"Whiskey is for drinking; water is for fighting over."
-- Mark Twain (unverified)
Climate has always determined the availability of water resources. The human primate, proof of unintelligent design, has become a very potent force in depleting and destroying water resources. Together, it is recipe for disaster.
A study published in Nature last month showed that 80% of the human population lives in areas with severe threats to water security. A comprehensive review by Aiguo Dai at the National Center for Atmospheric Research (NCAR) paints a grim picture of the effects of climate change on water resources during this coming century. Drought will be the hallmark of the 21st century.
The detailed analysis concludes that warming temperatures associated with climate change will likely create increasingly dry conditions across much of the globe in the next 30 years, possibly reaching a scale in some regions by the end of the century that has rarely, if ever, been observed in modern times.
Dai first examined the relationship between the Palmer Drought Severity Index (PDSI) and surface temperature in the historical record. The PDSI is the standard meteorological measure of drought used in the United States, which serves as an excellent hydrologic accounting system. Precipitation and surface temperature are only climate variables with long historical records, providing a good starting point for analyses. These data indicate a strong but imperfect relationship between drought conditions and surface temperature. Severe persistent drought conditions were prominent in North America during the medieval warm period, particularly across the western half of the current United States. Temperature and precipitation data over the last half of the 20th century are also striking. Moderate to severe decreases in precipitation and runoff in river basins are evident across the western third of the United States in conjunction with rising surface temperatures.
From 1950 to 2008, most land areas have warmed up by 1–3◦C, with the largest warming over northern Asia and northern North America. During the same period, precipitation decreased over most of Africa, southern Europe, South and East Asia, eastern Australia, Central America, central Pacific coasts of North America, and some parts of South America. As a result, runoff over river basins in these regions has decreased.
Dai (2010), page 6
In modeling future trends, Dai suggests there will be clear winners and losers in the future availability of water resources. Apart from Alaska, the United States will likely be in the losers column.
A striking feature is that aridity increases since the late 20th century and becomes severe drought (sc PDSI pm <−3) by the 2060s over most of Africa, southern Europe and the Middle East, most of Americas (except Alaska and northern Canada, Uruguay, and northeastern Argentina), Australia, and Southeast Asia; while it becomes progressively wetter over most of central and northern Eurasia, Alaska and northern Canada, and India.</p>
Dai (2010), page 14
Dai has a nice set of graphic depictions of current and projected drought conditions. Here is the past decade.
Note the reds and purples over much of the United States, along with Central America, the western half of Latin America, the Mediterranean, and parts of southeast Asia.
With continued warming over this century, drought conditions are expected to go from bad to worse to disastrous.
The 2030s:
The 2060s:
The 2090s:
The growth of severe drought conditions across much of the United States in these models over the 21st century is unmistakable. These projections are based on "business-as-usual" assumptions about greenhouse gas emissions and rising global temperatures. So far, little has been done to speed the transition to clean energy to change these projections.
“We are facing the possibility of widespread drought in the coming decades, but this has yet to be fully recognized by both the public and the climate change research community,” Dai says. “If the projections in this study come even close to being realized, the consequences for society worldwide will be enormous.”
While regional climate projections are less certain than those for the globe as a whole, Dai’s study indicates that most of the western two-thirds of the United States will be significantly drier by the 2030s. Large parts of the nation may face an increasing risk of extreme drought during the century.
NCAR
While there are many uncertainties associated with modeling future hydrological trends, the historical record gives us little reason for optimism about what we can expect for water resources during the 21st century. Drought conditions in already densely populated areas or in areas vital to agricultural production will mean severe shortages of water, food, and whiskey. Anyone who suggests that global warming is likely to be good for us has the intelligence of a gnat and the ethics of a virus.
These models only address the supply-side of water resources likely to be affected by climate change. Our demand for water has also been increasing thanks to overpopulation, poor conservation of surface water sources, and our extravagant use of water in agriculture, power generation, and industry. And then there is the depletion and toxic degradation of our water resources to extract fossil fuels through unconventional recovery methods such as shale gas drilling, oil sands refining, and mountaintop removal coal mining.
Between climate change-induced drought, excessive water consumption, and water pollution, we are loading at least five bullets into the chambers of a six-cylinder gun. Instead of pointing the gun at our head, we are taking aim at our children, grandchildren, and great grandchildren.
Water will be on the ballot in the upcoming election. To get on the ballot as a Republican, you have to be a climate zombie that refuses to acknowledge scientific evidence of climate change, much less take any steps to reduce greenhouse gas emissions. What those zombies lack in integrity they more than make up for in campaign cash from the industries that would gladly trade water for oil, gas, and coal.