If the Earth were a flat disc instead of a sphere, the patterns of solar radiation would be significantly altered. Currently, because the Earth is a sphere, the Sun’s rays strike different latitudes at different angles.

On a spherical Earth, solar radiation falling on the equatorial region is concentrated over a smaller area, whereas it is spread over a larger area in the polar region. This creates uneven heating, making equatorial regions relatively warm and polar regions much colder.

If the Earth were a flat disc, the Sun's rays would strike the surface more evenly. There would be no variation in the angle of the Sun's rays from the equator to the poles, meaning solar radiation would be distributed uniformly. Consequently, the sharp temperature differences between the equator and the poles would not exist.

Furthermore, the Earth's spherical shape and the tilt of its axis of rotation give rise to seasons and the changing length of daytime. A flat disc Earth would lack these specific geometric and tilt-driven variations, altering seasonal patterns completely.

Finally, the uneven heating of the Earth's surface across the globe is what drives global winds and ocean currents. Without the temperature gradient caused by a spherical shape, these critical natural processes would be drastically different or non-existent.