American Southwest threatened by heavy-rain monsoons

Posted on July 25, 2017 by GarryRogers

GR: The article below illustrates the value of scientific analysis. The Southwest Monsoon has always caused flooding. However, memory alone is an unreliable indicator of changes in storm strength; numerical comparison of time periods is better. The analysis mentioned in this article confirms the assertion that climate-change is bringing stronger storms to the Southwest.

Flooding is the primary danger from intense monsoon storms, but around my house you sometimes have to dodge falling branches too. Combining wind and rain-soaked leaves often breaks the brittle branches of the weeping willows surrounding my place. The one below fell on Sunday. It only weighs a few hundred pounds, but over recent years, branches weighing several tons have fallen. The ominous sounds of cracking and crashing lend wings to one’s feet.

Fallen weeping willow branch.

From LabRoots:

“A new study published recently in the Journal of Applied Meteorology and Climatology suggests that the North American Monsoon (NAM) is becoming more intense in the United States Southwest, particularly in Arizona. Their results show that while storms are not as frequent as they have been in the last 60 years, the rain episodes are heavier and include high winds, dust storms, and flooding, which often threaten residents and property. This pattern, the study concludes, is consistent with flux caused by climate change.

Monsoons often come on suddenly. Photo: The Arizona Experience

“Because of specific Department of Defense installations in the Southwest, and because the existing models of the NAM do not represent patterns in the climate accurately, the team analyzed Arizona rainfall data from 1950-1970 and compared it with data from 1991-2010. Defining severe weather events as days when the highest atmospheric instability and moisture occur within a long-term regional climate simulation, the scientists found that while the mean precipitation for the region stayed the same during the different time epochs, the later time period had more heavy-rain storms.” –Kathryn DeMuth Sullivan (More: American Southwest threatened by heavy-rain monsoons).

Climate Change Is Shrinking the Colorado River

Posted on June 18, 2017 by GarryRogers

Predicted Growth of Drought in the U. S. Southwest

GR: Here’s a helpful article that explains the drought disaster that is spreading across the southwestern U. S. There’s nothing new here, but the discussion clarifies some issues and will help you prepare for the inevitable changes. The article has an optimistic message, but the science is clear, life will become steadily more difficult in the Southwest, people will move away, and most will be gone from Arizona and large areas of surrounding states by 2100. It is inescapably obvious that we need to redirect the energy devoted to development in the Southwest and the corresponding effort to conserve water to forcing an immediate end to fossil fuel use.

Projected Drought Intensity in the U. S.

Though I believe the future for the Southwest is bleak, there is one small hope that the article contains. The Southwest could become a solar power generator that might give some of the people the financial means to survive the drought. Of course, this does nothing to protect nature and wildlife in the region. I’ve posted 43 discussions of climate-change induced drought in this blog. Click here to scroll through stories about the coming megadrought that can no longer be avoided.

“The nation’s two largest reservoirs, Lake Mead on the Arizona/Nevada border and Lake Powell on the Arizona/Utah border, were brim full in the year 2000. Four short years later, they had lost enough water to supply California its legally apportioned share of Colorado River water for more than five years. Now, 17 years later, they still have not recovered.

“This ongoing, unprecedented event threatens water supplies to Los Angeles, San Diego, Phoenix, Tucson, Denver, Salt Lake City, Albuquerque and some of the most productive agricultural lands anywhere in the world. It is critical to understand what is causing it so water managers can make realistic water use and conservation plans.

“While overuse has played a part, a significant portion of the reservoir decline is due to an ongoing drought, which started in 2000 and has led to substantial reductions in river flows. Most droughts are caused by a lack of precipitation. However, our published research shows that about one-third of the flow decline was likely due to higher temperatures in the Colorado River’s Upper Basin, which result from climate change.

“This distinction matters because climate change is causing long-term warming that will continue for centuries. As the current “hot drought” shows, climate change-induced warming has the potential to make all droughts more serious, turning what would have been modest droughts into severe ones, and severe ones into unprecedented ones.

The Colorado River is about 1,400 miles long and flows through seven U.S. states and into Mexico. The Upper Colorado River Basin supplies approximately 90 percent of the water for the entire basin. It originates as rain and snow in the Rocky and Wasatch mountains (Courtesy USGS).

How Climate change reduces river flow

“In our study, we found the period from 2000 to 2014 is the worst 15-year drought since 1906, when official flow measurements began. During these years, annual flows in the Colorado River averaged 19 percent below the 20th-century average.

“During a similar 15-year drought in the 1950s, annual flows declined by 18 percent. But during that drought, the region was drier: rainfall decreased by about 6 percent, compared to 4.5 percent between 2000 and 2014. Why, then, is the recent drought the most severe on record?

“The answer is simple: higher temperatures. From 2000 to 2014, temperatures in the Upper Basin, where most of the runoff that feeds the Colorado River is produced, were 1.6 degrees Fahrenheit higher than the 20th-century average. This is why we call this event a hot drought. High temperatures continued in 2015 and 2016, as did less-than-average flows. Runoff in 2017 is expected to be above average, but this will only modestly improve reservoir volumes.” –Brad Udall and Jonathan Overpeck (Much more: Climate Change Is Shrinking the Colorado River – Indian Country Media Network.)

NASA predicts global warming could dry Southwest America up

Posted on February 14, 2015 by GarryRogers

America the beautiful’s amber waves of grain could dry up and blow away if carbon emissions aren’t curbed, scientists predict.

Source: www.nydailynews.com

Plant Trees, Save Lives

Posted on August 3, 2014 by GarryRogers

Plant a tree, save a life

Jason G. Goldman Conservation This Week

Cottonwood Tree

“Air pollution is a serious problem in the United States. As a young child growing up in suburban Los Angeles, I remember days in which we were not allowed to play outside because of the air quality. Kids in other states had snow days, or so I was led to believe, but we had smog days.

“LA is doing better now. We don’t have smog days anymore. But air pollution still causes quite a bit of problems, both for public health as well as for the cost of health care. It’s been implicated in diseases like bronchitis, asthma, and other respiratory conditions. It impacts the cardiac, vascular, and even neurological systems. It leads to emergency room visits, hospital admissions, and sometimes morality. Kids miss school, adults miss work. Thankfully, we have trees. It is not an exaggeration to say that trees save both lives and money. That’s because they scrub the air of pollution.

The Clean Air Act required the U.S. Environmental Protection Agency to set air quality standards for six “criteria pollutants” that are both common throughout the country and detrimental to human health and welfare: carbon monoxide, nitrogen dioxide, ozone, lead, sulfur dioxide, and particular matter, which includes tiny little bits of stuff less than 2.5 microns in diameter. In 2005, particulate matter was implicated in some 130,000 deaths, and 4700 were related to ozone.

“But the truth is, those numbers could have been much worse if not for the trees. That’s according to a new study by U.S. Forest Service researcher David J. Nowak and colleagues, published this week in the journal Environmental Pollution.”

GR: Of course, in the Southwest we can’t plant more trees because the supply of water is dwindling. Over the past year, I’ve had to turn six large native cottonwood trees into wildlife woodpiles. Cottonwoods are phreatophytes whose roots draw on groundwater. If nearby wells withdraw so much groundwater that the water level sinks below the reach of the roots, the trees will die. The demand for groundwater where I live is growing along with the local population. More trees are dying and I will have to cut them this winter.