Chapter 36: How Can Frozen Soil Allow Grain to Grow?

"Almost impossible."

Facing the old man's keenly interested gaze, Lu Beigu said, "Times change, and the Tibet of now is utterly different from the Tibet of then. Although Gtsang-sde was nominally the King of Tibet in his early years, he was in reality a puppet in the hands of the leaders of the Hehuang region and powerful chieftains. Now, though he has become the true ruler of Qingtang Tibet through various means, he remains, at his core, merely the leader of a tribal alliance, capable of rallying the tribes for defense but lacking the drive for expansion."

"Therefore, when Qingtang Tibet fights the Xia Kingdom, if they hold a firm defense, they often force the enemy to retreat by relying on their greater endurance of the harsh snowfield environment. However, whenever they launch an offensive, they are inevitably routed because each tribe fights alone, distrustful of one another. The root cause lies in Gtsang-sde's inability to centralize power. Even if our court trades with them, the bulk of the profits go to the subordinate tribes. Thus, these tribes are difficult to mobilize to risk cutting off trade and execute an offensive strategy they are not skilled at."

"Moreover, our court has fortresses scattered across the northwest. Even Li Yuanhao failed to bring his troops to the gates of Chang'an; how much less possible is it for Qingtang Tibet?"

The old man nodded. This youth spoke with reason and was not intimidated by his sudden interrogation.

In that case, this 'Strategy Against Xia' must have been written by the youth himself; otherwise, he could not have answered these questions.

But the old man continued to press, pushing his advantage: "However, you also said that times change. Now, Qingtang Tibet cannot fully centralize power and is not skilled at offense, but how do you know they cannot do so in the future?"

Lu Beigu looked out of the hall.

The current situation was somewhat complicated. Should he answer or not?

And the fact that Li Pan was nowhere to be seen left Lu Beigu somewhat undecided.

However, Li Pan's actions also served to verify the identity of the old man before him: he was most likely not Zhang Fangping.

The reason for Lu Beigu's deduction was simple. Li Pan, being such a pragmatist, would certainly not miss the opportunity to pay his respects to Zhang Fangping and make his presence known. If this were truly Zhang Fangping, he would have entered, rather than letting Lu Beigu handle things alone.

And the old man's sheer tenacity, with question following question, indicated that Li Pan must have known at this time that the other party was not someone to be trifled with, and thus had deliberately avoided the encounter.

But Lu Beigu had nowhere to retreat. Furthermore, even putting that aside, whoever the old man before him was, the mere fact that he appeared here already indicated his extraordinary status.

Therefore, for Lu Beigu, who had been brought here, it made little difference who he was speaking with.

Because no matter who he faced or what question was asked, he had to strive to answer.

It was just that the old man's question was truly tricky, even bordering on being contrarian.

But was there any possibility to such a speculation?

There certainly was. Just as people in this era could never imagine that the Jurchens, currently toiling in the deep, old forests of northeastern Liao, a tribe so weak and insignificant, would decades later destroy both the Liao and Song, two vast empires spanning ten thousand li. On what basis can you assert that if formal trade fattens the currently weak Qingtang Tibet, it will not recreate the glory of the Songtsen Gampo era?

It is certainly impossible to infer the future based on current conditions. After all, if a great ruler were to emerge, first submitting to Great Song to accumulate capital through trade, then consolidating internal power to achieve centralization before expanding outward, would Great Song's move not be raising another grave threat to its own heart?

Logically, by the time the discussion reached this point, it was essentially a deadlock, since Lu Beigu could not prove events that had not yet happened in the future.

However, Lu Beigu shifted his argument and said:

"But the most important basis for my judgment is actually the climate."

The term 'climate' actually existed in ancient times and is not a modern vocabulary.

The 'Emperor Neijing · Suwen' wrote, 'Five days constitute a Hou, three Hou constitute a Qi.' By the Warring States to Western Han periods, 'climate' began to be used as a compound term to describe the cyclical changes of solar terms and phenology in a year. The 'Liji · Yueling Commentary' records, 'In the past, Duke of Zhou established the system of seasons, determined the twenty-four solar terms, and divided them into seventy-two Hou; thus, the origin of climate.'

And by the Former Tang, with the increase of records on climate in agricultural texts such as 'Qimin Yaoshu', the term 'climate' gradually evolved to include elements such as precipitation and temperature.

