The substances which act as energy sources are known as fuels. The buried organic matters which can be converted to crude oil, coal, natural gas or any heavy oils by applying pressure and heat on earth's crust over hundreds of years are known as fossil fuels. Humans access fossil fuels today by drilling and mining into the earth to extract them from rocks and geologic formations.

In general, pesticides and industrialized farming fuelled by pesticides constitute a major source of warming the planet. Just like agrichemical corporations have been defending pesticides, powerful fossil fuel companies do the same for coal, petroleum and natural gas. The warmer planet is wrecking both human communities and wildlife. Melting ice wipes out food for large animals, including birds. Sea birds like puffins, for example, are starving to death in the millions per year. Pesticides are absorbed by crops, fruits, and vegetables. Of course, the amount of sprayed toxins reaching food is miniscule. But the impact of the sprayed chemicals in the body is cumulative. Mixed chemicals potentiate each other as well. Nevertheless, spayed food rarely kills people outright.

There are three main types of fossil fuels: coal, natural gas and oil. These three substances are used within the electricity and transportation sectors as an energy source. They're also the leading cause of the world's climate change. Coal is a solid fossil fuel that forms throughout millions of years by land vegetation and decay. When layers become compacted and are heated up over the years, the deposits are formed into coal. Coal creates large areas of peat which were covered in sediments over millions of years. As the sediments grew, the peat became buried ever more deeply and became coal. The mixture of sediments and creature remains built up throughout millions of years. The sediments turned to rock while the creatures turned to oil. This form of fossil fuel was formed during the same time as coal and oil. The main element found in natural gas is methane. Similar to oil, it moves in an upwards motion and can be trapped in a few different ways. There are two methods for extracting fossil fuels from the Earth: drilling and mining. While mining is the extraction process for solid fossils like coal, drilling helps to remove liquid or gas-like fossil fuels that can be forced to the surface. Both of these processes result in severe health and environmental impacts.

When planet absorbed sunlight, it releases a portion of the energy back into the atmosphere in the form of heat (or infrared radiation). Greenhouse gases such as carbon dioxide (CO2), methane (CH4) or water vapor (H20) absorb this energy and prevent the heat from escaping back into space. When we burn fossil fuels, it releases a large amount of CO2 into the atmosphere. Once this CO2 becomes released, it acts like a blanket, trapping heat and energy along with it - making Earth warmer. This process is also known as the "greenhouse effect."

According to NASA, the rise in temperature has created an effect with potentially dire consequences, specifically: the rise in sea level, melting of glaciers and polar ice caps, extreme weather conditions, and shifting climate patterns or climate change. A study shows that the melting of ice in Antarctica has soared by 75% in just ten years, which thereby increases sea level. The melting of polar ice caps, glaciers and rise in sea level point to some of the negative effects of climate change.

The escalation in average earth's temperature caused most of the wildfires, drought, and avalanches, an increase in water temperature that can affect the life cycle of sea creature and can also cause unpredictable weather pattern that can lead to extreme storms. Whatever the matter, some self- funded companies have emerged, making renewable energy affordable and available to use. People and political parties can be proactive in solving the dependency on non-renewable energy sources. According to West Coast Solar Energy, there is a new installation of solar systems. China, Germany, Netherlands are the leading country, with the most solar power installations.

The theme for world environment day 2021 is 'ecosystem restoration'. It can take many forms such as growing trees, greening cities, furnishing gardens, changing diets or cleaning up rivers and coasts. Ecosystem restoration assist the recovery of ecosystems that have been degraded or destroyed and conserving the ecosystems that are still intact. Research clarifies that healthier ecosystems with richer biodiversity emerge better benefits including fertile soils, timber and fish production. All kinds of ecosystems including forests, farmlands, cities, wetlands and oceans can be restored. Restoration happens in many ways such as through actively planting or by removing pressures on nature so that recover on its own.

Ecosystems restoration initiatives can be promoted and developed by government and development agencies. Bangladesh has been well aware of this problem for over a decade and has developed the Bangladesh Climate Change Strategy and Action Plan (BCCSAP) which has been implemented for nearly a decade and is now being taken it to 2030. Environmental hazards will likely be very crucial factor in present context. We have to ensure, development of mechanism to value ecosystems.

Shishir Reza, The Writer is an Environmental Analyst and Associate Member, Bangladesh Economic Association.