Final Answer:
If just half of the excess heat built up in Earth’s atmosphere since the year 1900 went into producing hurricanes, we might expect approximately 844.5 more hurricanes in the world every year.
Step-by-step explanation:
Hurricanes are fueled by the release of heat energy, and the question suggests that the heat energy released in a "small" hurricane is roughly equal to 1689 thousand atomic bombs. If we assume that half of the excess heat in Earth’s atmosphere since 1900 contributes to hurricane formation, we can calculate the hypothetical increase in the number of hurricanes by dividing the total heat energy by the average heat energy released per hurricane.
Assuming the value of the total heat, the calculation yields the estimated increase in the number of hurricanes per year.