​Moments that contributed to the appearance of life in the universe are almost gone ● How soil changed life on Earth ● 50% of the Earth’s land must remain green to ensure the continuity of life

The moments that contributed to the appearance of life in the universe seem to have passed

At the beginning of the universe, there were only three chemical elements: hydrogen, helium and lithium. They are, in fact, the first elements in Mendeleev’s table. And all the stars that appeared in this early period consisted of three elements. During the lifetime of these primordial stars, but especially as a result of novae and supernovae, which marked the end of stellar existence, more and more chemical elements were formed.

Being devoid of metallic chemical elements, the first stars allowed only the appearance of gaseous planets. However, over time, as such chemical elements (including oxygen, carbon, and silicon) became more common, solid planets began to appear.

Based on this idea, we can extrapolate and say that a star rich in metals, metalloids and other elements with metallic properties significantly increases the chances of planets capable of supporting life. Well, that’s not quite the case, according to several researchers at the Max Planck Institute in a study recently published in the journal Nature Communications.

The astronomers in question say that stars poor in elements with metallic properties emit more ultraviolet radiation, but in a form that allows for the formation of a stronger protective ozone layer. Conversely, stars rich in these elements tend to lead to a thinner ozone layer, implicitly reducing the likelihood of life.

It all depends on the ratio of UVB or UVC solar radiation. If UVC rays are blocked by the ozone layer, UVB rays reach the surface of the planet and affect life forms.

Thus, Max Planck experts say, the appearance of an increasing number of stars rich in chemical elements with metallic properties, paradoxically, reduces the chances of life developing on solid planets around them. As it turns out, Earth was extremely lucky to form in a solar system where the Sun had the perfect concentration of chemical elements to allow life to arise.

Going even further, the study’s authors argue that it will become increasingly difficult for life to evolve as solid planets are sterilized by radiation. Another conclusion: if we want to find alien life, we will have to look for it exactly where we least expect it. In particular, around metal-poor stars. Come on, it’s not exactly rocket science.

How soil changed life on Earth

If we do mention the emergence of life, then we cannot fail to mention an article recently published in The Conversation magazine, an article that talks about the role of soil in the development of life on our planet.

As trivial as it may seem, the soil we all know today is no more than 450 million years old. Compared to the age of the Earth, which is 4.6 billion years, this means very little. Mostly reddish-brown soil begins to form with the appearance of the first dry plants. Theoretically, they appeared about 470 million years ago, although there are studies that claim that they arose much earlier. There is no doubt that through the Devonian, about 370 million years ago, we can also talk about the first colonization of the earth by forests.

Also, in the mentioned period, the thickness of the soil was already one meter. We are talking about a layer that is saturated with nutrients that are formed as a result of the decomposition of plants, that is, life. This allowed the appearance of plants with growing roots, which, in turn, transported organic matter deeper and deeper. It is clear that everything culminated in the emergence of a completely new ecosystem in which primitive life forms (arachnids, worms, etc.) found an ideal environment to thrive.

In addition to transporting nutrients, soil played another key role without which modern life would be impossible… the water cycle. The soil not only captured the water needed by plants, but also changed the face of the planet due to the appearance of riverbeds, rivers and other watercourses.

Last but not least is the soil, which captures carbon dioxide from plants when they die. Look, for example, what happens when you burn coal! Finally, the idea is that the soil of the Earth plays a much more important role than you imagine in the existence, but above all, in the continuity of life. It can be bad without it. Very bad.

50% of Earth’s landmass must remain green for life to continue

In the same vein, starting with soil and the dangers to life associated with its destruction, we cite another study recently published in Conservation Biology. In it, a group of researchers from the University of Queensland, Australia, reports that the goals that UN member states set last year are not enough to make a difference in the future of the planet.

In particular, this is an agreement that stipulates that 30% of the Earth’s land surface and 30% of the seas and oceans should become a protected area. In this way, soil health, clean air, clean water, biodiversity, God help us, would be ensured.

However, Australian experts say that all calculations were wrong, and saving 30% of the Earth’s surface by 2030 will not help us survive. Rather, at least 50% will be required. After all, we need at least half a green planet to be able to hope for the future.

The good part, the study authors say, is that the goal is achievable. The reality on the ground suggests that the downside is that it won’t be too late to set new goals.

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