From the author:
Sustainable development is the key to a favorable life for humanity. However, unfortunately, we are still far from sustainable development and live in debt to our future generations. The resources of our planet are not infinite, and already now we can observe how, with the growth of the human population, there is no increase in land fertility, air purification from pollution, droughts are increasing, destroying crops, and waste is flooding more and more territories and water areas. 
The earth is our common home, for which we are responsible. Therefore, in order to preserve it for our future generations, we must act comprehensively. I have been working in ecology for 7 years and during this time I have studied the issues of degradation of protected areas, sustainable agriculture and environmental pollution with microplastics. I am pleased that people have begun to pay more and more attention to these problems and take measures to solve them, so I see the year 2100 quite optimistically. In this essay, I would like to remind readers of the importance of sustainable development issues, offer my vision of the future, and inspire them to develop methods to achieve sustainable development.

To date, promising areas of development in agronomy, biology and ecology are so unusual that a few years ago people could only learn about it from books of the genre "fiction". However, we can hear about discoveries and research that previously seemed impossible in the news, at lectures and in ordinary friendly conversation. Slowly but surely, they penetrate into our lives and help science move on. Therefore, the research and technologies that exist now will directly affect humanity in the future.
The first direction I would like to point out is a mixture of biology and computer science, because nowadays the IT sphere is developing very rapidly, various programs, codes, algorithms and even artificial intelligence are being created. Thus, by combining these two sciences, humanity will probably be able to learn the "code" of various types of organisms. And thanks to this, we will have the opportunity to get information about the most favorable conditions for the residence and reproduction of various organisms. So, having learned the "code" of some agricultural crop, scientists will be able to recreate the best conditions for its growth and reproduction, and by introducing various data, algorithms and calculations, humanity will be able to find out the best ways of reclamation for this crop. Digitalization of agriculture exists today, but it collects data on fields [1] and creates automation of basic agricultural processes such as irrigation and fertilizer supply [2]. Alternatively, organisms can be "programmed" to increase yields (for example, "force" alfalfa to add more nitrogenous compounds) [3] and carry out the best breeding selections, without resorting to genetic modification. This direction will help solve the problem of lack of food resources (hunger) and loss of fertility in some territories, because at the moment, increasing soil fertility is a huge cost: to increase yields by 2 or more times, the costs of all necessary resources per unit of cultivated area are multiplied many times: fertilizers – 4 times, fuel – 24.5, costs for the operation of agricultural machinery – 11.6 times, for irrigation – 2 times [4].
The second direction is also related to the problem of food shortages, as well as overpopulation. This is the development of agriculture in space and on other planets, because it is quite possible that a person will begin to move to other planets, and he needs food to live. With a long stay away from our planet, the stored resources will run out or deteriorate, so it will be necessary to equip your new place of residence through the development of space agriculture. Conducting crop production in difficult natural and climatic conditions is one of the main tasks of researchers in our country, and it is performed quite successfully, for example, in Antarctica, our scientists have grown watermelons, cucumbers, tomatoes and other plants suitable for food [5]. As for the "cosmic" achievements of agronomy, scientists were able to grow watercress and other plants on the lunar soil [6]. That is why I believe that in the future humanity will be able to provide itself with all the necessary elements, calories, and nutrients in outer space.
The next direction is already connected with the environmental problem of Land pollution. In order to reduce emissions from production, transport, housing and communal services, it is necessary to create filters. One of the filter options is to grow cultures of microorganisms that eat these emissions (CO2, SO2, NO2 and other pollutants), while it is necessary to solve the problem of their disposal and rational use. Alternatively, these microorganisms will not just preserve these pollutants in themselves, but break them down into harmless ones. Already today, there are organisms that eat petroleum products, they are used in accidents and spills of hydrocarbons [7]. Thus, these filters will help solve the problem of environmental pollution, reduce greenhouse gas emissions from industry and the fuel and energy complex. The rate of climate change will decrease, part of the greenhouse effect will disappear, and the number of extreme weather events will decrease.
The fourth promising area is the study of living organisms and the use of acquired knowledge in bionics. With the help of it, some engineering tasks will be solved and this will help the sustainable development of cities. Today, urbanism is a developing field, and by combining it with bionics, we will get absolutely the newest cities of the future. They will become environmentally friendly, energy efficient and will be able to withstand natural and man-made disasters (earthquakes, explosions). Buildings will be created from carbon-neutral materials, the least use of resources and improvement of various characteristics of buildings. An example of an "eco-friendly" skyscraper is the Lakhta Center [8]. All this will have a positive impact on other natural systems outside cities. Already today, the problem of overpopulation of cities (Tokyo, Guangzhou, Seoul and others) is relevant, and in the future their number will increase along with the size of the planet. That is why the processes of urbanization can leave a negative mark on our planet, and the use of knowledge in bionics will allow this trace to be reduced, or even to restore the disturbed balance. 
Thus, the future of mankind largely depends on its attitude towards the future, on values and priorities, on the degree of development of science and technology. As I said at the beginning of the essay, a lot of things that used to be fiction are now becoming reality. Therefore, it is quite possible that promising areas for the development of agronomy, biology and ecology within the framework of sustainable development, which now seem impossible, will be implemented by 2100. I believe that humanity will follow the path of sustainable development and achieve it.