Lake Chad is an interesting lake. Very shallow, it shrinks dramatically with even a small drop of water level. in many cases, it has been used as a “poster child” of Global Warming induced drought.
Such as this (fairly balanced – it does talk about increased irrigation demand) article. I’ve bolded some bits:
Africa’s Lake Chad Shrinks By 20 Times Due To Irrigation Demands, Climate Change
ScienceDaily (Mar. 1, 2001) — In the 1960s, North central Africa’s Lake Chad was larger than the state of Vermont but is now smaller than Rhode Island. NASA-funded researchers using computer models and climate data now understand why Africa’s freshwater Lake Chad has been disappearing over the last 30 years.
Michael T. Coe and Jonathan A. Foley of the University of Wisconsin-Madison cite a drier climate and high agricultural demands for water as reasons why what was once one of Africa’s largest freshwater lakes is shrinking. “Lake Chad was about 25,000 square kilometers in surface area back in 1963,” Foley noted. Now the lake is about one-twentieth the size it was in the mid 1960s.
Oh No, Mr. Bill, Climate Change is drying out Lake Chad! (At least, that’s the part that got reported in the more hysterical reports). So what did the researchers do? Why, use computer model, of course.
Their paper titled “Human and Natural Impacts on the Water Resources of the Lake Chad Basin,” is being published today in the American Geophysical Union’s Journal of Geophysical Research. In their paper, Coe and Foley used an integrated biosphere model (IBIS) with long time-series climate data.
Which produced output that they then fed into another model:
They simulated the exchange of energy, water and carbon dioxide between vegetation, soil and the atmosphere, and tracked the changes in Lake Chad since 1953. They input the data from the biosphere model into a hydrological model and were able to estimate changes in river discharge, the amount of water in wetlands and in Lake Chad.
Using model and climate data, Coe and Foley calculate that a 30 percent decrease took place in the lake between 1966 and 1975. Irrigation only accounted for 5 percent of that decrease, with drier conditions accounting for the remainder. They noticed that irrigation demands increased four-fold between 1983 and 1994, accounting for 50 percent of the additional decrease in the size of the lake.
Though in that later decade irrigation accounts for the next 50%.
Lake Chad has always undergone seasonal and inter-annual fluctuations because it is less than 23 feet (7 m) deep. In recent decades, during wet periods the lake expands up to 10,000 square miles (25,900 square km). The warming climate and increasing desertification in the surrounding Sahel region have dropped water levels far below the average dry season level of 4,000 square miles (10,000 square km) to only 839 square miles (1,350 square km).
The Northern Africa Sahel region has experienced numerous devastating droughts over the last three decades. “Climate data has shown a great decrease in rainfall since the early 1960’s largely due to a decrease in the number of large rainfall events,” Coe said.
Lake Chad’s primary source of water comes from the monsoon rains that typically fall in June, July and August.
But even then, the irrigation demand must be blamed on climate change…
With a drier climate and less rainfall, agricultural areas become more desperate for water to irrigate their crops, and will continue draining what is left of Lake Chad. Foley said, “The problem is expected to worsen in the coming years as population and irrigation demands continue to increase.”
Scary Scary!!! Run for the hills…
It’s evil Climate Change drinking Lake Chad dry!!!!
But What About Now?
The Wiki says:
Lake Chad (in French Lac Tchad) is a historically large, shallow lake in Africa, whose size has varied over the centuries. According to the United Nations (UN), it shrank as much as by 95 percent from about 1963 to 1998 yet they also state that “The 2007 (satellite) image shows significant improvement over previous years”
So I’m wondering where to find “2007 satellite images” (or newer) and wondering why the AGW Warmistas have not been out there recanting their doom predictions about desertification… Hey, at this point we’re pushing 4 years of recovery!
From Radio Netherlands:
Published on 29 October 2010
Fishermen on the shores of Lake Chad look on downcast as children swim and play near their moored boats, which they cannot take out because the water level has risen and fish are inaccessible.
The government has banned fishing with fine-meshed nets to help preserve a range of species, but with the wide-meshed nets they use, Kinassorom’s fishing community can catch little when the lake is deep.
Guess that water is coming back.
Can we expect a retraction of those prior claims that “Climate Change” was causing it to dry out? Can we expect a statement that the water now rising in Lake Chad is because they were a bit wrong before and this is just part of a 60 year or longer natural weather cycle?
Can they at least mention that one side effect of the shrinking lake was that the fishermen had been able to catch more fish very easily? Or will we only hear that the evil “Climate Change” is now starving the poor fishermen as the Lake Chad level rises and it must all be our fault still?
Most of the fishermen of the island come from lakeside countries, Nigeria, Niger and Cameroon. Their situation is paradoxical: while for years Lake Chad has been getting smaller, abundant recent rain after a long drought has brought up the water level.
“The rain this year has come to upset our activities. It has made fishing difficult because the water has risen. I’m laid off while waiting for the water to go down. The nets we use don’t catch many fish,” said Kadada Haroune, a Hausa of about 30 from Nigeria, who lives on the island with his parents.
At the moment, he spends his days under the trees playing cards with his friends.
“Since the water level has gone up, fishing, which is the main activity of the village, has diminished,” said village chief Adam Seid, who has lived on the island for 30 years.
In 1960, the size of the lake in central Africa was 25,000 square kilometres (9,650 square miles), but today it has shrunk to just 8,000 square kilometres (3,000 square miles) or even only 2,500 square kilometres (965 square miles), according to different estimates.
It will be very interesting to watch Lake Chad over the next decade or two. If I am correct, it will continue to rise over the next 20 years on this colder side of the 60 year cycle and PDO flip.
Expect to hear more hysterical claims that the “Hydrological Cycle Is Accelerating!!” and it’s all in keeping with the expected outcome of Global Warming!!!! (And expect to never hear about AGW induced drought causing Lake Chad to shrink in the prior 1/2 cycle…)