Heat, Drought, and Watershed Storage

Blog #80  6-30-21  CaliforniaGeo

A Heat Dome Covered the Pacific Northwest- 

This week, Portland, Oregon became a standout for shattered record temperatures, causing a re-shuffling of high temp U.S. cities.  It was a tough string of days for a region where less than a third of residences have air conditioning.  It  was 117° in Portland, Oregon on Monday June 28th, a seven degree bump from the record set just a day before.  There were power outages, buckled road pavement, melted transit electrical cabling, sold out fans and portable air conditioners.  Many suffered through the night in living spaces approaching 90°.  And it didn’t do much good for the U.S. Olympic Trials in nearby Eugene, either.

It was a blazing reminder to those who suffered through it and the rest of us observers as we came face-to-face with climate change.  Not far across the U.S. border, Lytton, British Columbia set a new Canadian record of 118°.  The heat dome of extremely high pressure was formed by a wandering Jet Stream.  It was unique, like the Polar  Vortexes of recent years, and both have increased.

While many citizens may prefer to look at climatic averages to reman less concerned, it should be noted that while the averages move only a bit over time, the extremes increase in severity.  This is the kind of thing that changes the boundaries of arable land for agriculture, the availability of water, and the likelihood of human migration against all discouraging factors opposing it. 

Ocean temperatures are partly responsible for steering the Jet Stream.  They have absorbed lots of heat from the atmosphere during global warming, and we have seen the disappearance of Arctic sea ice and the separation of ice islands from Antarctica.  As oceans warm, historic patterns of the Jet Stream shift, and this brings weather extremes more often, with serious effects for plant and animal life.

Drought-

There is a localized relationship between high atmospheric heat and drought.  For example, the hotter the temperature, the greater is plant transpiration of water into the air and the lesser is the chance of rainfall.  This results in  less ground water to feed the water table, its surface streams, and lakes / reservoirs below.  The less water that’s available for transpiration lowers humidity and increases temperature.  In Quincy, California’s recent hot weather, the daytime relative humidity outside has been 17%.  Plants will respond to that with extra transpiration to stay cool enough for survival.

Government agencies have long been observing and studying drought and its effects.  Certainly we know that droughts cause woody fuels to reach dryness levels that are unprecedented; arriving earlier.  And we have recent evidence that droughts contribute to record-length wildfire seasons and acreage burned.  California’s new record was 4.2 million acres of burned land in the 2020 dry season.  The loss of life and property were very serious, and we haven’t yet seen the end of roiled homeowner insurance costs or denied coverage.  

Like fires and extreme temperatures, we can see the effect of climate shifts from lowered water levels in our reservoirs. 

These bathtub rings are wide and represent serious deficits in water storage.  However, every foot of drop here is unequal.  The storage capacity of Mead (at 56 million acre feet) is 16 times the size of Oroville and 10 times that of Lake Shasta, California’s largest.

When considering repeated or prolonged droughts and serious climate changes there is an obvious question concerning the reservoirs above.  Will any or all of them refill to capacity?  At least in the case of Lake Mead, that seems remote.  It has been shrinking for years.

Progress toward Solutions-

We know that greenhouse gases must be drastically reduced.  Methane and carbon dioxide are the greatest culprits.  Electrifying transportation and buildings can take the biggest bite out of these.  A tax on carbon would also help.  Electricity is something we can make renewably, and it is becoming cheaper than traditional generated sources.  Getting rid of carbon and methane emissions not only protects against global warming, it also improves human health, thereby extending lives and reducing medical costs,

The HVAC Equipment Supporting Electrification-  

With the exception of fully passive solar designs for buildings’ interior heating and cooling, home electrification will occur through refrigerant compression—better known as heat pumps.  Heat pumps do what their name implies—they move heat from one place to another for the benefit of your building, just like your refrigerator does.  Except that a heat pump works in two directions.  It provides heat when desired and can remove it, too.  

The most common version of a heat pump is known as an air-source unit.  It concentrates and delivers heat from or rejects it to a reservoir of outside air.   The lesser known type is the ground-source (aka “geo”) heat pump.  It performs its work against an underground thermal reservoir with fixed temperatures, unlike the daily and seasonal fluctuations found in air.

I’ve been fortunate for the last 6.5 years to have lived in a carbonless geo heat pump and solar PV equipped home that has hit cost zero three times and zero net energy twice.  The worst year’s performance produced a monthly equivalent billing of $6.34. 

The sooner we get busy with de-carbonization, the less severe worldwide climate change will be.

—Bill Martin