Short version: After spending 4 very successful years as a postdoc at a top university in Switzerland, I was offered a promotion. However, the new contract comes with a very high teaching load (75%) for at least 3 years. It is also not a permanent position. I am afraid that the new position will limit my future career chances because I'll not be doing much (if any) research during this time and teaching will also not improve my chances in industry. Therefore, I'm considering declining the position.
Long version: I'm working in a young research group at a top university in Europe (Switzerland). Our professor is still in his tenure-track phase. I am probably the most experienced postdoc in his group and have many responsibilities and significant research output and an outstanding international research network. I'm also personal friends with him.
I'm in the fourth year of my postdoc (which I feel is already pretty long). In my last appraisal interview, I mentioned that I would like to progress with my career toward a more senior scientist-like position. In fact, I do not really have a lot of time to do my own research anymore but am instead supervising a lot of other people's research.
Within the institute, another senior scientist who did a lot of teaching now got a professorship at a different university and I was offered his position. However, it comes with a ton of teaching, more than I would like to do, and in a field that is not really my main expertise. Thus, in the next years, I will be very busy preparing lectures (and learning about the field). The contract officially lists 75% teaching load. Thus, I will have only very little time (if any) for doing research besides the other operational responsibilities that I have. Additionally, it is not a fixed position but only a temporary contract for a couple of years.
Although the professor basically promised me a great future (he is confident that he can turn my position into a permanent one in a couple of years after his tenure-track ends) I'm not fully convinced. First of all, these are only verbal promises and he mentioned that such a position is not only based on my teaching skills but also based on my success in getting funding for proposals and my research output. On top, our university is trying to reduce costs, thus, I'm not even sure if there will be permanent senior-scientist positions in the near future. (Some professors do not have one). He is also still on his tenure track.
My fear is that I will accept the promotion, will do a lot of teaching in the next three years (which I do not really want to do to this extent), and then not get a permanent position. In this case, I assume that the three years of teaching will not be beneficial for my academic career due to the reduced research output. Furthermore, I also fear that moving to the industry will get even more challenging (I will then be in my mid-30s). Unfortunately, there is no industry related to my field (we are doing fundamental research in a very niche field of radio astronomy). Thus, for a change to the industry, I would, either way, have to change my focus.
My question is if it is reasonable to decline the position.
I was already playing with the thought of moving to industry and I was already looking for suitable positions (without luck yet but also without really applying for many jobs). There is no time yet to explore my possibilities in industry before accepting/declining the promotion since he needs a decision soon.
If I accept, it obviously means I would stop looking for positions in industry (since I cannot agree on doing a lot of teaching in October but then leave mid-semester or even before the semester starts leaving the institute with nobody to do the teaching) meaning that I am "stuck" in the teaching position for at least some years.
Some colleagues from other institutes I talked to also raised concerns if this position will really be advantageous for my future academic or non-academic career.
The only related question I could find on this side was based on the US system, thus, I would appreciate some more suggestions/comments.