Climate models are everywhere. They appear in IPCC reports, policy debates, media headlines and activist arguments. They project temperature pathways, estimate carbon budgets, simulate extreme events and calculate the costs of inaction. And yet, they are also a frequent target of scepticism, misunderstanding and political frustration.
Some critics dismiss them as “just models.” Others expect them to deliver certainty, prediction and behavioural change and are disappointed when they don’t. Both reactions miss the point. To understand the role of climate models, we need to be clear about what models are, what kind of knowledge they produce, and how they are meant to inform democratic decision-making in a world of deep uncertainty.
Models are tools for thinking, not mirrors of reality
At their core, models are simplifications. They do not reproduce the world as it is; they represent selected aspects of reality for specific purposes. Philosophers of science such as Axel Gelfert and Margaret Morrison describe models as mediating instruments between theory and observation: neither pure abstraction nor direct description, but tools that allow us to reason about complex systems we cannot experiment on directly.
A top view on the world. Models help us see what we are looking for.
This is especially true for climate science. The Earth system is not a laboratory. We cannot rerun the 20th century with and without fossil fuels to see what happens. Climate models therefore do something more modest and more powerful: they explore conditional futures. They answer questions of the form: If emissions follow this pathway, what range of outcomes becomes likely? Seen this way, models do not claim certainty. They structure uncertainty.
What comes next:
In part 2 of our series on climate models, we take a closer look at what we actually mean by “climate models” and why climate modelling is best understood as a diverse family of models whose strength lies in their plurality.
About KNOWING
KNOWING is a Horizon Europe project that develops tools, models and participatory formats to support climate-transformation. By combining scientific analysis with local knowledge and stakeholder input, the project supports regions and sectors to understand climate risks, assess options, and design effective, inclusive pathways for change.