The Historic Drought of 2012-????

Featured Image: “Shasta Lake low” by Bobjgalindo – Own work. Licensed under GFDL via Wikimedia Commons

By now, you have no doubt heard that the state of California is in the midst of a drought. To date, the drought has gotten serious enough that news outlets everywhere are talking about the state’s pending water catastrophe. The Governor’s water restrictions already tell you how this is going to affect your day to day life. As avid hikers, we cannot avoid seeing the impacts of the drought at virtually every turn. In small ways and large ways, the drought is changing the landscape – sometimes literally – and we will likely see and feel the impacts long after the current drought is over.

 

The Historic Drought of 2012-????

CA-Drought-Monitor-3-31-15

Our current drought is not a run-of-the-mill California drought. As of April 1st, 2015, the average snowpack for the Sierra Nevada mountains was at 5% across the entire range. One year ago during the final snowpack survey for 2014, the Sierra snowpack stood at 14% of average. In 2013, the final snowpack reading in May showed that snow levels were at 17% of normal. 2012- the year when our current drought began, was slightly better at 30% on the March 1st reading. That is four straight years with less than a third of the average Sierra snow pack. Put in other terms, the late season Sierra Nevada added up over 4 years equals less than one average year of snowfall spread over a four year period.

More than 60% of California’s water supply  comes from the Sierra Nevada, and that water is used not just to water our golf courses and lawns. It grows our produce, helps our livestock to survive, and, crucial for hikers everywhere, it allows our myriad state ecosystems – which feature some of the oldest, largest, and rarest living things on the planet – to survive. Furthermore, the snowpack tends to melt slowly over the course of Spring and early Summer, which means that a steady stream of water continues to replenish reservoirs (most of which are about half-full at the moment) and feed thirsty plants until early fall, when precipitation begins again. This year, the snowpack will likely be gone by May.

In most areas of the state this year, rainfall rates have been slightly closer to average, with the Bay Area doing particularly well. However, most other regions – specifically Central California – remain dry. SoCal is no exception.  The city of Los Angeles has currently received 6.51″ of rainfall for the 2014-2015 season, which is around 40% of its yearly average. San Diego is doing better with 6.23″ out of its usualy 10+ inches – good for around 60% of the city’s yearly average. Those totals will likely increase slightly before the water year ends on June 30th, but it is highly unlikely that either city will reach average precipitation for the 4th year in a row.

At the same time as the state has received diminished precipitation, record-breaking heat has reduced the snowpack to a mere shadow of its historic averages. In 2014, the overall average temperature in California was 4.4 degree fahrenheit warmer than the 20th century average temperature, breaking an all-time record as the warmest year in California’s recorded history. 2013’s state average temperature was 1.4 degrees above average, making it the 12th warmest year in California’s recorded history. The state did not rank significantly warm in 2012, although it should be noted that 2012 was the warmest year in the continental United States’ recorded history at 3.4 degrees above average. 2015 is proving to be no exception. Los Angeles saw its 6th warmest January in recorded history (which is 162 years, according to NOAA’s database). Summaries for February are currently unavailable, but February was likely also one of the warmest months in the history of the state. San Diego saw a high 86 degrees on Thursday, February 12th. In Los Angeles meanwhile, the first 26 days of the month were warmer than average, with temperatures topping out at a spectacular 88 degrees on February 13th. March turned out to be no different with a high of 91 degrees on Saturday, March 14th.

 

The Culprit

Sierra_snowpack_and_California_State_water_project_allocations

The combination of extreme heat and historically low precipitation totals adds up to what is being called the worst drought in the state’s recorded history, and possibly the worst drought the state has experienced since the 9th century – at least according to records gleaned from tree rings. Climatologists and meteorologists have been following the precipitators for the drought closely, and they have pin-pointed the primary culprit as something known colloquially  as the Ridiculously Resilient Ridge – a term coined by Daniel Swain, whose blog Weatherwest.com should be required reading for anybody interested in the climate, weather, and environment in California.

To understand the ridge, you’ll need a bit of a primer on how the state’s winter weather works (bear with me if you already know this stuff). There are enormous rivers of high-speed winds flowing through higher levels of the atmosphere known as jet streams. The jet stream that most affects us – especially during winter – is the Northern Polar Jet Stream, which circles the globe in the higher latitudes. In the winter, the Northern Polar Jet dips to lower latitudes, often flowing directly down the coast of California out of the Gulf of Alaska. This jet stream, along with the subtropical jet at the lower latitudes, is responsible for moving around two different types of air masses from west to east. It’s worth noting that the Jet Stream has weakened in recent years, thus diminishing its ability to push air masses around.

One type of air mass, called a low pressure system, generally features unstable, moisture-laden, colder air. These low pressure systems are the source of our storms, and when the polar jet dips into lower latitudes, it passes through the usually cold Gulf of Alaska, where low pressure systems tends to originate. Conversely, high pressure systems are warm, stable air masses that tend to produce fair weather and warm temperatures. In the state’s usual winter climatic scheme, the jet stream produces a progressive pattern in which a parade of low pressure and high pressure systems pass over the west, bringing alternating periods of heavy precipitation and mild, fair weather.

