TPO24 Lake Water 请教

wjrboxbbll01UID: 3433617

A given lake’s residence time is by no means a fixed quantity. It depends on the rate at which water enters the lake, and that depends on the rainfall and the evaporationrate. Climatic change (the result of global warming?) is dramatically affecting the residence times of some lakes in northwestern Ontario, Canada. In the period 1970 to 1986, rainfall in the area decreased from 1,000 millimeters to 650 millimeters per annum, while above-average temperatures speeded up the evapotranspiration rate (the rate at which water is lost to the atmosphere through evaporation and the processes of plant life). The result has been that the residence time of one of the lakes increased from 5 to 18 years during the study period. The slowing down of water renewal leads to a chain of further consequences; it causes dissolved chemicals to become increasingly concentrated, and this, in turn, has a marked effect on all living things in the lake.

wjrboxbbll01UID: 3433617

这是 最后一段 红色的句子 the result has been that.... 不应该是前面内容导致的结果的意思么， 这里逻辑对不上啊。
是我理解有问题么

richchangesUID: 3397430

今天做到这套题，也觉得这个题很诡异，更诡异的是这个问题现在竟然没人解决……