While global warming features prominently in Myrtle’s gardening lexicon, the largest climate impact on vegetable growers comes from a different phenomenon sometimes in the news – the El Niño Southern Oscillation (ENSO) Effect. In short, for Texas, years featuring El Niño are moderately cooler compared to average, and much wetter. Years featuring La Niña are aggravatingly warmer, and much drier. In addition, El Niño has the tendency to thwart tropical storm development, while La Niña tends to encourage it.
El Niño occurs when the Pacific Ocean surface temperatures are warmer than normal in certain zones near the equator associated with changes in atmospheric patterns, and La Niña is the description given to the phenomenon of cooler than normal temperatures in the same regions. Neither is good or bad in isolation – they each have more or less opposite effects in different places. El Niño may bring lots of rain to the American southwest, for example, but it causes drought (and sometimes famine) in parts of Asia and Australia. On the other hand, El Niño causes increased wind shear in the Atlantic, reducing hurricane development, while La Niña causes reduced wind shear, making Atlantic hurricanes more likely.
Obviously, while weather impacts elsewhere affect other people in sometimes devastating ways, it is nevertheless true that as a general rule, Texas gardeners do better in El Niño years than otherwise, and we suffer harsh conditions during La Niña.
The recent drought is coming at the tail end of a La Niña. To say that the Niña event “caused” the drought would be, perhaps, a bit of an overstatement, but it certainly did not help. Even when ENSO-neutral conditions were reported starting in May/June, the Niña effects have lingered, and so has the drought. This is part of the self-sustaining pattern of high temperatures and drought – heat bakes the soil, making moisture less available, and ensuring that the soil retains still more heat. The best way to break the cycle is to add a significant amount of moisture in the form of rain from a tropical storm, which is a “solution” replete with its own dangers.
And now, as we bake in the dog days of August, comes word from the Climate Prediction Center in the form of their 4 August 2011 El Niño/Southern Oscillation (ENSO) Diagnostic Discussion, that “ENSO-neutral is expected to continue into the Northern Hemisphere fall 2011, with ENSO-neutral or La Niña equally likely thereafter.”
What does this mean, exactly?
For starters, we have a small window of opportunity to receive normal (or at least normalish) rainfall, starting in September and running for a few months, up to about December or so. Otherwise, we can expect drought conditions to continue probably through at least next summer.
This second La Niña event is not altogether unexpected; historically, a weaker “little sister” Niña frequently accompanies a stronger first wave. This makes sense if you picture what we are really talking about when we discuss the ENSO phenomenon – we are looking at an area of energy, more or less, in the form of either lower (Niño) or higher (Niña) temperatures in the water roughly riding the equator in the Pacific, from Asia to the Americas. Water moves in waves, right? And when is the last time you ever saw a body of water with just one wave in it? So this is not a static phenomenon – ENSO undulates, more or less, like water in a bathtub after you plunk a baby down in the middle of it. (It’s about that messy, too, but that’s a whole other discussion…)
The second Niña will probably not be as strong as the first, which is good news for people living on coastlines – Summer 2010 saw the development of a large number of exceptionally powerful hurricanes, assisted by Niña conditions. Only shear dumb luck kept them away from land, because landfall from any of last summer’s hurricanes would have been a major calamity. This summer still has the chance to produce some Katrina-esque storms, even though we have returned to ENSO-neutral at the moment, meaning atmospheric conditions are basically “normal” instead of being overly hurricane-friendly, as is true in Niña conditions.
However, as it relates to drought, a weaker Niña event won’t really help much. This is because one of the primary drivers of our drought is now the lack of soil moisture from having been in drought for so long – literally, we are more likely to be in drought because for so long we have been in drought. And dry soil warms up much more quickly than moist soil, so in addition to having no rain, we can expect a repeat of this year’s record temperatures, too. A strong Niña would be worse than a weak one, but not really by all that much.
The City of College Station is starting to discuss the possibility of water rationing, which is good, we suppose, because water use is at all time high levels. Water rationing probably should have started long before now, though, particularly given that this is not going to be a “one and done” water shortage. The time for short-term thinking has been over for many, many moons. Delaying rationing rules until we reach the limits of available water guarantees that rationing will cause maximum pain to everyone involved; coming up with smarter water use rules before reaching crisis point makes much more sense.
We are not the only community facing this problem; the time has come to get serious about water use and reuse. We need revised city codes making it easier for residents to recycle gray water; we need increased subsidies for rainwater collection. Lawns should be discouraged; xeriscaping should be incentivized. Low-flow toilets (or even composting toilets), low-flow showerheads, and a host of other water saving gadgets ought to be subsidized. Dishwashers should be sent the way of the Edsel – handwashed dishes are not only cleaner, more water and energy efficient, but also have the advantage of not throwing a lot of chemicals into the air you breathe.
