  We present a statistical approach to assess the dust environment for a yet
unknown comet (or when its parameters are known only with large uncertainty).
This is of particular importance for missions such as ESA's Comet Interceptor
mission to a dynamically new comet.
  We find that the lack of knowledge of any particular comet results in very
large uncertainties (~3 orders of magnitude) for the dust densities within the
coma. The most sensitive parameters affecting the dust densities are the dust
size distribution, the dust production rate and coma brightness, often
quantified by Af$\rho$. Further, the conversion of a coma's brightness
(Af$\rho$) to a dust production rate is poorly constrained. The dust production
rate can only be estimated down to an uncertainty of ~0.5 orders of magnitude
if the dust size distribution is known in addition to the Af$\rho$.
  To accurately predict the dust environment of a poorly known comet, a
statistical approach as we propose here needs to be taken to properly reflect
the uncertainties. This can be done by calculating an ensemble of comae
covering all possible combinations within parameter space as shown in this
work.