So the old man encountered no obstacle in understanding this, but regarding this theory, he still felt curious.

"Oh?"

He placed the policy paper in his hand on the desk, a flash of strange color passing through his eyes, and asked, "That sounds interesting. How so?"

"The 'Tang Shu · Tibet Biography' compiled by Liu Xu of the Later Jin, and the 'Tongdian · Tibet Biography' compiled by Du You of the Former Tang, besides describing the Tibetan official system, laws, products, and customs, also mentioned that during the time of Songtsen Gampo, the snowfields could grow grain extensively, supporting an army of hundreds of thousands. Later, I consulted Former Tang notes and learned that at that time it was precisely the 'Warm Period'; the snowline had shifted significantly higher than today, allowing the Tibetans to expand cultivation onto the snowfields."

"However, various notes from the Late Tang and Five Dynasties record that since the end of the Tang, the northern lands gradually grew colder with constant wind and snow, many poplars in the Western Regions withered, and the snowline on the snowfields shifted downward again."

"How can frozen soil allow grain to grow? Today, the arable land on the snowfields can support at most a million households. If they expand outward, once they launch a distant expedition and cannot replenish supplies locally, it is simply impossible to sustain it."

"This theory is indeed novel."

The old man was greatly surprised and, intrigued, continued to press: "Then how long does it take for the snowline on the snowfields to shift upward and then downward again? Have you studied this?"

"If we speak solely of the snowline on the snowfields, there is currently no precedent. As you said earlier, the Central Plains only learned that the snowfields could be inhabited and traded with during the Northern and Southern Dynasties through dealings with Tuyuhun. Before that, there were no records; it was likely uninhabitable."

At this moment, Lu Beigu said, "However, if we look at the historical records of the Central Plains, we can discern some clues."

The old man's eyes showed even more surprise, and he tapped his fingers lightly on the desk: "So, you are inferring the cold and warmth of the climate from the phenology recorded in historical books?"

"Exactly."

Lu Beigu nodded and said, "The 'Book of the Later Han' records, 'In the sixth year of Guanghe of Emperor Ling, in winter, there was great cold; in Beihai, Donglai, and Langya, the ice in the wells was over a chi thick.' And the 'Records of the Three Kingdoms' records, 'In the sixth year of Huangchu, in the tenth month of winter, the Emperor traveled to the old city of Guangling, inspected the troops by the river. There were over a hundred thousand soldiers, with banners stretching for hundreds of li. That year was extremely cold; the waterways froze, boats could not enter the river, so he withdrew.' Thus, it can be seen that in the late Han and Three Kingdoms periods, the area north and south of the Huai River had already become extremely cold."

"However, the 'Book of Song' and the 'Book of Southern Qi' record that the area north and south of the Huai River often had no snow and drought in winter. The difference in cold and warmth during this period can already be distinguished."

"Therefore, from the late Han to the Southern Dynasties of Song and Qi, the world's climate began to shift from cold to warm. Later, from the Eastern and Western Wei to the early Tang, the warmth gradually increased, the snowfields melted, and Tibet thus grew strong. By the late Tang and Five Dynasties, it turned cold again. This waxing and waning, this cycle, seems to follow a pattern."

"The course of heaven has its constancy; it does not exist for Yao, nor does it perish for Jie. The prosperity of Tibet was due to the Warm Period gaining fertile soil; its decline was also due to the arrival of the Cold Period making the frozen soil difficult to cultivate. Therefore, this student believes that although Qingtang Tibet currently holds Hehuang, its agricultural foundation is already lost. Even if a great ruler emerges, it will be difficult to restore the former glory of Songtsen Gampo."

Suddenly, a gust of wind rose outside the window, rippling the water of Moho Lake, and the lotus flowers swayed.

"Interesting! Extremely interesting!"

The old man looked at Lu Beigu and said approvingly, "Your theory of 'Cold Period' and 'Warm Period' coincides with the ancient theory of 'Five Movements and Six Qi', but the ancients mostly spoke of celestial phenomena corresponding to human affairs, whereas you discuss rise and fall through cold and warmth; this is indeed a fresh approach."

"If we follow this theory, are the northern barbarians also rising and falling due to changes in cold and warmth?"

(End of Chapter)