Also see Table 4.2 in the text. This shows ratings of risks by the experts and the public, note the differences in prioritization. Damage to Planetary Systems, such as the atmosphere. The simple answer is no. However, unless attempts are made to rate and rank risks of different nature, action will be difficult.
Risk assessment involves uncertainty and assumptions.
At best, it provides estimates. At worst, it is useless, or leads to inappropriate action. This may involve extrapolation of limited test data. Several orders of magnitude of uncertainty may be involved, see Table 4.4. If the risk is determined to be nontrivial, we move onto the next stages.