Today's complex climate models aren't equivalent to reality | Aeon Essays

"Today's complex climate models aren't equivalent to reality. In fact, computer models of Earth are very different to reality - particularly on regional, national and local scales. They don't represent many aspects of the physical processes that we know are important for climate change, which means we can't rely on them to provide detailed local predictions. This is a concern because human-induced climate change is all about our understanding of the future."

"This understanding empowers us. It enables us to make informed decisions by telling us about the consequences of our actions. It helps us consider what the future will be like if we act strongly to reduce greenhouse gas emissions, if we act only half-heartedly, or if we take no action at all. Such information enables us to assess the level of investment that we believe is worthwhile as individuals, communities and nations."

"For many of us, these issues are approached through the lens of personal experience and personal cares: we want to know what changes to expect where we live, in the places we know, and in the regions where we have our roots. We want local climate predictions - predictions conditioned on the choices that our societies make. So, where do we get them? Well, nowadays most of these predictions originate from complicated computer models of the climate system - so-called Earth System Models (ESMs)."

Earth System Models (ESMs) are widely used for climate predictions but are not equivalent to reality, especially at regional, national, and local scales. Many important physical processes are not represented, preventing confident detailed local forecasts. Reliable future climate understanding requires more than historical observations because rising greenhouse gases drive the system into unprecedented states. Climate information enables informed decisions about emission pathways and investment priorities across health, education, security, and culture. Individuals and communities prioritize local impacts and conditional predictions tied to societal choices. Most contemporary local projections originate from complex ESMs despite their structural and process limitations.

Read at Aeon