Image description

CLIMATE change stands as one of the most pressing global challenges of the twenty-first century, with its impacts reverberating through both the natural environment and human societies. To understand, predict and potentially mitigate these impacts, scientists depend heavily on climate models. At the very core of these models lies mathematics, an indispensable tool for quantitatively describing natural systems, analysing complex data and forecasting future scenarios. Without mathematics, climate modelling would be impossible. It serves not merely as an abstract language of science but as a rigorous framework through which the Earth’s climate processes are understood and interpreted.

A climate model comprises a collection of mathematical equations that simulate interactions among the Earth’s climate components, including the atmosphere, oceans, land surfaces and ice sheets. These models are grounded in the fundamental laws of physics — thermodynamics, fluid dynamics and radiative transfer — all of which are expressed mathematically. At its essence, a climate model is a mathematical representation of the Earth’s climate system. It enables scientists to reconstruct past climatic conditions, examine ongoing changes and predict what the climate may look like in years to come.


The role of mathematics in climate modelling is both foundational and multifaceted. At the heart of this framework lie partial differential equations, or PDEs, which describe the continuous changes in heat, moisture, pressure and momentum across the atmosphere and oceans. These equations translate Newton’s laws of motion, the conservation of mass and the conservation of energy into mathematical language. In practice, the movement of air masses, variations in temperature and the distribution of atmospheric moisture are all captured through these equations.

Several key mathematical formulations shape the modelling process. The Navier–Stokes equations, for example, describe the motion of fluids and are essential for simulating wind speeds, ocean currents and general atmospheric and oceanic flows. Thermodynamic equations are used to model heat transfer and energy exchanges, thereby explaining changes in atmospheric and oceanic temperature and humidity. Radiative transfer equations govern the absorption, reflection and emission of solar and terrestrial radiation, which are central to understanding the greenhouse effect and Earth’s energy balance. The continuity equation ensures the conservation of air and water mass across the climate system.

Given the extreme complexity of these equations, solving them analytically is unfeasible. Scientists instead use numerical methods to obtain approximate solutions by discretising the equations and solving them at specific points in space and time. These methods — such as finite difference, finite element and spectral methods — divide the Earth into a vast network of grid cells. The smaller and more numerous these cells, the higher the resolution of the model and, correspondingly, the greater its accuracy. Each cell becomes a computational unit through which the broader climate system is simulated.

Beyond equation solving, mathematics also plays a critical role in processing and interpreting the enormous volumes of climate data. Variables such as temperature, precipitation, sea level and carbon dioxide concentration are measured and analysed using statistical techniques. Statistical modelling, for instance, helps to identify long-term trends within historical data and supports projections about future developments. Regression analysis is one such tool, used to track the rise in global temperatures over the past century.

Uncertainty is a persistent feature of climate projections and mathematics provides the means to quantify and manage it. Techniques such as Monte Carlo simulations are employed to estimate the range and likelihood of different outcomes. These methods help identify the sources of uncertainty, whether due to incomplete data, simplified assumptions within the model, or ambiguity about future greenhouse gas emissions. Validation is another key aspect, involving statistical tests to compare model outputs with historical observations, thereby gauging how accurately the models represent reality.

The scale and intensity of the mathematical calculations involved in climate modelling necessitate the use of high-performance computing. Some of the world’s most powerful supercomputers are dedicated to this task, solving thousands of simultaneous equations in parallel. This computational power allows researchers to simulate centuries’ worth of climate data in a matter of days, thereby facilitating long-term projections and policy planning.

Climate models vary in complexity. General Circulation Models, or GCMs, are among the most advanced, simulating the large-scale movements of air and water in the atmosphere and oceans. Earth System Models extend this framework to include biological and chemical processes, such as the carbon and methane cycles, and their interactions with climate systems. On a more local scale, Regional Climate Models provide high-resolution simulations for specific geographic areas, taking into account regional features like topography and coastlines. Simpler models, meanwhile, are used for rapid assessments or to evaluate the impact of specific policies, particularly with regard to greenhouse gas emissions.

Despite the sophistication of current models, climate modelling remains fraught with challenges, each of which underscores the importance of mathematics. Uncertainty, as already discussed, is a constant factor. Mathematical tools are essential for not only quantifying these uncertainties but also refining the models to reduce them. One significant issue is the problem of scale. The climate system encompasses processes at vastly different scales, from microscopic cloud particles to planetary-scale ocean currents. Accurately representing these within a single model demands techniques such as parameterisation, whereby smaller-scale phenomena are expressed in terms of their average effects over larger areas.

Computational limitations present another challenge. More accurate models require finer spatial and temporal resolution, which in turn demands greater computational resources. Mathematical innovations, such as parallel processing algorithms and optimisation techniques, are continually being developed to address these constraints. There is also the persistent problem of data scarcity, particularly in less-monitored regions or historical periods. Mathematics offers methods such as data assimilation and imputation to fill these gaps, allowing models to function even with incomplete inputs.

Climate change is not a problem that can be addressed through politics or policy alone, it is a scientific challenge of immense scale and complexity. Climate modelling is not merely enhanced by mathematics; it is fundamentally dependent upon it. Mathematics provides the language, tools and framework through which natural processes are described, data is analysed and future scenarios are forecasted. In the ongoing struggle against climate change, advances in mathematical modelling will be pivotal. With more precise simulations and better forecasting tools, scientists will be able to understand the consequences of current emissions, anticipate tipping points, and design more effective mitigation strategies.

In this way, mathematics is not just a domain of abstract reasoning. It is one of humanity’s most powerful instruments in confronting one of its greatest existential threats. In the hands of climate scientists, mathematicians and policy-makers working together, it becomes a vehicle for foresight, preparedness and ultimately, resilience.

Ìý

Sadia Sultana Rimi is a student of mathematics at Jagannath University.