Risk analysis can be defined as "a multi-stage process that includes the identification/ characterization of a hazard or risk factor, assessment of the likelihood of occurrence, evaluation of impacts associated with that hazard, evaluation of mitigation measures (risk management), and communication of risks".
A risk assessment comprises hazard identification, hazard characterization, exposure assessment and risk characterization. A hazard is the potential of a risk source to cause an adverse effect. The sequential steps in risk assessment of climate change, environmental chemicals, loss of pollinators and invasive species are to identify characteristics which may cause adverse effects, evaluate their potential consequence, assess the likelihood of occurrence and estimate the risk posed by each identified characteristic of the impact factor (like climate change, environmental chemicals, loss of pollinators and biological invasions on biodiversity and ecosystems). Risk assessment may/will follow the 4 stages of the International Standard for Pest Management:

• HAZARD IDENTIFICATION: The aim is to identify pest(s) and pathways of concern and should be considered for risk analysis in relation to the identified risk area (e.g. habitat, region, state).
• RISK ASSESSMENT: This is the characterisation of risk based on an evaluation of the evidence to estimate the likelihood and consequences of an adverse event, and the associated uncertainty. The "adverse event" in this case is the introduction (entry and establishment) or spread of an invasive species. Risk assessment is split into three interrelated steps:
  • species categorization
  • assessment of the probability of introduction and spread
  • assessment of potential economic consequences (including environmental impacts).
• RISK MANAGEMENT: refers to the analytical process used to identify risk mitigation options and evaluate these for efficacy, feasibility and impacts in order to decide or recommend the most appropriate means to mitigate risks that are found to be unacceptable as a result of risk. The uncertainty noted in the assessments of economic consequences and probability of introduction are also considered and included in the selection of a pest management option.
• RISK COMMUNICATION: The final step is to communicate findings in terms that are clear to all stakeholders. The whole process from initiation to pest risk management should be sufficiently documented so that when a review or a dispute arises, the sources of information and rationale used in reaching the management decision can be clearly demonstrated. This final step is a critical one as it ensures that all parties understand the scientific and regulatory bases for the recommendations.

This sequential listing of steps does not imply chronology. Risk communication, in particular is a process that should occur from the beginning of the process. Whatever the method used, the results of a risk analysis must be understandable, useful, credible and tailored to the problem in hand.