EVOLUTION OF CLIMATE MODELS

Climate models combine physics, mathematics and computing to simulate the Earth's atmosphere, oceans and land systems and forecast future climate trends

- KRISHNA GUPTA

In this series on Climate Change, we briefly discussed climate models such as General Climate Models (GCMs) and Earth System Models (ESMs) in earlier articles. There is, in fact, a hierarchy of such models depending on their complexity and their coverage. In this two-part article, we will look at a variety of climate models. In Part 1, we will examine the evolution of climate models and introduce basic climate models.

CLIMATE MODELS: AN INTRODUCTION

There are various climate models that range from simple Energy Balance Models to complex Earth System Models. While simple models take a slice of the whole picture and describe a part of the climate system, complex models such as Earth System Models take the entire climate system into account, including the oceans, atmosphere, land, ice sheets and the carbon cycle.

More generally, a climate model is a representation of the climate system, which consists of the atmosphere, oceans, land (forests and vegetation) and ice sheets. These are expressed in mathematical equations based on the laws of physics, such as the conservation of energy, momentum and mass, the laws of thermodynamics, and Newton's second law of motion. These climate models, consisting of simultaneous equations, are run as iterative computer programs and help us make climate projections.