What is primarily responsible for causing the seasons on Earth?

The axial tilt of the Earth is fundamentally responsible for the changing seasons. The Earth is tilted on its axis at an angle of about 23.5 degrees relative to its orbital plane around the Sun. This tilt means that as the Earth orbits the Sun throughout the year, different parts of the planet receive varying amounts of sunlight at different times.

During summer in the Northern Hemisphere, that part of the Earth is tilted towards the Sun, which results in longer days and more direct sunlight. In contrast, during winter, the Northern Hemisphere is tilted away from the Sun, leading to shorter days and less direct sunlight. This variation in sunlight distribution is what creates the cyclical pattern of seasons.

The other options, while related to climate and weather phenomena in various ways, do not directly influence the seasonal changes in the way that axial tilt does. For instance, distance from the Sun does have some effect on seasonal intensity, but it does not significantly change from one season to another throughout the year. Solar output variations can cause longer-term climate changes but are not responsible for the immediate seasonal transitions. Geothermal activity has effects on local climates and environments but is not a factor in the systematic changes of seasons over the course of a year. Therefore, Earth's axial tilt