Final answer:
A positive Radiative Forcing (RF) implies an imbalance where more energy is retained in the Earth-Atmosphere system, leading to an increase in temperature, or global warming. This warming is accelerated by positive feedback mechanisms such as the melting of Arctic ice, which reduces reflectivity, and the increase of water vapor, a potent greenhouse gas.
Step-by-step explanation:
A positive Radiative Forcing (RF) indicates that more energy is being retained in the Earth-Atmosphere system than is being lost to space. This will lead to an increase in the Earth's temperature, a process better known as global warming. When an imbalance occurs where the Earth absorbs more energy than it radiates, the Earth's surface temperature will rise.
Examples of positive feedback mechanisms include:
- The melting of Arctic ice reduces surface reflectivity, leading to more solar energy absorption and further warming.
- Warmer temperatures increase water vapor in the atmosphere (a greenhouse gas), which in turn amplifies the greenhouse effect and warming.
- Higher temperatures lead to an increase in infrared radiation emitted by Earth, but if this is outweighed by increased greenhouse gases trapping more heat, then the overall effect is warming.
On the other hand, negative feedback effects act to balance and reduce the warming. An example of this is the increase in infrared radiation to space as the Earth’s temperature rises, which provides a cooling effect. However, positive feedbacks like the melting Arctic ice and increased water vapor typically overwhelm these negative feedbacks, leading to overall warming.