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Excess greenhouse gases in our atmosphere are the main reason that Earth is getting warmer. Greenhouse gases, such as carbon dioxide (CO2) and methane (CH4), Nitrogen dioxide (NO2), Chlorofluoro carbons (CFCs), trap the Sun's heat in Earth's atmosphere. It's normal for there to be some greenhouse gases in our atmosphere. They help keep Earth warm enough to live on. But excessive high levels of greenhouse gases can cause too much warming. The burning of fossil fuels like coal and oil increase the amount of CO2 in our air. This happens because the burning process combines carbon with oxygen in the air to make CO2. It's important that we monitor CO2 levels, because too high CO2 in atmosphere can cause too much warming on Earth.

Sunlight shines onto the Earth’s surface, where it is absorbed and then radiates back into the atmosphere as heat. But the longer wavelengths of the infrared re-radiation from the Earth’s surface are unable to pass through the atmosphere. In the atmosphere, greenhouse gases trap some of this heat, and rest escapes into space. The more GHGs are in the atmosphere, the more heat gets trapped.

Plants can help to balance the greenhouse effect on Earth. All plants — from giant trees to tiny phytoplankton in the ocean — take in carbon dioxide and give off oxygen. The ocean also absorbs a lot of excess carbon dioxide in the air. Unfortunately, the increased carbon dioxide in the ocean changes the water, making it more acidic. This is called ocean acidification. Making power on-site with renewables and other climate-friendly energy resources can reduce greenhouse gas emission. Examples include rooftop solar panels, solar water heating, small-scale wind generation, fuel cells powered by natural gas or renewable hydrogen, and geothermal energy.

Greenhouse gases are gases in Earth’s atmosphere that trap heat. They let sunlight pass through the atmosphere, but they prevent the heat that the sunlight brings from leaving the atmosphere. The main greenhouse gases are:

• Water vapor
• Carbon dioxide
• Methane
• Ozone
• Nitrous oxide
• Chlorofluorocarbons

Overall, greenhouse gases are a good thing. Without them, our planet would be too cold, and life as we know it would not exist. Scientists are worried that anthropogenic activities are adding too much of these gases to the atmosphere.

Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide. It is one method of reducing the amount of carbon dioxide in the atmosphere with the goal of reducing global climate change.

Global warming potential (GWP) is the heat absorbed by any greenhouse gas in the atmosphere, as a multiple of the heat that would be absorbed by the same mass of carbon dioxide. GWP is 1 for CO₂. Species Lifetime (years) GWP (100 years) Carbon dioxide Variable 1 Methane 12±3 21 Nitrous oxide 120 310 HFC-23 264 11700 Sulfur hexafluoride 3200 23900 Source: IPCC Second Assessment Report

Species	Lifetime (years)	GWP (100 years)
Carbon dioxide	Variable	1
Methane	12±3	21
Nitrous oxide	120	310
HFC-23	264	11700
Sulfur hexafluoride	3200	23900

Source: IPCC Second Assessment Report

Carbon cycle is the process where carbon compounds are interchanged among the biosphere, geosphere, pedosphere, hydrosphere, and atmosphere of the earth. Carbon Cycle Steps: Following are the major steps involved in the process of the carbon cycle:

• Carbon present in the atmosphere is absorbed by plants for photosynthesis.
• These plants are then consumed by animals and carbon gets bioaccumulated into their bodies.
• These animals and plants eventually die, and upon decomposing, carbon is released back into the atmosphere.
• Some of the carbon that is not released back into the atmosphere eventually become fossil fuels.
• These fossil fuels are then used for man-made activities, which pump more carbon back into the atmosphere.

The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions, oxides, and molecules through redox reactions within and between the reservoirs of the planet Earth. The cycle incorporates biological, geological, and chemical aspects to circulate the oxygen molecule in the atmosphere. The entire cycle can be summarized as, the oxygen cycle begins with the process of photosynthesis in the presence of sunlight, releases oxygen back into the atmosphere, which humans and animals breathe in oxygen and breathe out carbon dioxide, and again linking back to the plants. This also proves that both the oxygen and carbon cycle occur independently and are interconnected to each other.

Over millions of years, Earth's climate has warmed up and cooled down many times. However, today the planet is warming much faster than it has over human history. Global air temperatures near Earth's surface have gone up about 1 degree Fahrenheit in the last century. One degree may not seem like much. However, this change can have significant impacts on the health of Earth's plants and animals.

The carbon budget is an estimate of the maximum amount of greenhouse gases that can be released into the atmosphere over time and still keep warming limited to a specified level. It is estimated that to remain below 2oC, the world could emit only about 2,900 billion tonne (gigatonne or Gt) of CO2 equivalent from all sources from the dawn of Industrial revolution till 2100. Till 2011, the world had already emitted 1,900 Gt of CO2 equivalent. This meant that only 1,000 Gt was left between 2011 and 2100.

Intended Nationally Determined Contributions (INDCs) is a term used under the United Nations Framework Convention on Climate Change (UNFCCC) for reductions in greenhouse gas emissions by countries. In its INDC, India has pledged to improve the emissions intensity of its GDP by 33 to 35 per cent by 2030 below 2005 levels. It has also pledged to increase the share of non-fossil fuels-based electricity to 40 per cent by 2030.