Occasionally, a high pressure system sets up shop in the northeast Pacific and will not budge for several weeks. Brief periods of drought in the winter are common and expected for California, so a temporary blocking high pressure system is not a significant event by itself. However, the last three years have witnessed massive, high-altitude, high pressure systems that have established themselves over the Gulf of Alaska – partially fueled by abnormally warm water temperatures up and down the west coast. During the past three years, the weakened Jet Stream has frequently found itself unable to push through this obstacle, and like any current faced with an immovable obstacle, the jet will usually elect to go around. The common pattern for the jet stream in this setup is to go up and over the ridge into the arctic circle, after which it will flow down the eastern side of the Rocky Mountains, pulling frigid, Arctic air down into the eastern two-thirds of the country. This situation – called the Arctic Dipole – is the reason why it can be 21 degrees warmer than average in Los Angeles and 16 degrees below average in Boston on the same day (February 13th). The winter of 2013-2014 saw the most extreme dipole in recorded history, which also coincided with California’s driest year in recorded history.

The crucial factors here are the ridge’s resiliency and the recent weakening of the Northern Polar Jet Stream. As I mentioned before, a typical blocking ridge will usually last a few weeks. The ridge of 2013-2014 essentially stayed in place through the entire winter, with a brief respite in late February and early March. Such a ridge either deflects incoming low pressure systems into Alaska, or it will cause them to disintegrate completely. Medium-range forecasting models this year have consistently shown massive Pacific storms in the 7-14 day outlook only for meteorologists to watch the storms vanish on approach of the ridge. This scenario is the equivalent of Spud Webb trying to dunk over Manute Bol.

 

A Thirsty Landscape

800px-Southern_California_Fires_(3869161421)

Southern California Fires” by Rennett Stowe from USA. Licensed under CC BY 2.0 via Wikimedia Commons.

While the state frets about how California will get its water during what is highly likely to be a warm summer, we at Modern Hiker fret about the state of the environment with which we have become so intimate. Drought has a direct effect on our ecosystems, especially in combination with other factors like heat, natural pests, and inconsistent (or poorly funded) forest management practices. Following the droughts in the early 90’s, San Diego County’s coniferous forests had suffered heavily from attacks by bark beetles, which tend to overwhelm trees during times of drought. The damage to the trees resulted in heavy detritus on the forest floor in the form of dead trees. In October of 2003, the 280,000+ acre Cedar Fire roared through San Diego County, incinerating 95% of the forest at Cuyamaca Rancho State Park, which itself accounted for about 20% of San Diego’s coniferous forest. Four years later, the combined Poomacha and Witch Creek Fires wiped out another substantial percentage of Palomar Mountain’s forest. In a five year period between 2002 and 2007, San Diego County lost 51% of its coniferous forest. Let that sink in for a minute: A county the size of Connecticut and Rhode Island combined lost half of its coniferous forest in 5 years.

You will see the same story of megafires repeated across the state. Twelve of the 20 largest fires in the state’s history have occurred since 2000. Angelenos are constantly reminded of the devastation of the 150,000 acre Station Fire, while the Yosemite region suffered from the state’s second largest fire in recorded history (the 257,000 acre Rim Fire) in 2013. We must caveat by saying that fires don’t always get this big specifically because of drought; there are always other elements at play. However, a dry forest burns more readily than a wet one, so there’s no denying the effect of drought. It’s impossible to say what kind of megafires might be waiting for us in the future, but it is all but certain that dead and dry living fuels across the state will be at dangerously high levels so long as the drought continues. Furthermore, the Ridiculously Resilient Ridge appears to be a factor in the fire season occurring earlier than normal; the 2013 Springs Fire (which incinerated most of Point Mugu State Park) and the 2014 San Diego County Firestorm both occurred in early May during Santa Ana wind events at a time when the weather is usually dominated by heavy marine layer.

The state’s trees are likely to be the primary victims, with the Sierra Nevada and coastal big trees being the figurative canaries in a coalmine. California is world famous for containing some of the largest and oldest trees on the planet, including the giant sequoia and the coast redwood. In addition to those more resilient species, the state contains superlative (and highly sensitive) specimens of pines and firs that are dying off rapidly. California contains the two largest pine species – the sugar pine and the ponderosa pine – which can both grow to over 250′. The state also contains red and white firs, which both also top 200′. When there is abundant water, these trees produce sap that keeps pine beetles – a naturally occurring pest – at bay. Throughout the current and recent droughts, all of these species are succumbing to pine beetles at accelerated rates.

Conifers are particularly sensitive, but other species of trees are not immune. Since the late 1990’s, San Diego County’s oak trees have suffered from an onslaught of the gold-spotted oak borer – an introduced bark beetle from Mexico to which native oaks have no natural defense. As oaks use the same defenses against pests as conifers, drought-stress makes oak more susceptible to beetles. As a result, large swaths of oak woodlands across San Diego are now dying at an accelerated rate. Oak trees sink deep roots into subterranean water tables, and as aquifers are depleted, oak trees lose their water source, leading to more die-off. Like its famous conifers, California also contains some of the largest and most beautiful oaks on the planet, including the valley oak, coast live oak, and black oak. The drought-stress comes at a time when many of California’s oaks are already under attack by continued urban and suburban development.

