The following is an excerpt of the Browning Newsletter, a key source of information in describing the relationship between macro weather-related trends and their potential impact upon energy, commodities, and the wider global economy. To subscribe to her monthly newsletter, click here.
One of the major issues reported by the Browning Newsletter over the past two years is the huge impact of the changed Pacific on global weather and food supplies. Scientific research indicates a huge long-term cycle in the Pacific tipped in 2006 (some claim it changed in 1999), changing phases and changing the distribution of water temperatures throughout northern and tropical regions of the ocean. This, in turn, has changed air temperatures and air pressures, which altered global wind and weather patterns.
I recently gave a speech and power point presentation outlining some of the impact of these weather changes on food and agriculture. This article will show many of the slides. The changes in precipitation patterns created by the negative Pacific Decadal Oscillation (PDO) have made some agricultural areas more productive and others more drought-prone. The maps will show which areas of the globe will be facing major changes.
When precipitation shifts, so do farm belts. For the period of time that it takes agricultural societies to adapt to the changes, agricultural production suffers and food prices go up. Notably, now that the Pacific is in a cooler (and therefore drier) phase off the coasts of North and South America, the disruptive weather impacts of cool Pacific La Niñas are even greater. The droughts and soaring food prices during the 2007 – 2008, 2010 – 2011 and 2011 – 2012 La Niñas have shown how disruptive these weather changes can be.
The problem is that each phase of the PDO lasts for decades. Societies grow used to the “normal” patterns of precipitation and adjust their settlements and agricultural practices accordingly. Take North America as an example. Throughout most of the 1970s, ‘80s and ‘90s, the Atlantic’s long-term Atlantic Multidecadal Oscillation (AMO) was negative, producing a cool Atlantic and the PDO was positive, producing a warm Pacific off the West Coast. The warm Pacific waters heated the air overhead and warm air holds more moisture. The prevailing westerlies carried the moisture inland. The result was several decades of abundant rain throughout the Great Plains and Midwest.
The AMO changed in 1995 and warmed. This increased warmth, if it follows historical patterns, will continue for another twenty years with very few interruptions. Eleven years later, the Pacific tipped and should remain cooler off the West Coast for another 15 – 20 years. This has created drier conditions for most of the United States and a higher risk that large regions of the nation would experience drought during cool La Niñas.
Unlike the Atlantic, the cooler trend in the Pacific is interrupted every three to five years by an El Niño, which creates a flow of warmer water along the American coastlines. This change shifts precipitation patterns, often bringing lush moisture to drier regions. In the past, areas like California and Texas created numerous reservoirs to store the waters from these wet El Niño years for later use. Unfortunately, these reservoirs will not supply enough water to allow areas like California to live in the same style as they did in the wetter era. Expect major competition between urban and rural water users. Remember also the old California saying, “Water flows towards the money.” This does not bode well for agricultural water resources.
Notice that one Midwestern region tends to remain wet whether the Atlantic is warm or cool. Parts of Iowa, Nebraska and South Dakota continue to have good rains except during the occasional times when the Atlantic is hot and the Pacific is experiencing a El Niño. (This is why the combination of last summer’s hot Atlantic and El Niño conditions were so devastating.) Notice that this is the heart of corn country and the Midwestern soybean crop. Notice, also, that the Southeastern soybean belt is located in areas that usually have adequate moisture under the new climate regime.
The cattle industry is the most affected by the new climate conditions. From Kansas to Texas, dry weather and drought tend to hit this region about 20 – 30% of all years when the Atlantic is hot and the cold Pacific curbs the summertime Southwest monsoon. However, El Niños tend to reverse the trend and saturate Texas and parts of Oklahoma (but not poor Kansas). During the 1950s, the Southern Plains invested heavily in reservoirs and cattle ponds, storing water in the good years for the occasional drought. They also ran less cattle per acre. Using these tactics and fewer resources than ranchers have today, they fed the world.
Like North America, South America is trapped between the growing heat of the Atlantic and the cooler waters of the Pacific. While the PDO is currently defined as a northern Pacific oscillation, it strongly affects the tropics and appears to magnify the impact of cool La Niñas and cool MJOs. This in turn, as shown by tree ring studies, has long-term effects on South American climate and agriculture.
