Well i suppose the most unconventional ways to save the planet would be geoengineering methods. Such as polluting the atmosphere with sulfate aerosols to reflect incoming radiation, in the same way volcanoes do, which could cool the climate temporarily so if people did that continuously then the warming could be kept under control. The problem with this method is there are too many risks involved and some studies have shown it could have side effects like turning off the indian monsoon and even decreasing rain fall in Africa. Other methods with a similar effect would be to place large mirrors in space, artificially create clouds, painting house roofs white etc. All of these would reflect more incoming radiation back into space. Another method would be to fertilise the oceans with Iron which would increase the numbers of plackton and increase the removal of carbon dioxide.
Or using Biochar to sequester carbon and place it in the soils which would remove carbon dioxide from the atmosphere whilst also increasing the productivity of agriculture. I’d say the conventional wisdom on ways to save the planet are for humans to have less of an impact and not more, so these methods would be a continuation of humans directly interfering with nature which is why they’re not popular ideas. They would also only provide a temporary solution whilst society solved the source of the problems, but it may make people less motivated to solve those issues.