Climate change may eventually change for instance global cloud heights. Photo:NASA

The UN Global Goals for Sustainable Development state that immediate action needs to be taken in order to reduce the human impact on the climate and climatic changes. But at the same time as this is urgent there are big uncertainties in the details of how much and how fast the climate is changing.

Researchers have trouble with giving a number for the so called climate sensitivity. Climate sensitivity is a way to measure how the average temperature on earth is expected to rise due to doubled carbon dioxide emissions in the atmosphere.

− These uncertainties of course affect decision makers. Implementation of the Paris agreement goals, or any temperature goal, is highly dependent on uncertainty in climate model projections of future changes. And this is closely related to the uncertainty in climate sensitivity. Action on a temperature goal relies on knowledge of how much temperature increase a given amount of CO2 emissions will result in. If the climate sensitivity is high, action needs to be even more drastic than if it is lower, says Frida Bender at the Department of Meteorology at Stockholm University.

Frida Bender

When the UN Climate Panel IPCC summarize different climate research studies they give an estimated percentage in which the climate sensitivity is expected to be. The estimations are based on several uncertainties.

− In this project we ask how come these estimates have not changed over the last decades. We want to look at how researchers are affected by their role as knowledge mediators to society and decision makers. Climate models are complex systems and behind every process-description and experiment there are choices. Choices on methods, models and parameters in the research can not be disconnected from ethical and social values, in this sense all research is affected by values.

Climate research affected by values

When it comes to climate research it is especially interesting to study how these values affect the scientific process. There is a strong connection between climate research and big and important societal questions.

− The large uncertainty in climate sensitivity motivates the climate science community to continue to evaluate and improve climate models, and refine projections of future climate. In doing so, many scientists are unaware that the research process at many levels is influenced by social and ethical values. Values influence choices of problems to study, results to publish, models and parameter ranges to use. Not least ways to present and communicate results and their related uncertainty, says Frida Bender.

This is why this new project is interdisciplinary. The aim is to look at uncertainties in climate projections from two different angles. On the physical science side, climate model simulations will be performed that challenge the current understanding of aerosol-cloud interactions, which are at the heart of the uncertainty in climate sensitivity.

On the philosophical science side, this scientific process will be followed, and the influence of values on it closely examined.

− We expect mutual benefit for the two disciplines to be achieved. A final joint outcome of the project will be an outline of recommendations for communication of uncertainty and decision making based on uncertain information.