Final answer:
The statement is true; changes in solar output are too minor to account for the large increases in Earth's average surface temperature. The variation in solar energy output does have some influence on climate but is not the cause of recent global warming.
Step-by-step explanation:
The statement, "Although solar output varies, changes are too small to account for observed increases in average surface temperature on Earth," is true. Satellite data show that the energy output from the Sun varies by about 0.1% during a solar cycle, which is not significant enough to account for the drastic changes in global temperature observed in recent decades. While solar activity can influence local climate phenomena, like regional rainfall patterns or storm tracks, it does not explain long-term global warming.
The solar intensity has been relatively constant, aside from the 11-year solar cycles, since the mid-20th century. Therefore, it cannot be responsible for the recent warming trend. In contrast, greenhouse gases are known to raise air temperatures by absorbing infrared radiation, contributing significantly to climate change. This warming is primarily caused by human activities rather than variations in solar activity or other natural factors.