The ecological transition hinges on ecological structural change, necessitating smart macroeconomic policies. Incorporating ecological considerations into macroeconomic modelling constitutes a pivotal area of inquiry that examines the nexus between environmental sustainability and economic expansion. This article proposes a macroeconomic modelling to establish a foundational analytical framework to address this challenge. Incorporating ecological considerations into macroeconomic modelling constitutes a pivotal area of inquiry that examines the nexus between environmental sustainability and economic expansion. Contributing to the post-Keynesian Ecological Macroeconomics field, this paper proposes an eco-Keynesian cross due to its simplicity and widespreadness for teaching macroeconomics to illustrate the macroeconomic perspective of green targets strategies in a closed economy. Green public and private investments have the potential to enhance output through the multiplier effect and improve environmental efficiency. However, these investments may also induce rebound effects, resulting in a net increase in pollution intensity within the economy. The model underscores the potential trade-off between social and environmental objectives, which an ecological perspective seeks to surmount by advocating for sustainable and inclusive industrial development.