As a senior programmer working in finance, I would imagine you have quite a bit of savings. I would suggest taking some time away from work to learn something other than programming. I don’t think software is the biggest lever to pull in “climate tech.” These are problems of atoms, not really problems of bits.
However, if you are constrained such that you need to stay primarily in the software domain, I would recommend a lateral into something like a controls or optimization oriented roll. There are plenty of commercial and industrial buildings whose HVAC could operate more efficiently. There are plenty of ISOs and utilities who employ planners and forecasters (and this could be high leverage, as if we solve present day tasks like building lots of clean generation and storage, we will quickly find that transmission and distribution are the new constraints). You will see a lot of companies that are solving issues around measuring, dashboarding, and reporting, but I do not think this is high value work and I think the space is too crowded already, so I would very much recommend you find something where you are directly optimizing the deployment or operation of real physical assets.
However, if you are constrained such that you need to stay primarily in the software domain, I would recommend a lateral into something like a controls or optimization oriented roll. There are plenty of commercial and industrial buildings whose HVAC could operate more efficiently. There are plenty of ISOs and utilities who employ planners and forecasters (and this could be high leverage, as if we solve present day tasks like building lots of clean generation and storage, we will quickly find that transmission and distribution are the new constraints). You will see a lot of companies that are solving issues around measuring, dashboarding, and reporting, but I do not think this is high value work and I think the space is too crowded already, so I would very much recommend you find something where you are directly optimizing the deployment or operation of real physical assets.