本文利用西元前220年至西元1839年，合計2060年中國的氣候、政治、軍事與水利資料，探討氣候環境變遷透過國防與治水等管道，對於中國政治制度的影響。結果發現中國近千年來相權衰微與君權擴張所造成的極權專制，主要肇因於：宋代以後中國氣候開始進入小冰河期。此時，較為寒冷、乾燥與極端的氣候，一則影響遊牧民族生存空間，迫使其必須武力南侵，導致北方外患頻繁；再則增加黃河含沙量，形成泥沙淤積阻礙河床，使黃河容易氾濫成災。兩大威脅因而迫使中國政治制度甚至是社會文化，必需朝向一個以國家主義為基礎的中央集權政體發展，以集中全國資源用於應付北方外患(例如：修築長城) 與整治黃河氾濫。以進化論的角度觀之，中國文化與制度針對發展環境變遷所為之調整，完全符合新制度學派所主張的制度進化法則。

This article uses a dataset covering the period from 220 B.C. to 1839 A.D. to investigate how natural environment influences political regimes through the channels of building Great Wall (national defense) and taming the Yellow River. The results obtained show that the presence of the autocratic monarch (or the weak prime minister) was caused by changes in weather patterns starting from the Song dynasty when the Chinese weather began to enter the Little Ice Age. The colder and extreme weather conditions worsened the living environment of northern nomadic people as well as increased the sediment concentration of the Yellow River. The former would, in turn, cause frequent Sino-nomadic conflicts, while the latter would increase the risk of the bank-breaching of the Yellow River. To address these two challenges, the Chinese political regime had to evolve toward a more autocratic and centralized state so as to ensure that limited resources were efficiently directed to prevent the nomadic invasions and the flood of the Yellow River. This kind of change in political regime in response to weather conditions is fully compatible with the law of evolution proposed by the neo-institutional school.