The main impact is on the Andean Republics along South America’s west coast – the lands that originally discovered and named the El Niño/La Niña phenomenon and have a 500+ Spanish written history of the cycle. During La Niñas the land regions are drier while the off shore waters become cooler, more fertile and fish become more plentiful. Historically, the dry conditions are most prominent in December, disrupting snow deposits in the Andes in the tropical and northern countries and agriculture in Chile. For centuries, the agricultural response has been for traditional farmers to plant a huge variety of crops, particularly types of potatoes, so that whatever weather evolves, they will have something to harvest.
Brazil and Argentina are increasingly investing in commercial one crop farming, which leaves their fields more vulnerable to weather cycles. The current cycles in the Pacific are bringing more rainfall to Brazil and less to Argentina. (Notice history shows these countries tend to trade off as continental powers.) Now it is Brazil’s turn as rainfall becomes less reliable for Argentina, particularly for its cattle country, the southern pampas (grasslands). Notice also that both countries (as well as Uruguay and Paraguay) have concentrated their farmlands in the regions with the most consistent rainfall. Still, history shows that these climate conditions have historically been linked with times of unrest in Argentina.
Changes in the PDO also affect other continents. In particular, Asia, with the strength of its monsoon seasons linked to the contrast between land and water temperatures, is affected by the shifting PDO. Typically during the negative phase of the PDO, the waters off the coast of Asia, particularly East Asia, are warmer, increasing the strength of the monsoons affecting Northern and Central China and most of India, while the monsoon impact around the South China Seas and portions of western Asia including Pakistan and parts of the Punjabi wheat belt weakens.
Most rice regions are in areas that will either accept more rainfall or remain the same. Southeast Asia, the world’s major rice exporting regions are particularly immune from impact by the PDO (but not from El Niños). In China its corn, soybean and wheat areas are in areas that are receiving better moisture. (Indeed, one of their main problems is post-production – drying the crops sufficiently for storage. It should be noted that most of the northern regions of India that are drier during a negative PDO, experience most of their drier condition in winter. This is one of the reasons that there is reduced snowpack in the Southern Himalayas while most of India is producing enough crops for export.
*The drier weather in most of Northern India is less winter moisture. Historically, summer monsoons usually supply good rainfall for crops.
Remember, the Pacific is not the only major climate force shaping Asian weather. The Indian Ocean also goes through cycles that can temper or increase the impact of the Pacific. The same holds true of Australia.
The Indian Ocean Dipole, which switches warmer Indian Ocean temperatures east and west, interacts with the PDO’s impact on El Niños (which dry Australia) and La Niñas (which bring heavy rains and even floods.) Overall, the combination of the growing Indian Ocean warmth and the negative PDO, which weakens El Niños and enhances La Niña, brings more precipitation for Australia, which is excellent for the nation’s wheat crop and livestock. Unfortunately, this also enhances the danger of wildfires during dry seasons, since there is more brush growth. However, the overall outlook is good for Australian agriculture and its ability to feed Asian markets.
Europe is relatively immune from the impact of the PDO, but not the growing warmth of the Atlantic.
The general impact of the heating Atlantic has been to create more extreme summer and winter weather for the European continent. In particular, it has increased the probability of hot, dry weather for Southern Europe during the growing season. In other words, not only are these southern nations facing increasing economic woes, their agriculture is facing increasing difficulties. We saw this last year as the corn and oilseed crops of Spain, Italy and the Balkans took a hard hit due to heat and drought.
Africa is also affected by the Atlantic warming. As noted in February’s issue, the increased monsoons are improving agriculture in the Sahel south of the Sahara, while the desert heat is increasingly devastating most of the nations along the Mediterranean Sea.
Overall, the impact of the changed PDO and hot Atlantic on global climate is being reflected in food prices. Middle latitude grains, like corn, wheat, barley and oats, have reduced production and soaring prices during cool La Niñas. We see a similar pattern in middle-latitude oilseed crops, such as soy, canola and sunflowers. Meanwhile tropical crops, such as rice and palm oil show less impact from the changed PDO. But, as the maps show, the negative impact on middle-latitude crops are not evenly distributed. Some areas, like Northern China and parts of the American Midwest, prosper with the change in climate.
Typically, it takes about a decade for societies to adjust to the “new normal” created by the shifts in the Pacific. They migrate, originally to other farmlands and more recently, as a source of labor, to cities or other neighbors. They change crops or, with livestock, adjust acreage and breeds. During the 1970s, many traditional societies accepted the “green revolution” and currently some are increasing their use of genetically modified seeds. We are in the middle of one of these times of adjustment, but history can show us how to ease the transition.
Source: Browning Newsletter