When we talk about greenhouse gases, we often look to the planet Venus as a prime example and with good reason.
Before 1962, when the Mariner 2 space probe became the first probe to reach Venus, and the Venera 7 probe became the first probe to land on Venus in 1970, we had always thought that Venus was our sister planet.
Venus is the brightest star in the dawn and evening skies because it’s the closest to us. It’s also almost the same size as the Earth. We thought we’d find a tropical paradise, lush with life. But the truth turned out to be terrifying. The similarity in size seems to be the only thing this evil twin has in common with the Earth.
Venus’s surface is so hot; it can melt lead. Temperatures can reach over 900 degrees Fahrenheit, and the atmospheric pressure can crush a human body flat in seconds. The toxic atmosphere is a thick, suffocating blanket of carbon dioxide. Oh, and it rains sulphuric acid, and it snows lead.
There have been theories and ideas as to how Venus came to be the monstrous hellhole it is today. Some say its slow rotation may be the cause. It takes Venus 243 days to spin on its axis- that’s longer than it’s 225 day year. It’s also much closer to the sun than the Earth, and as a result, receives more sunlight and heat.
The most accepted cause is Venus’s atmosphere. It’s mostly carbon dioxide. Carbon dioxide is a known greenhouse gas, and that is what should worry us here on Earth. On Venus, the carbon dioxide is caused by volcanoes. The greenhouse gas is so thick in the atmosphere that it creates a thick blanket around the planet, trapping heat from the sun, causing the surface to get hotter and hotter.
Venus could be a grim look at our future. And it’s thought that the planet wasn’t always like this. Scientists theorize that the planet may have once been a lot like Earth. It probably had oceans, oxygen, and maybe even life. But for whatever reason, the carbon dioxide, however it got there, caused the oceans to evaporate and whatever life might have been present to die out.
And on Earth, we have the potential to become even worse than Venus because we have another potential heat source- water vapor. If our oceans were to melt away, the vapor in the atmosphere could also act as a greenhouse gas and Earth could very well not only reach Venus’s hellfire temperatures but exceed them. The Earth could quickly put Venus to shame.
Venus is a glimpse of our future, whether we change our ways or not. We all worry about how Humanity affects the planet, and we certainly do. We can undoubtedly cause the greenhouse effect we see on Venus, but if we work together, we can avert this scenario- for a time. Because we still have one other enemy that could make us the Venus, we don’t want to be- the sun.
As the sun ages, it is getting brighter, and in a few billion years, it’s energy and heat could cause the runaway greenhouse to affect we fear. Hopefully, by then, we will have found a way to leave- or maybe we will have managed to kill ourselves off by then. No one knows, but one thing is for sure, we certainly don’t want to be around to find out.
The moral of the story is that even the Earth isn’t immortal. We only have a finite time with our planet, and we should probably try to take care of it for as long as we can. No need to turn it into Venus before it’s time, right?