Via David R. Legates
A recent CNN article titled “The world’s rivers are drying up because of extreme weather. Watch Way 6 Seen from SpaceIt is argued that rivers such as the Colorado, Yangtze, Rhine, Po, Loire and Danube are drying up due to “lack of rain and relentless heat waves”. The article concludes that “the human-caused climate crisis is driving extreme weather globally”, which causes these rivers to shrink in both length and width and potentially become more severe. so it’s almost insurmountable.
While it is true that these rivers are indeed in low-flow conditions, it has long been argued that floods, droughts and runoff are driven by a number of factors beyond rainfall. Yes, the lack of rainfall over a long period will likely cause low flows in the rivers in the region. But not necessarily the existence of low flows indicates that lack of rainfall is the culprit. Humans need water not only to survive but also to carry out many water-intensive industries including paint and coatings manufacturing, paper mills, wineries, pesticides, and the production of other agrochemicals. , such as. Agriculture also has a high demand for water, and simple population growth can tax existing water supplies.
So it would be unrealistic to simply assume that the low flows in the six rivers that the CNN article focused on were due to a lack of rainfall and the “relentless heatwaves” that are thought to have swept the planet. In fact, the usual mantra of climate alerters is that rainfall will increase, not decrease. The rationale for this is that warmer conditions lead to more evaporation (remember that more moisture can be held in saturated air at warmer temperatures than at cooler temperatures), so , will lead to more rainfall, because “what goes up, must come down.” However, contrary to actual physics, we are told that the climate becomes more “variable” under climate change. climate change in what is known as “climate change.” This helps climate alarmists argue that both floods and droughts will increase, as well as more snowfall and less snowfall. signs of climate change.
To determine if CNN is right in assuming that rivers are drying up due to “the human-caused climate crisis,” let’s take a closer look at some of these rivers.
Let’s start near home. The Colorado River is cited as the first example, and although CNN attributes its dryness to “a historic drought in the western United States,” they do not attribute the drought to man-made. . However, they do mention that “about 40 million people in seven states and Mexico depend on the river’s water for drinking, agriculture and electricity”. But judging the current conditions from USGS National Water Dashboard says that, as shown below, many flow stations in western Colorado and Utah are near normal, while in New Mexico and Arizona they are much higher than normal.
Dark blue and black dots indicate runoff is at or near record highs and the current forecast is for more rainfall. Actually, 20order The century is wettest century of the past millennium. Lake Mead (highlighted by the CNN article) is drying up, not because the flow in the area is already close to zero, but rather University of Alabama climate scientist Roy Spencer showsbecause the population of the “desert” has grown so much that the area’s water resources cannot meet the water demand.
Next, the CNN article focuses on the Yangtze River in central China. The controversial Three Gorges Dam is located on the Yangtze River, and its operation greatly affects the water levels of both the upper and lower parts of the river. The Three Gorges Dam is the world’s largest hydroelectric dam, but it also enhances the Yangtze’s carrying capacity by controlling its flow and reducing the likelihood of flooding for downstream communities. It has adversely affected the landscape and ecology of the area, which is why it has become highly controversial, both domestically and internationally.
Earlier this year, an article in Science Alert (from a study published in the journal Geophysical Research Letters) suggests that the greatest climate change threat to East Asia is not from drought but from “atmospheric rivers” that would increase the rain due to more frequent and extreme events. So that is – lower flows or more flooding?
The remaining four rivers that CNN’s article focuses on are in Europe – the Rhine in Germany, the Po in Italy, the Loire in France, and the Danube in Romania. For the Rhine, the restoration of wetlands in the German mountain ranges has had an impact on summer runoff, particularly because of the “recession flows following higher peaks” (IEflow decreases after the flood peak increases), accordingly Wetlands International, causing the water to drain faster, thus creating a lower flow sooner. Po is also low due to drought, but its flow lower than it was seventy years ago – before intentional human-induced global warming. The effects of wetland drainage and widespread industrialization have also affected the river. Euronews reported an expert’s view that while Loire is “drier than usual this year,” some of Loire’s photographs “are at least a dramatization of the situation.” And the Danube in Romania is affected by the widespread development of urban land, the loss of floodplains and deforestation. All three will exacerbate flooding but reduce runoff in low-flow conditions because less water exists during transport into the river to maintain flow during low rainfall.
The most important factor, however, that overturns CNN’s argument that “the human-caused climate crisis is driving extreme weather globally” is causing the world’s rivers to dry up. the photo they chose to prove their point. For five of the six rivers they focus on (all but the Colorado River), their before-and-after aerial shots compare August 2022 with…August 2021 – just one year earlier. The drastic change in just one year leads to the indisputable conclusion that this is not a climate problem; rather, it is the normal variation of annual weather conditions and local effects in dam operation. Climate change is measured over periods of at least 30 years, not one year. On the Colorado River, diminishing flows are not the culprit behind low flows; The increasing water needs of the rapidly growing population in the desert Southwest of the United States is a much better explanation.
As usual, events often dismiss the alarmist view of climate change. This is no different for the CNN article.
David R. Legates, Ph.D., Director of Research and Education for Cornwall Alliance for Creative Managementis a former Professor of Climate and Geography at the University of Delaware and a co-author, with S. Fred Singer and Anthony R. Lupo, of 3rd edition of Hot Talk, Cold Science: Global Warming’s Unfinished Debate.
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