While learning about orbits in physics, we were told that, "a force, such as gravity, pulls an object into a curved path as it attempts to fly off in a straight line." I'll use Newton's analogy for further elaboration: let's say a canon were to be fired off the top of a very tall mountain. Since projectiles have a parabolic trajectory, the cannonball would go up, stop briefly, then come back down. But, depending on the velocity at which it is fired, the cannonball would go up, and try to come back down; but since it has been fired so far away from the Earth, the ground would curve away from the ball. Therefore, the Earth's gravity would keep the cannonball in a perpetual state of "coming back down." In application to Earth, since the moon is constantly in a state of "coming back down," it is VERY slowly getting closer to the Earth...at least that's what we learned in class. (Some studies say otherwise.) I was wondering if this concept applies to the Earth's orbit around the sun. If so, could this possibly be an explanation for climate change?
Obviously there are flaws with this theory. The rate at which our environment is changing is accelerating much too quickly for our Earth's orbit to be the direct cause. But is it a contributing factor? According to studies published on physicsworld.com, "the Earth could be closer than previously thought to the inner edge of the Sun's habitable zone." This could mean that as the amount of CO2 increases in Earth's atmosphere, and as the Earth continues to orbit the sun year after year; the air's capacity to hold water vapor will increase as well. Water vapor also tends to act as a greenhouse gas in our atmosphere. As a result, the global average temperature will rise, and it has been theorized that the oceans would begin to evaporate. Our current average global temperature is 288 K; but according to Ravi Kopparapu at Penn State, if we continue burning this amount of fossil fuels in the future, our atmosphere could reach a catastrophic 340 K by the year 2100. Other studies don't foresee global temperature this high until the year 2300, but it is definitely rising.
So it turns out our orbit around the sun is a contributing factor in climate change.