The following sources of energy are all non-polluting. This, together with the adoption of non-polluting nano/bio-technologies has reduced the human effect on global climate to almost nothing.
Almost all the energy used on Earth is collected by orbital solar power platforms. These convert incident light into electrical energy using vast sheets of nanobuilt solar cells. The energy is transmitted to Earth in the form of microwave beams which are collected by rectenna arrays in sparsely populated regions, or via superconducting wires in a beanstalk.
Mobile power sources are usually fuel cells or magnetohydrodynamic (MHD) turbines, both of which are powered by hydrogen produced by geneered algae on desert hydrogen farms.
Larger power sources, mostly for large spacecraft, ships and submarines, are generally muon-catalysed cool fusion reactors.
There has recently been great interest in the possibility of using hydrogen/antihydrogen reactions for powering spacecraft, but the limited availability of antimatter has restricted the use of such rockets to uncrewed experimental vehicles.
The future of Ad Astra