What It Would Take to Change the Earth's Atmosphere to Be Like Venus
Venus, the world of volcanoes and intense heat, stands in stark contrast to Earth with its average temperature of 464°C on its surface. This planet is closely tied to its activity on the surface, with the thick, sulphur-rich atmosphere generated by the volcanoes there. Despite the fascination with transforming Earth's atmosphere to replicate Venus' conditions, such a task is no simple feat and hypothetical.
Aside from the striking similarities in size, Venus is far from being our twin planet. It is nearly tidally locked to the sun, resulting in a day and a year that are almost identical. This tidal lock would disrupt our sense of time—much like a challenge faced by blind individuals who rely on these distinctions. The rotation of Venus could potentially be sped up, perhaps with the introduction of a moon into its orbit. However, the primary hurdle remains the extreme heat. Venus is an oven at 900°F or 475°C, which would make living conditions unbearable without significant cooling solutions.
A cooling strategy would require enormous umbrellas to start, much like artificial sunshades. But even this would only be a temporary solution. The atmosphere of Venus consists of sulphur and carbon dioxide. While bacteria on Earth can break these down, they thrive in water, something which doesn't exist on Venus. One potential solution might involve landing asteroids containing water, which could help start the planet’s rotation back up or even be used to introduce water vapor into the atmosphere. NASA's ongoing efforts to move near-Earth objects (NEOs) might be harnessed for such a mission, or even for adjusting Mars' mass and gravity.
Chemical Removal of a Good Portion of the Atmosphere
Despite the complexity, some propose that chemical reactions could remove a significant portion of Venus' atmosphere. While this is an hypothetical effort, the process is fraught with challenges. One approach would involve launching a large icy comet to smash into Venus, filling its atmosphere with water vapor and clouds. The water would cool the planet and dissolve a large amount of carbon dioxide (CO2), potentially taking two centuries to develop the necessary technology.
Once the atmosphere is cooled, life forms such as foraminifera could be introduced to extract CO2 and convert it into limestone. However, the current temperature on the surface of Venus is approximately ten times hotter than what these organisms can tolerate. This would necessitate either genetic modification to their heat tolerance or an artificial method to reduce the sunlight reaching the surface, gradually cooling the planet. As the surface geology of Venus is still largely unknown, these efforts could easily go awry.
History has shown that transforming Earth out of a carbon dioxide greenhouse state took hundreds of millions of years. The process was marked by oscillations between a carbon-dioxide-rich environment and an overly oxygenated one, only reaching a stable state relatively recently. The task of changing Venus into a more Earth-like planet is a monumental challenge that hypothetical scenarios cannot fully capture.
As we continue to explore methods to alter planetary environments, such as terraforming, the distance and specific conditions of Venus make such endeavors highly speculative. Nonetheless, the potential for transforming the Earth itself into a more Venus-like environment remains a subject of both fascination and concern within the scientific community.