations Environment Programme are good models of communicating policy examples based on results from computer simulations.

[10] In Ethics of Hope, Jürgen Moltmann states that “Every theology starts with the assumption that neither the human being nor nature is centre of the world, the centre is God, and the world is his creation.”[8] In Genesis, God created and is in covenant with not only humans but with all of creation. God said to Noah “As for me, I am establishing my covenant with you and your descendants after you, and with every living creature that is with you” (Gen 9:9-10). Humans were made in God’s image and were placed in dominion of creation (Gen 1:26) to exercise dominion not for human gain but to exercise our dominion as people made in the image of God to model God’s love for the entire community of creation. In the second creation story, “The Lord God took the man and put him in the garden of Eden to till it and keep it” (Gen 2:15). Moltmann states, “In a creation covenant like this, it is a matter of balancing out the different concerns in common responsibility before God.”[9]

 [11] The ethical use of science comes with understanding the limits of scientific knowledge and humans viewing themselves as part of God’s creation community with God at the center not humans. Congregations can play a role in advocacy for a creation covenant. We need to bring to the decision-making process a humility that recognizes that these are difficult decisions that are being made with incomplete knowledge. To do advocacy responsibly, our advocacy has to be based on the best science available at the time and also being humble enough to realize that we will never have complete scientific knowledge to completely manage risk. Decisions will need to made not on certainty but based on probabilities and this calls us to consider the precautionary principle when making decisions. In the absence of complete knowledge, our actions should be based on acting with the least harm to the environment as best as we can determine.

[12] Congregations can aid in this responsibility for making the best decisions by making the effort to learn the science and communicating these results to their members. This can be done using scientists in their congregations to aid in communicating the results from publications such as the IPCC to their members in a slightly more digestible form. In addition, congregations can model the creation covenant by making good environmental decisions in their daily practices. Even if they seem like small gestures, actions speak louder than words. Christians need by both words and deeds act in ways consistent with God’s covenant with creation.



[1] Timothy O’Riordan and James Cameron, “The History and Contemporary Significance of the Precautionary Principle” in Interpreting the Precautionary Principle, ed. Timothy O’Riordan and James Cameron (New York: Earthscan, 1994)  16-17.


[2] UN Environment, “Emissions Gap Report.” (accessed December 29, 2019).


[3] Gregory Flato and Jochem Marotzke, “Evaluation of Climate Models.” (accessed December 29, 2019) 749.


[4] Ibid., 746, 755.


[5] Ibid., 743-744.


[6] Ibid., 824-825.


[7] Ibid., 743.


[8] Jürgen Moltmann, Ethics of Hope, trans. Margaret Kohl, (Minneapolis: Fortress, 2012) 142.


[9] Ibid., 143.

Kristi Keller

Kristi Keller is a student at United Lutheran Seminary and serves in Lutheran Alliance for Faith, Science and Technology.  She has a Ph.D. in Physics specializing in simulations of the Earth’s magnetosphere.