There’s a big difference between supporting food security and subsidising otherwise unviable land usage and farming practices. In the UK, there are subsidies for upland farming for sheep with produces a negligible amount of food at high cost (monetary and environmental) for next to no return for the farmers even after the subsidy.

Re. green subsidies that is better characterised as investment in technology of the future. You might also like to compare subsidies to the fossil fuel sector as well.