field: A particular field is a particular subject of study or type of activity.
So the authors are using 'field' to mean area of study which has standard usage in English I think so probably didn't need to be explained further.
When the authors wrote:
"Nonetheless we think cataloguing these risks is important if we’re going to be serious about having an impact in important but ‘fragile’ fields like reducing extinction risk."
They are talking about 'reducing extinction risk' being a field of study. And the risks of doing damage to a that new field with early research.
'risk X' is a risk, and 'reducing risk X' is a field.
There is the (meta-)risk that you harm a field (the 'harming field Y' risk).
They're studying that (meta-)risk here, in an attempt to reduce it. The article is thus squarely in the 'reducing risk Z (of harming field Y (of reducing risk X)))' field.
Your misunderstanding of it poses certain risks, that this comment attempts to reduce, with a concomitant risk of failure, but that gets a bit complicated.
So the authors are using 'field' to mean area of study which has standard usage in English I think so probably didn't need to be explained further.
When the authors wrote: "Nonetheless we think cataloguing these risks is important if we’re going to be serious about having an impact in important but ‘fragile’ fields like reducing extinction risk."
They are talking about 'reducing extinction risk' being a field of study. And the risks of doing damage to a that new field with early research.