What is the future of the Earth?

What is the future of the Earth?

Planetary scientists from the Geological Survey in Flagstaff, Arizona, USA have built a "Future Earth Climate and Geology" model. Through this model, people can perceive the earth hundreds of millions of years from now. Their views incorporate the latest evidence from geology, oceanography, atmospheric science, astronomy and other disciplines. Scientists believe that there are two important variables that govern the earth and life forms. One of them is carbon dioxide in the greenhouse effect, which can affect global temperatures; the other factor is the solar energy received by the earth.

The carbon dioxide in the atmosphere has dropped sharply

Today, we are worried about emitting too much greenhouse gases into the atmosphere - carbon dioxide will prevent the sun's heat from dissipating, thereby causing global climate change. warm. But the irony is that the cause of the catastrophe that will cause the earth's temperature to rise, the oceans to disappear, and life to be extinct hundreds of millions of years later is the lack of carbon dioxide in the atmosphere.

We humans should be grateful for the huge contribution carbon dioxide has made in keeping the earth's climate constant, because carbon dioxide acts like a natural temperature regulator. If for some reason the Earth begins to cool and ice ages begin to approach, the chemical reactions that absorb carbon dioxide from the atmosphere into the Earth's surface and oceans will slow down. At the same time, volcanic activity that erupts from time to time will still release carbon dioxide into the atmosphere. Therefore, the content of carbon dioxide in the atmosphere will accumulate more and more, which will increase the temperature again. On the contrary, if the earth warms, the reaction that sucks carbon dioxide out of the air will accelerate, and the temperature of the atmosphere will slowly drop again. This mechanism has worked effectively for 4 billion years, keeping Earth's temperatures less extreme.

In the long term, however, the Sun will become brighter, increasing by 1% approximately every 100 million years. This may not sound like a big deal, but as temperatures rise, chemical reactions that rely on heat will reduce the amount of carbon dioxide in the atmosphere, destroying the role of carbon dioxide as a temperature regulator. If this continues, in 500 million years, the content of carbon dioxide in the atmosphere will drop to a little more than 40% of the current level. Most plants will struggle to get enough carbon dioxide for photosynthesis, which will cause about 95% of plant species to struggle. Pines, firs and tropical forests will give way to grasses, shrubs and cacti, plants that can grow at relatively low levels of carbon dioxide. The amount of carbon dioxide in the atmosphere will continue to decline, and eventually, in about 900 million years, even these vegetation will be unable to survive. Eventually, the lush earth will turn into an earthy color.

The global environment will continue to deteriorate. About 1.2 billion years from now, the sun will be about 15 percent brighter than it is now. The temperature of the earth's surface will rise to 60 to 70 degrees Celsius, and the chemical reactions that absorb carbon dioxide in the atmosphere will become more active, almost causing the carbon dioxide in the atmosphere to disappear. The problem is compounded by a sharp increase in ocean temperatures, which in turn increases atmospheric humidity. Water vapor is also a greenhouse gas, but it does not act as a thermostat like carbon dioxide does. More moisture in the atmosphere means a rise in Earth's temperature, which in turn causes more water to evaporate from the surface. This vicious cycle will cause a runaway greenhouse effect: the oceans will eventually disappear, leaving only large dry salt flats; continental drift will slowly stop; complex animals will surely become extinct.

Day and night no longer alternate

The American Astronomical Association held a meeting in Monterey, California, in September 2003. At this meeting, scientists simulated and depicted What the earth's suffering will look like in the distant future: 7 billion years from now, the sun will expand into a huge red planet, scorching the earth; no one can accurately predict how the earth and moon will revolve around the sun at that time, but there is a way The possibility is that the Earth will be locked - it will be perpetual day on one side of the planet and perpetual night on the other side. In the future, on the side of the Earth where it is always daytime, the Sun will appear 250 times larger than it is today, occupying most of the sky, and the sunlight will shine very far away on the Earth, in fact only an area as big as North America. Always in darkness, the dark zone will be surrounded by an area that will always be in a state of twilight.

Scientists use astronomical predictions of the Sun's gradual brightening to calculate Earth's surface temperature. Through research, they found that in 7.5-7 billion years, the temperature of the magma sea under the sun will almost reach 2200°C, and the magma will begin to evaporate. However, the temperature of the Earth's surface on the night side is difficult to predict. If there is still a thick layer of atmosphere floating, it will bring enough heat to the night side, so that even the night side will become very warm; if there is no such layer of atmosphere, then the night side will be very warm. It gets very cold on the night side. This situation is very similar to Mercury, which has only a thin atmosphere. The temperature on Mercury can reach 350°C at noon, hot enough to melt lead. However, at night, the temperature drops sharply, down to minus 170°C. Scientists speculate that the temperature on the night side of the earth may be even lower, about minus 240 degrees Celsius, so this cold and hot earth will form some strange weather patterns.

