We know that the sun that brings warmth to the earth, most of the ultraviolet rays in the sunlight are absorbed by the ozone layer in the upper atmosphere, and the rest of the light enters the atmosphere. The main components of the earth’s atmosphere are nitrogen and oxygen, which cannot absorb infrared rays, but others Trace gases such as methane, nitric oxide, water vapor, carbon dioxide, etc. will absorb infrared rays. Visible light reaches the surface of the earth through the atmosphere. While receiving sunlight, the earth will also radiate energy in the form of infrared light. Due to the existence of trace gases , The infrared energy from the surface of the earth will be accumulated in these gases, half of which will be emitted to the universe in the form of infrared rays, and the other half will be radiated back to the ground in the form of infrared rays, which locks up the heat energy from the sun and prevents it from being lost, causing the atmospheric temperature to rise High, this phenomenon is called the greenhouse effect.

Methane, nitric oxide, water vapor, carbon dioxide and other gases are all called greenhouse gases. If the sun alone, the surface temperature can only reach about -18 degrees, the whole world will be shrouded in freezing point, the current average surface temperature of the earth It is about 15 degrees Celsius. It is the thermal insulation effect of these greenhouse gases that makes up for the nearly 33 degrees temperature difference, allowing us to have a livable earth.

Among the greenhouse gases, carbon dioxide is a gas that emits a great amount in human life. If there is too much carbon dioxide in the atmosphere, it will be more difficult to lose heat, and the average temperature of the earth will rise accordingly, intensifying the greenhouse effect.

In the late 1990s, carbon dioxide emissions became an international issue that caused widespread concern.

Where does carbon dioxide come from?

Carbon dioxide accounts for about 0.03% in the atmosphere and 0.014% in the ocean. Carbon dioxide on the ground mainly comes from the burning of fossil fuels and other carbon-containing compounds, the decomposition of calcium carbonate ore, the respiration of animals, and the fermentation process. In recent decades, With the rapid development of industries all over the world, the amount of carbon dioxide emissions has increased, leading to the continuous accumulation of carbon dioxide. According to the calculations of the researchers, if the current emission rate is used, the content of carbon dioxide in the atmosphere may be as high as 1000 ppm.

Where will the emitted carbon dioxide go?

Green vegetation on the ground can absorb carbon dioxide in the atmosphere and fix it in vegetation and soil through photosynthesis. A broad-leaved tree can absorb 33 kilograms of carbon dioxide a day, and green plants around the world absorb tens of billions of tons from the air every year. We call it carbon sinks, including forest carbon sinks, grassland carbon sinks and arable land carbon sinks. The largest carbon sink in nature is the ocean. More than 50% of the carbon dioxide on the earth comes from the ocean and the organisms such as bacteria and plankton. Captured by organisms, seagrass, etc., the ocean recovers a large amount of carbon dioxide emitted by human industrial activities from the earth's atmosphere. The amount of biological carbon sequestered per unit of sea area is 10 times that of forests and 290 times that of grasslands.