18 16 strangely, there is no summer! In June, the snow became heavier. What happened?

18 16 coincided with the Jiaqing period of the Qing dynasty, that is, the twenty-first year of Jiaqing. What is it called now? A year without summer? . That is, in this year, the seasonal changes that seem to be regular at ordinary times were suddenly broken. After the winter of 18 15, it was supposed to be a warm spring season for everything to recover, but this year's winter refused to leave for a long time, even in the long summer, the cold weather did not improve.

Summer is usually very hot. You may recall that no matter how cold the weather is, it must be at least ten degrees! But in this year, the earth hit a low point of the average annual temperature in human history. Not only did it affect spring ploughing, but frost also caused a large number of plants to freeze to death in winter. Among them, Yunnan is the worst-hit area, with a large number of victims. People suffer from hunger, and even in the end they can only sell their children in exchange for some rations.

However, as far as the whole Qing Dynasty is concerned, the whole country was relatively stable because of its vast territory and different degrees of disaster. According to records, there was snowfall in June and July in Anhui and Jiangxi. Many provinces, including Taiwan Province Province, have experienced rare frost. So in China, people also call it this year? Freeze to death 18 16? .

In fact, not only the Qing Dynasty, but also many countries and regions in the northern hemisphere experienced a rare low temperature in the same period. In the whole northern hemisphere, Europe suffered the most. At that time, Europe was ending its war against Napoleon. It can be said that everything is in ruins. People are suffering from war. Besides food shortage, people are eagerly looking forward to the arrival of spring. Unexpectedly, rivers continue to freeze, with heavy snow all year round, grasslands fade, animals die and starve. It is estimated that nearly 200,000 people have been frozen and starved to death in Europe alone. The situation in North America is also not optimistic. At that time, 88-year-old doctor Edward wrote in his diary:

The above is the situation in the northern hemisphere in 18 16. It was impossible for people at that time to know what happened. But modern science can find a reasonable explanation for this abnormal phenomenon. So the reason is that the earth's climate changes greatly? Into the ice age? Is there something wrong with the sun? Let's analyze the factors of the earth's temperature change:

Solar luminosity problem?

1. Has the inclination of the earth axis changed?

2. The problem of the earth's own atmosphere?

We know that both light and heat on the earth come from solar radiation, and the temperature of the atmosphere is mainly due to the sunlight shining on the ground, which heats the atmosphere through the secondary radiation (infrared radiation) on the ground, and the thickness and composition of the atmosphere will also affect the temperature of the atmosphere. The change of the inclination angle of the earth's axis relative to the ecliptic plane will also affect the light reception per unit area in the northern and southern hemispheres of the earth.

What if something goes wrong with the sun this year? According to our current knowledge of astrophysics, this will not happen, because our sun is a G-class star with a life span of about 65.438+0.2 billion years. At present, it only exists for 4.5 billion years, which is in the prime of life, and there will be no big fluctuation in luminosity and radiation in a short time.

The other is the change of the earth axis. As we know, the inclination of the earth's axis relative to the ecliptic plane is the main reason for the change of the earth's four seasons. If the summer in the northern hemisphere does not come this year because of the violent fluctuation of the earth's axis, the temperature in the southern hemisphere will also change and heat up. We can still see that the position of the sun in the northern hemisphere will be close to the horizon, not at the top of the sky, but this has not happened in historical records.

Moreover, we now know that the earth's axis is relatively stable. Although precession will occur and the world will enter the ice age in a certain period, the precession period of the earth's axis is 25800 years. In other words, the temperature change caused by the change of the earth's axis will lead to the long-term change of global temperature, not just in the northern hemisphere or just in one year.

So the last problem left is the atmospheric problem in the northern hemisphere. We know that the increase of greenhouse gases such as carbon dioxide, methane and water vapor will lead to climate warming, because these gases can prevent the earth from radiating heat into space, just like you sleep with a thick quilt at night. The increase of dust in the atmosphere will prevent sunlight from penetrating the atmosphere, so that a large number of sunlight will be blocked from outer space and cannot reach the ground. If the ground is not heated, the temperature of the whole atmosphere will decrease, resulting in short-term fluctuations in local climate.

So we found relevant evidence in the records of some years before 18 16, starting from 18 12, and starting from this year to? A year without summer? The world has entered a period of geological activity. In the past four years, large and small volcanic eruptions in the world have caused serious pollution of the global atmosphere. Volcanic ash has been in the stratosphere for a long time and cannot be dispersed. In other words, there have been some small changes in the climate in recent years, but they have not attracted people's attention.

The real fuse happened in 18 15, and the Tambora volcano in India erupted on a large scale. This is one of the biggest volcanic eruptions in human history. The height of the ejected lava is more than 45km, which directly sends as much as1.60km2 of volcanic ash into the stratosphere, including1.2000 tons to1.300 million tons of sulfur dioxide. These substances have spread all over many countries and regions in the northern hemisphere, seriously preventing sunlight from penetrating the atmosphere.

It is the pollution of the earth's atmosphere caused by volcanic eruption that causes the abnormal temperature in the northern hemisphere in the coming year. It should be spring, but it's snowing heavily and mixed with volcanic ash. The sky looks strange all day. However, today's global temperature is just the opposite, and we will even experience a long "winter-free year" in the future.