By Md. Zillur Rahaman

April 22 is celebrated as World Earth Day. The Earth Day is a day set aside to save the earth from destruction of various events and it is an annual event that is celebrated worldwide on April 22 each year to show support for the protection of the environment. The day was first observed in 1970 and is now held globally by the Earth Day Network. The day is observed every year in more than 193 countries across the world.

The UN-sponsored conference in Rio de Janeiro, Brazil, from June 3 to June 14, 1992, is known as the United Nations Conference on Environment and Development (UNCED) or the Earth Summit (Portuguese ECO 92). After the long-running Cold War, the main objective of the conference was for member states to work together for sustainable development and save the environment.

The topics covered at the conference were:

1) Regulatory screening for production, especially for toxic components, such as lead in gasoline, radioactive waste, etc.

2) Finding alternative sources of fossil fuels that will also help mitigate the effects of climate change.

3) Creating human reliance on public transport to reduce vehicle pollution, reduce air pollution and reduce congestion in urban areas, and

4) Coordinate water use and sources. One of the achievements of this conference was the Agreement on Climate Change, which was later transformed into the Kyoto Protocol of Japan and the Paris Agreement.

The conference also paves the way for 1) global biodiversity agreement, 2) framework for implementation of climate change agreement and 3) formulation of UN policy on desertification.

In fact, human beings are constantly disrupting the environment by violating the balance and unwanted changes of life-sustaining elements. Man-made disasters include water pollution, air pollution, noise pollution, deforestation, biodiversity loss, warfare, and the use of nuclear energy. For centuries, people have been cruelly oppressing the environment for their own personal gain and for the betterment of life. The rapid spread of human misery, especially since the advancement of science, has led to the destruction of countless animals, plants and natural resources. The inevitable effects of this have begun to be felt in every corner of the globe. The burning evidence of which is the increase in global warming and the threat to biodiversity.

The flora and fauna are inextricably linked and their combination is biodiversity. The ecosystem is the dynamic system of interaction between plants, animals, microorganisms and their inert environments on the surface and among themselves. The main sources of food for most animals, including humans, are trees and livestock. Various species of plants and animals are on the verge of extinction due to indiscriminate deforestation and hunting of animals.

Many species of native fish and aquatic animals, on the way to extinction, are on the verge of extinction due to water pollution, reservoir problems and free hunting. Crop production is increased through pollination during honey extraction from various insect flowers including bees. The microorganisms survive by eating the organic matter of dead tree and animal cells and decomposing with these soils keeps the environment free from pollution. This flow of food energy through different organisms is called food chain. The food chain maintains the dynamics of the ecosystem. But the ecosystem is under serious threat due to man-made disasters, which have challenged our environment and livestock.

Contrary biodiversity is essential for the overall conservation and functioning of the biosphere to prevent environmental pollution. Plants play a vital role in maintaining the supply of oxygen to the environment and in causing rainfall. Biodiversity is actually a storehouse of a huge number of genes. This gene pool of different organisms is an invaluable resource to humans. This gene pool contains a number of high quality genes, which have been collected through biotechnology and transferred to economically important plants and animals to create high yielding transgenic plants and animals of desired quality. This makes it possible to meet the growing food needs of the human race.

But one of the risks of climate change is thunderstorms, excess rainfall and floods in coastal areas, which have already become apparent. These issues came up in the 2014 evaluation of the committee formed by the governments of different countries In most parts of Europe, Asia and Australia, the pressure is rising. Similarly, Heavy rainfall has intensified in North America and Europe, and in a few days, similar examples are being created around the world. Due to various man-made obstacles, the next world is becoming increasingly dangerous.

On the other hand, more than half of the world's people still live below the poverty line. These people are deprived of basic rights and privileges including food, clothing, shelter, education, medical care. But the developed countries are spending trillions of dollars behind the development of lethal weapons, specially nuclear weapons, to destroy the world. Without it, the leaders of the developed world would have benefited and found peace today if they had spent their time, labor and money on preventing man-made disasters around the world. If even a quarter of the budget that is being spent on the manufacture of weapons of mass destruction were to be spent on improving the quality of life of the human race, the world today would be free from hunger and poverty. And that would be the true practice of human rights and democracy.

The biodiversity of any country is the resource of that country. Different species of creatures make nature diverse and beautiful. Samples of these resources are stored in zoos, museums, botanical gardens to introduce them to the general public. As a result, aesthetic beauty and educational value increase. One study found that freshwater mammals, birds, amphibians, reptiles and fish have declined at an average rate of 4 percent per year since 1970. Humans are increasing the risk of climate change and biodiversity. As a result, the risk of genetic (contagious disease from other animals) diseases like COVID-19 is increasing. At the same time, the fear and threat of world catastrophe is increasing.

The reasons for environmental pollution and climate catastrophe are- 1) Contamination of water resources by unsuitable sewerage system. 2) The amount of waste including dirty waste in the water continues to increase. 3) The lion's share of the world's water has been filled. 4) Excessive use of other materials including plastics or metals, which are not easily decomposed and destroy the water and land environment. 5) Extinction of plant dependent animals and insects due to deforestation, change in rainfall pattern and deforestation.

Landslides and erosion increase due to deforestation. 7) Huge amounts of burnt fossil fuels from thousands of flying aircraft, scattering across the air. The result is carbon dioxide emissions and depletion of the Earth's protective ozone layer. Continuous liquefaction of millions of years of ice seas, ice islands, and mountain ice caps as the sun's radiation causes temperatures to rise. 6) Nitrogen oxides emitted from factories, power plants, various means of transportation, fall of harmful acid rain caused by sulfur oxide. 6) Contamination of marine and marine life through nuclear tests in the ocean floor or on land to establish world domination, political and economic influence. Contaminating the ground level and polluting the atmosphere to aggravate the catastrophe. 9) The use of newly discovered chemicals with the intention of increasing agricultural production several times due to population explosion and consequently destruction of oceans, rivers, agricultural lands and other lands, its adverse effects on climate and extinction of biodiversity.

However, natural reservoirs including rivers, canals, beels, ponds, ditches and haors scattered in different parts of the country play a huge role in maintaining the balance of the environment and protection of biodiversity. In addition, wetlands are important for keeping the environment cool, preventing floods during the monsoon season, reducing waterlogging in the city, meeting water demand and treating waste.

But people are filling the wetlands as they wish. But wetlands are very important for maintaining the balance of the environment, the survival of plants and animals. Moreover, floods, cyclones, droughts, tidal surges, tornadoes, earthquakes, river erosion, waterlogging and rising water levels and salinity are identified as major natural hazards in the world. In order to save the world, it is necessary to remove such natural and man-made obstacles and build a safe world, and this requires the awareness and joint efforts of all.

The writer is a Banker and Columnist