1. The term “greenhouse effect” has two common meanings. There is a natural greenhouse effect that keeps the Earth’s climate warm and habitable. There is also a man-made greenhouse effect, which is the enhancement of Earth’s natural greenhouse effect by the addition of greenhouse gases from the burning of fossil fuels (mainly petroleum, coal, and natural gas).
2. Earth’s natural greenhouse effect is critical to supporting life. But human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming.
与我们生存环境密切相关的另一种自然效应是“城市热岛效应”（urban heat island effect）。例如：
3. Temperatures are often a few degrees higher in cities than they are in their surrounding rural areas. This temperature discrepancy is the result of a bizarre phenomenon known as the urban heat island effect. As the name implies, the effect turns cities into islands of heat.
4. According to the latest statistics from the China Meteorological Administration, about one-fourth of the temperature rise caused by climate warming can be blamed on the urban heat island effect. This effect is adding to our woes.
5. A few occasional flaps of the wings of a butterfly in a South American tropical rain forest in the Amazon Basin may cause a tornado in Texas, the United States two weeks later. This is because the movement of the wings of the butterfly will bring about changes in the air system around it, and also cause weak air flow, which will lead to relevant changes in the air and other systems around it. This will cause a series of chain reactions, and eventually lead to significant changes in other systems.
6. In Norway, live sardines are several times more expensive than frozen ones, and are valued for better texture and flavor. It was said that only one ship could bring live sardine home, and the shipmaster kept his method a secret. After he died, people found that there was one catfish in his tank. The catfish keeps swimming, and the sardines try to avoid this predator. This increased level of activity keeps the sardines active instead of becoming sedentary.
Catfish effect is a term used in human resource management to describe how groups are motivated by the addition of a strong competitor. Actions for actively applying the catfish effect in an organization are called catfish management. This is a method used to motivate a team so that each member feels strong competition, thus keeping up the competitiveness of the whole team.
8. The halo effect of celebrities gives people a cloak of generalized trustworthiness which extends well-beyond their industry or expertise. The halo effect works both in positive and negative directions.
In sociology, the Matthew effect is the phenomenon where “the rich get richer and the poor get poorer”. In both its original and typical usage it is meant metaphorically to refer to issues of fame or status, but it may also be used literally to refer to cumulative advantage of economic capital.