The present work explores the use of interval extensions to reduce the carbon footprint of computer simulation. We present a method for estimating the amount of energy expended based on the number of operations performed and we demonstrate how different numerical representations of the same system can lead to a considerable reduction in the number of operations and, consequently, energy consumption. We have applied our technique on three scenarios for discrete simulation of the well-known Chua's circuit. The results show a saving of approximately 22.50% in the values of emitted CO2 and consumed energy when using two different forms of representation of the same system. A simple rewrite of a differential equation could lead to a decrease in the number of operations, mainly the number of multiplications adopted in the representation of Chua's circuit, resulting in reliable and more efficient simulations.