mentions the word carbon neutral, it is estimated that everyone is familiar with it. But have you ever thought about why achieving carbon neutrality or what carbon neutrality has to do with me?
First, let's look at a curve between the change in global carbon dioxide concentration and the change in global average temperature. We can find that global temperature changes are positively correlated with carbon dioxide concentration, which means that as the carbon dioxide concentration rises, the global average temperature rises. Since 1880, the global average temperature has risen by more than 1°C.
Why does the global carbon dioxide concentration increase? With this question in mind, let's look at the second picture.
Figure 1-1
From Figure 1-2, we can find that global carbon dioxide emissions are increasing year by year. Increasing carbon dioxide emissions will inevitably lead to increasing concentrations of carbon dioxide.
Figure 1-2
If you explain the relationship between carbon dioxide concentration and temperature changes in this way, does it seem too pediatric? Just two simple pictures. Is there a more scientific explanation?
To this end, we introduce a schematic diagram of the global greenhouse effect. About 50% of the visible light radiated by the sun is absorbed by the earth's surface, and then radiant heat is generated. The presence of various gases (carbon dioxide, etc.) in the atmosphere prevents radiant heat from passing through the atmosphere. We know that carbon dioxide molecules are in a state of vibration all the time, and the faster it vibrates, the higher the temperature. When carbon dioxide molecules in the atmosphere are exposed to radiation, they will shield the radiation, absorb the energy of the radiation, and speed up the movement, which will increase the temperature.
Figure 1-3
As another example, when we park the car outside, when we open the door, we will feel the abnormal heat inside the car. This is the greenhouse effect. Sunlight enters the car through the glass, the gas inside the car traps heat, and the temperature inside the car is much higher than that outside the car.
Simply put, the principle that carbon dioxide causes global temperature rise is the greenhouse effect.
Having said so much, what does carbon neutrality have to do with ourselves?
First,Let's look at a picture. As of 2019, global greenhouse gas emissions are about 51 billion tons. If we do not take any measures, let it develop. Then, global greenhouse gas emissions will continue to develop along Path 1. It is foreseeable that the global average temperature will continue to rise. This will lead to a series of catastrophic problems:
Figure 1-4
○ Very hot weather will increase. Take East China as an example. The current hot time is from the end of July to mid-August, which lasted one month. As the temperature rises, the number of days of hot weather may change from one month to three months or even longer.
○ An abnormal climate disaster. As the average temperature rises, the humidity of the air will also increase, and more water vapor will rise to the clouds, which will inevitably be accompanied by changes in the climate and environment. Frequent extreme weather events such as floods in Henan will be the norm. In inland areas, such as Xinjiang, as the temperature rises, more water in the soil will evaporate, resulting in drier land, and soil desertification is bound to accelerate.
○ As the sea level rises, parts of the coastline will be submerged. Sea level rise is mainly due to the melting of polar glaciers and the expansion of seawater caused by rising temperatures.
○ Food crisis. According to reports, every 1°C increase in temperature reduces global wheat production by 5.7%. The current global wheat production exceeds 700 million tons, and a 5.7% decline in production means that the world will lose nearly 40 million tons of wheat. Similar problems will also occur in other major grains.
○ disease. Heatstroke is a disease that we are prone to in hot weather. The body's cooling is mainly due to the volatilization of sweat. If the humidity in the air is large enough to absorb sweat, the body is prone to heatstroke or even death from heatstroke. Suppose that as the temperature increases, the humidity in the air also increases. The temperature rises, we need to rely on the secreted sweat to remove heat, but the air humidity is high enough,Can't absorb sweat anymore. What should humans do at this time?
Isn’t that the more you talk about it, the more terrifying it becomes!
Fortunately, the world has a common understanding of greenhouse gases. In April 2016, the leaders of 170 countries gathered at the United Nations Headquarters in New York to sign the " Paris Agreement" on climate change issues, promising to control the global temperature rise within 2°C and strive to achieve 1.5°C temperature control Target. will reach the goal of carbon neutrality by 2050: the emission of greenhouse gases is equal to the absorption of greenhouse gases, and the goal of zero emission will be achieved.
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