It will eventually rain again. And one of these years, we will probably even get too much rain – it may be difficult to remember such times, but they have happened before, and will come around once more. But the new normal, at least in Myrtle’s neighborhood, is hot, and dry, and plenty of it. The sooner we adapt to this reality and move on, the better.
Happy farming!
El Niño occurs when the Pacific Ocean surface temperatures are warmer than normal in certain zones near the equator associated with changes in atmospheric patterns, and La Niña is the description given to the phenomenon of cooler than normal temperatures in the same regions. Neither is good or bad in isolation – they each have more or less opposite effects in different places. El Niño may bring lots of rain to the American southwest, for example, but it causes drought (and sometimes famine) in parts of Asia and Australia. On the other hand, El Niño causes increased wind shear in the Atlantic, reducing hurricane development, while La Niña causes reduced wind shear, making Atlantic hurricanes more likely.
Obviously, while weather impacts elsewhere affect other people in sometimes devastating ways, it is nevertheless true that as a general rule, Texas gardeners do better in El Niño years than otherwise, and we suffer harsh conditions during La Niña.
The recent drought is coming at the tail end of a La Niña. To say that the Niña event “caused” the drought would be, perhaps, a bit of an overstatement, but it certainly did not help. Even when ENSO-neutral conditions were reported starting in May/June, the Niña effects have lingered, and so has the drought. This is part of the self-sustaining pattern of high temperatures and drought – heat bakes the soil, making moisture less available, and ensuring that the soil retains still more heat. The best way to break the cycle is to add a significant amount of moisture in the form of rain from a tropical storm, which is a “solution” replete with its own dangers.
And now, as we bake in the dog days of August, comes word from the Climate Prediction Center in the form of their 4 August 2011 El Niño/Southern Oscillation (ENSO) Diagnostic Discussion, that “ENSO-neutral is expected to continue into the Northern Hemisphere fall 2011, with ENSO-neutral or La Niña equally likely thereafter.”
What does this mean, exactly?
For starters, we have a small window of opportunity to receive normal (or at least normalish) rainfall, starting in September and running for a few months, up to about December or so. Otherwise, we can expect drought conditions to continue probably through at least next summer.
The second Niña will probably not be as strong as the first, which is good news for people living on coastlines – Summer 2010 saw the development of a large number of exceptionally powerful hurricanes, assisted by Niña conditions. Only shear dumb luck kept them away from land, because landfall from any of last summer’s hurricanes would have been a major calamity. This summer still has the chance to produce some Katrina-esque storms, even though we have returned to ENSO-neutral at the moment, meaning atmospheric conditions are basically “normal” instead of being overly hurricane-friendly, as is true in Niña conditions.
However, as it relates to drought, a weaker Niña event won’t really help much. This is because one of the primary drivers of our drought is now the lack of soil moisture from having been in drought for so long – literally, we are more likely to be in drought because for so long we have been in drought. And dry soil warms up much more quickly than moist soil, so in addition to having no rain, we can expect a repeat of this year’s record temperatures, too. A strong Niña would be worse than a weak one, but not really by all that much.
The City of College Station is starting to discuss the possibility of water rationing, which is good, we suppose, because water use is at all time high levels. Water rationing probably should have started long before now, though, particularly given that this is not going to be a “one and done” water shortage. The time for short-term thinking has been over for many, many moons. Delaying rationing rules until we reach the limits of available water guarantees that rationing will cause maximum pain to everyone involved; coming up with smarter water use rules before reaching crisis point makes much more sense.
We are not the only community facing this problem; the time has come to get serious about water use and reuse. We need revised city codes making it easier for residents to recycle gray water; we need increased subsidies for rainwater collection. Lawns should be discouraged; xeriscaping should be incentivized. Low-flow toilets (or even composting toilets), low-flow showerheads, and a host of other water saving gadgets ought to be subsidized. Dishwashers should be sent the way of the Edsel – handwashed dishes are not only cleaner, more water and energy efficient, but also have the advantage of not throwing a lot of chemicals into the air you breathe.
It will eventually rain again. And one of these years, we will probably even get too much rain – it may be difficult to remember such times, but they have happened before, and will come around once more. But the new normal, at least in Myrtle’s neighborhood, is hot, and dry, and plenty of it. The sooner we adapt to this reality and move on, the better.
Happy farming!
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