People tend to associate proximity with warmth, so it seems natural to assume the seasons are caused by changes in how far Earth is from the sun.
The real reason for seasonal temperature changes is that the Earth is tilted.
Right now, Earth is about 3.1 million miles farther from the sun than it is in early January when it reaches perihelion, its closest point.
So, while it’s true that Earth is receiving less energy from the sun right now, that detail barely registers compared to the power of the planet’s tilt.
A slight angle in Earth’s spin does far more to shape our seasonal patterns than a few million miles of extra distance ever could.
ATLANTA— While those of us in the Northern Hemisphere brace for more sunshine and scorching temperatures, our planet is spinning at its furthest point from the sun. Summer is almost here.
Friday at 3:55 p.m. A. Around 3 million miles further from the sun than it is at its closest point, ET, our planet arrived at what is known as the aphelion, the furthest point in its orbit.
This may seem counterintuitive, but it takes place every year in early July. The farther we are from the sun, the colder it should be.
It seems reasonable to believe that the seasons are brought on by variations in Earth’s distance from the sun because people often equate closeness with warmth. However, the distance of the planet is not a significant factor.
The tilt of the Earth is the actual cause of seasonal temperature variations.
Depending on the season, different regions of the world receive more or less sunlight due to the angle at which our planet rotates, which is roughly 23 to 5 degrees. Longer days and higher sun angles in July due to the Northern Hemisphere’s tilt toward the sun produce more direct sunlight, which adds to the heat of summer.
On the other hand, Earth’s orbital shape is merely a minor factor. There is not much of a difference between our closest and furthest points from the sun, despite the fact that it is somewhat oval in shape rather than round.
The Earth is currently 3 points 1 million miles away from the sun compared to when it reaches its closest point, perihelion, in early January. That is only a 3 to 3 percent difference when compared to its average distance of 93 million miles.
Sunlight spreads out as it moves, so even a relatively small change in distance reduces the amount of solar energy that reaches the planet by about 7%. This is minuscule in comparison to the tilt of the Earth.
How much of a difference is it? Let’s examine some instances.
Summertime solar energy entering Earth’s atmosphere is more than twice as much as wintertime solar energy in cities like Houston, New Orleans, and Phoenix, which are located close to 30 degrees north in latitude.
The seasonal change is even more pronounced at 40 degrees north. Almost 300 percent more solar energy is produced in cities like New York, Denver, and Columbus in the summer than in the winter, when it is only 145 watts per square meter.
Therefore, even though it is true that Earth is currently receiving less energy from the sun, the power of the planet’s tilt is so great that it hardly matters. Compared to a few million miles of additional distance, a small tilt in the Earth’s rotation greatly influences our seasonal patterns.
Summer feels like summer because of our angle toward the sun, not because of our proximity to it.