On the hot side, metals like silicon, magnesium, iron and their oxides will evaporate from the magma sea. In the warm twilight zone they will condense again. You'll see iron rain and possibly silica snow. Meanwhile, potassium and sodium snow will also fall from the cooler, gray skies. On the dark side, it's cold enough to freeze carbon dioxide, sulfur dioxide and argon into a giant ice cap. The ice cap would have a layer of solid nitrogen ice, and underneath that would be water ice (if there was still water on Earth at that time). There is also a very small possibility that there is still a calm ocean of liquid water in the twilight region of the earth.

Having said so much, do we need to know these scary-sounding things? The answer is yes, because we should know that this moist oasis on which we live is the fierce and changeable environment of this blue planet. A rare and precious moment of peace in life—the blink of an eye from its roaring birth from the blazing heat to its long decay into ash and dissipation into space. It is best for us to cherish the beautiful world we live in now, and fully enjoy and protect this diverse and rich splendid world.

(Ma Wenhua is excerpted from "Encyclopedia Knowledge" Issue 1, 2005, by Chen Wanxin)

What kind of future will mankind have?

Today, the human environment is changing Experiencing the most rapid changes in history, where will this change lead? What are its prospects?

In order to answer these questions that people around the world are generally concerned about, various theories have emerged since the 1970s. The famous one is the "zero growth" theory based on the American book "The Limits to Growth" by John Maddows. On the basis of people's ecological needs, the British Gold Smith believes that the reformed industrial social ecological system cannot support the "balanced and stable social theory" of sustained economic growth; the British Shoemaker emphasizes the importance of the relationship between man and nature. The famous "miniaturization economic theory" of the United States; the "humanitarian social theory" of the American Karen Bass; the American Barclay and Sackler's "integrated structural theory of adjusting the physical, biological, economic and social aspects of human activities"; the American Cyprus Nika and Taussig's "compensation theory" based on the "world of scarcity": "Environmental economics of the transitional 'scarcity era'" by Cotnell in the United Kingdom; Fry in the United States to maintain a high standard of living indefinitely "The economics of an ideal ecological society" that has a comfortable environment and "ecological ethics"; the American Kahn uses historical methods to infer that the development of science and technology and human history and culture will inevitably lead to the "great transition" theory of economic growth; the British Mi Xiang attempts to coordinate The utopian "zoning theory" of modernism and environmentalism, which are in opposition to each other; and the regressionism and retroism of returning to nature that go further than Mixiang's dualism... These theories can basically be divided into three views: Pessimism school, optimist and realist.

The famous representative of the pessimists is the "Club of Rome", which was founded in 1968 and consists of more than 100 scientists, economists, educators and entrepreneurs from around the world. Their purpose is to explore the world What is the future of economic development and where is human society going? They strive to use scientific methods to describe the appearance of the future world and propose measures that should be taken to ensure the development that humans want. They have published some works with international influence, the most sensational ones. It's called "The Limits to Growth." According to their predictions, if the world continues to develop at the current growth rate in terms of population, industrialization, pollution, food production, and resource use, resources will begin to decline by the end of the 20th century, and by 2050, resources will suddenly drop to a very low level. At a low level; by 2040, environmental pollution will rapidly reach its peak, and will then moderate with the depletion of resources and the decline of industry and agriculture; the world's population will not grow to its maximum until about 2050, when The population will be tens of billions. They assert that the only feasible way to avoid eventual collapse of the world system is to pursue a zero-growth policy to maintain the stability of the world system.

There are many representatives of the optimists, such as H. Kahn, A. Toffler, B. Murray, D. Bell, etc. They all have monographs to systematically explain their views on the future. They believe that in terms of energy, mankind has begun to apply atomic energy in practical applications. Although solar energy, ocean energy, bioenergy and biomass energy are still in the experimental stage, there is no doubt about the future of success. The energy crisis can be completely overcome; in In terms of ecological environment, with the development of society and the progress of science, human beings can overcome all obstacles that may arise now and in the future, and can create a beautiful artificial ecological environment to maintain ecological balance; as for environmental pollution, as long as less than 2% of the energy is spent If the world's GDP is used for anti-pollution measures, the pollution caused by development can be completely solved, and the environment can be kept clean and good; in addition, the widespread application of genetic engineering, especially asexual reproduction, will provide humans with abundant food and Non-staple food; the fluctuation and quality of the population will also be placed under the control of human will... Therefore, they are highly optimistic and believe that mankind is entering the most creative and expansionary era in history.

There are also some realists who believe that the quality of the world tomorrow is not destined, but depends on the wisdom of the decisions made by humans in the next few decades