What is the greenhouse effect?

US, WASHINGTON (ORDO NEWS) — They say that the Earth is located in an ideal “Goldilocks zone” far from the Sun (not too cold and not too hot area), which allows life to flourish on the surface of the planet. But mild Earth temperatures would not have been possible without the greenhouse effect, which traps solar energy on the Earth’s surface and keeps the planet warm.

The greenhouse effect is due to the atmosphere of the Earth. Visible sunlight, as well as invisible ultraviolet and infrared waves can penetrate the gas layer that covers our world. Approximately 70% of these energy rays are absorbed by the Earth’s oceans, earth and atmosphere, while the remaining 30% are immediately reflected back into space.

When the surface of the planet heats up, it releases part of this infrared energy that it has absorbed. But this energy does not come back from the gas atmosphere of the Earth. Instead of flying back into space, infrared energy is distributed across our planet and, therefore, raises the general temperature of the Earth. This is similar to how a glass greenhouse created by man works, trapping heat from the sun, it keeps plants warm in winter.

Without an atmosphere, our world would be as cold as a lifeless moon, with an average temperature of -153 degrees Celsius. Due to the greenhouse effect, the Earth maintains an average temperature of about 15 ° C.

Greenhouse gases and climate change

Greenhouse gases include several natural molecules – such as water vapor, carbon dioxide, methane, nitrous oxide and ozone – as well as several industrial ones such as chlorofluorocarbons. Over the past century, human activities such as burning fossil fuels, intensive agriculture, animal husbandry and land clearing have dramatically increased the concentration of greenhouse gases in the Earth’s atmosphere to such an extent that it changes the climate of our planet.

According to the US Environmental Protection Agency, since the mid-20th century, greenhouse gases produced by humans have become the most significant contributor to climate change. The level of carbon dioxide in the atmosphere has increased by more than 40% since the start of the industrial revolution, from about 280 ppm (ppm) to over 400 ppm today.

According to the Institute of Oceanography. Scripps in San Diego, the Earth’s atmosphere for the last time had similar concentrations of carbon dioxide in the Pliocene era, from 3 to 5 million years ago. This is at least 2.8 million years before modern people began to roam the planet. Fossils show that forests grew in the Canadian Arctic during the Pliocene, and savannas and forests spread throughout the Sahara desert.

While some people still doubt the reality of anthropogenic climate change, the evidence for this is incontrovertible. Since the 1850s, the average global surface air temperature has increased by about 0.8 ° C, and the ocean temperature has been at the highest level in the history of observations.

Increasing greenhouse gas emissions over the coming decades is expected to harm human health, increase drought, raise sea levels and reduce national security and economic well-being worldwide.

The greenhouse effect on other planets

Since the greenhouse effect is a natural process, it also affects other bodies in the solar system. In some cases, this gives a warning about how things might go wrong. A great example of this is Venus, which is about the same size as the Earth, and not much closer to the Sun.

Billions of years ago, when the sun was cooler and fainter, Venus could have a temperate climate that could allow it to have liquid oceans on its surface. Modeling shows that the average temperatures on the planet ranged from 20 ° C to 50 ° C for about 3 billion years, potentially even allowing Venus to sustain life.

But as the sun ages and becomes brighter, an excess of water vapor enters the atmosphere of Venus. This powerful greenhouse gas retained heat and raised the temperature of the planet’s surface, leading to a vicious circle in which an increase in temperature led to an increase in the amount of water vapor in the atmosphere, further heating the world – a process known as the rampant greenhouse effect.

When the oceans of Venus evaporated, the tectonics of its planetary plates stopped, as there was no water left to help “lubricate” the displacement of the geological plates. The atmosphere, which was becoming increasingly dense, could slow down the rotation period of Venus, which led to its strangely slow rotation, in which the day passes in two years. The dense cloud cover also led to hellish surface temperatures on modern Venus, an average of 370 ° C – hot enough to melt lead.

“I think Venus is an important warning to us: the atmosphere in a greenhouse is not just a theory,” said Ellen Stofan, director of the Smithsonian National Museum of Aviation and Cosmonautics and former NASA chief scientist, earlier.

On Mars, greenhouse gases such as water and carbon dioxide could be released during ancient collisions. Some scientists suggest that this could raise the total temperature of Mars, sufficient for the planet to have liquid water on its surface for significant periods of time. However, since Mars is smaller than Earth, its gravitational attraction is weaker. Therefore, these gases flew into space and eventually the Red Planet returned to the cold and dry world that it is today.

The distant moon of Saturn, Titanium, which has a dense atmosphere of nitrogen with about a thousand times higher methane concentration than on Earth, is also exposed to the greenhouse effect. Thanks to the Huygens probe of the European Space Agency, which landed on Titan in 2005, researchers better understand how methane absorbs short-wave infrared radiation and use this information to develop models of climate change on our planet.

It is also expected that the greenhouse effect will warm the worlds of other stellar systems. Many astronomers talk about the narrow habitable zone around the stars – the area where the planet will be at an ideal distance to maintain liquid water on its surface. For our star, this region extends in the interval from about 0.95 to 1.4 AU.

However, other scientists argue that such models need to be expanded. For example, a thick atmosphere of molecular hydrogen, which is a powerful greenhouse gas, can potentially give the planet an acceptable temperature, even if it is 15 times farther from the Sun than the Earth.

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