Wikipedia
In engineering, macro-engineering (alternatively known as macroengineering or macro engineering and as mega engineering) is the implementation of extremely large-scale design projects. It can be seen as a branch of civil engineering or structural engineering but just on a very large land area. In particular, macro-engineering is the process of marshaling and managing of resources, technology and public opinion on a large scale to carry out complex tasks that last over a long period.
In contrast to conventional engineering projects, macro-engineering projects (called macro-projects or mega-projects) are multidisciplinary, involving collaboration from all fields of study; they involve not only engineers, but scientists, lawyers, industrialists, soldiers and politicians as well. Macro-projects are usually international; they override political boundaries because most countries lack the social, financial or physical ability to undertake them alone. As a consequence, macro-projects have the power to fundamentally transform its area of focus.
Macro-engineering is an evolving field that is only recently receiving attention. Because we routinely deal with challenges that are multinational in scope, such as global warming and pollution, macro-engineering is emerging as a transcendent solution to worldwide problems. Macro-engineering, or mega-engineering, is distinct from megascale engineering which deals with projects on a planetary or stellar scale. Where macro-engineering is currently practical, mega-scale engineering is still within the domain of speculative fiction.