 

Accelerated Climate Change

800px-Enso-global-temp-anomaliesEnso-global-temp-anomalies” by NOAA. Licensed under Public Domain via Wikimedia Commons.

So far, I’ve side-stepped the elephant in the room when it comes to discussion about  unusual and unprecedented environmental events. We are well aware that climate change remains a controversial subject despite the overwhelming evidence from a number of respected scientific sources that indicate that climate change is a fact that will undoubtedly continue and possibly increase so long as we burn fossil fuels as our primary energy source. Scientists estimate that Arctic sea ice will reach its lowest extent in recorded history, which is more significant than being bad news for polar bears. Again, the loss of arctic sea ice appears to be weakening the polar jet stream, thus reducing its ability to break through blocking ridges while simultaneously leading to increases in extreme weather events like record-breaking snow in the east coast, over 90% of the Great Lakes being covered in ice in 2014, and record-breaking droughts in the west.

Climate change is currently shifting the distribution of plant species across the state, which results in stand-replacement of the original species by more drought and heat-tolerant species from the lower elevations. This shift is already in evidence from the climate’s long term warming pattern from the last major ice age, which has resulted in the formation of numerous botanical “sky islands” in the local mountains, wherein previously abundant ecosystems such as mixed-conifer forests retreated to the mountain tops. However, the change has accelerated rapidly (helped along by over-development), as evidenced by the rapid loss of numerous ecosystems across many parts of Southern California.

If you accept that climate change is a fact and will continue, and if you accept that the current drought’s intensity and duration are a possible symptom, then the big take away is that this may be a taste of the future. Climate scientists project that average Sierran snow packs will be at 20% of their current average by the year 2100. The potential for California’s average temperature to rise 4.5 degrees over the next 85 years could spell the potential end for a number of ecosystems that we take for granted, including endemic species famous the world over like the Giant Sequoia, Coast Redwood, Torrey pine, Bristlecone pine, and the Joshua Tree. But perhaps the most maddening thing is that, on the surface, there appears to be so little that we can do to stop the drought. We can’t make the atmosphere produce more rain, just as we can’t shoo the Ridge out the door (although I’m sure the East Coast would be happy to take it off our hands next winter).

If you have spent a decent amount of time hiking in Southern California over the last four years, you will notice that things don’t seem the same. Ponds have turned into fields of baked mud. Hundred year old pines and oaks are succumbing to bark beetles. Streams are drying up. Thousands of acres of one of the planet’s greatest forests get incinerated every year. The temperatures are 20 degrees warmer than average. It’s a lot like watching one of your best friends die from an extremely slow cancer and feeling that there’s nothing you can do about it. We hope that this article inspires you to greater awareness and perhaps even taking action. You are almost certain to feel the drought in your wallet this summer due to diminishing water supplies. However, if you are a nature lover, chances are the drought will hit you where it hurts the most when you hear about the next megafire devouring a large swath of California’s wilderness or when Sturtevant Falls is the merest trickle this July.

In the past, Modern Hiker and Modern Hiker readers have made great efforts to stem defacement of environments by vandals. On this small scale, we fight a worthy battle and make a large difference in sending a message that the environment matters. Now it is time to begin thinking of how we can take the fight to the largest assault on the environment in human history. There are a number of different things that the average person can do from personal conservation choices through grass roots activities to actively petitioning congress to not only stop trying to deny the problem but actually pass legislation that does something about it.

These things are only the beginning, as many of these potential solutions reflect what the average person can do, but not what society at large can do. Our society is built on a foundation of fossil fuels, so large scale changes to change the direction that global patterns are moving in appear to be dependent on our ability to reduce dependence on fossil fuels. With greenhouse emissions projected to double within the next 50 years, a massive change would have to occur sooner rather than later. This change becomes less and less likely the longer that climate change denial movements are able to sustain themselves; this occurs largely due to funding from corporations that have a vested interest in maintaining the status quo, as Exxon Mobile and the Koch Brothers among others provided $558 million in funding to the Counter Climate Change Movement between 2003 and 2010. The current congress is showing no signs of wishing to change. 

The fact that Congress and some corporations are resisting change is not particularly surprising, given that historical precedent is for entities in power to do what it takes to remain in power. It does not behoove ExxonMobil to acknowledge that its business model is destroying the planet, nor does it behoove a Congressperson to acknowledge global warning when it would damage his relationship with the financial backing that put him or her in power. Just as countless other people in history learned that they cannot always count on their leaders to do the right things, we – the people being “governed” – must embody, support, demand, propose, and insist upon the sort of change we’ll need to prevent not just more droughts like this one but the potential global catastrophes that the trends presented here suggest.

 

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