When reviewing impact assessments, look for bias. Often the authors think only of negative changes. This is not necessarily because of personal agendas (such as to assist animals, clean the air, or reduce the birth rate), but is primarily due to human nature. To guard against having a biased report, one should look for balance. Does the material articulate that things will be different and that there are pluses and minuses? There may well be more of one than another. Sometimes balance is reflected in the amount of text, or graphics made to illustrate impacts and often it is reflected in the number of negative versus positive impacts, the latter often left out completely at the first draft stage. If missing, they tend to be only partially treated thereafter as the authors slowly yield to reviewer comments. Examples of balance:
- Discussions of increased summer heat waves and deaths should also include the reductions of winter cold waves and hypothermia deaths. Far more people die of cold.
- Increased costs of home air conditioning need to be discussed in the same context as reduced heating costs.
- Increased mismatches between food availability in ecosystems need to also include reduced energy demands needed to maintain body temperature, such as for marine mammals and the fact that plants and cold-blooded animals usually grow faster when warmer rather than colder. Thus the food of most fish and mammals grows faster when warmer.
- Discussions of coral reef bleaching need to include the expansion of coral reef habitats.
- Discussions of agriculture and forestry problems such as regional droughts and changing types of plants must include the expansion of production areas, general increased precipitation, and CO2 fertilization.
- Discussions of poison ivy becoming more prolific because of wetter environments, warmer temperatures, and CO2 fertilization, should similarly treat agricultural crops and forests.
- Discussions of polar bear food constraints must include the impact on the seals and other items they kill.