One of the more interesting research results I have read recently is an attempt to link La Nina with major flu pandemics in human history. I am unsure why, but I instantly developed a heap of skepticism about this theory/study. I don’t have access to the full paper so I can’t evaluate the results as in depth as I would like, but I will opine anyway.
On a superficial level, this theory might seem to make common sense, in that colder weather is associated with a higher incidence of flu and colds. La Nina is a cooler than normal surface water pattern in the tropical Pacific Ocean so perhaps it is also linked with colds and flu. Well, it is certainly not that simple when it comes to the spread of viruses.
The authors of the study speculate that La Nina changes the flight patterns of birds migrating around the globe. Birds carry viruses. During a La Nina, their altered migratory pattern puts them in areas where they can pick up different flu viruses. These viruses then mix and mutate within the birds creating a “bad flu” which eventually causes a pandemic in the human population of the world. The research claim that four widespread pandemics in the last 100 years happened around the same time that La Nina was occurring in the Pacific Ocean.
The Current La Nina, as of January 8th
I think it is just a chance association – a case of fitting data to a pattern without clearly delineating a cause. Here is why:
There are many weather patterns that affect the movement of birds and other migratory animals. The El Nino/La Nina cycle is an important one, but there are many other ocean and atmospheric patterns that could fit the bill. Even long droughts or significant floods can force animals to move hundreds or thousands of miles out of their normal range. Also, different strains of flu spread across the globe every year, not only during times of La Nina. Why would one ocean pattern (La Nina) cause more widespread pandemics than others that similarly cause disruption in animal/bird movement?
On a slightly different note, I have always wondered about the spread of flu and how we tackle the problem. In the absence of a sure-fire 100% technological/medical cure or antidote for the flu, I think it is a somewhat positive thing that viruses spread around the world. I like to think of us as having two immune systems, an individual one and a social one. The social immune system is all of ours, linked through the transmission of viruses.
In the distant past, humans did not travel the globe. When people did start moving large distances they brought “unknown” diseases to new lands. These diseases wiped out indigenous people who did not have any immune resistance built up to the new pathogens. It is estimated that over 90% of Native Americans in the U.S. died because of disease, not because European immingrants directly killed them. In today’s world, millions of people travel from one end of the globe to another every single day. There isn’t much chance for a particular virus to develop/mutate for decades or hundreds of years in a small isolated population in a distant corner of the earth, only to wreak havoc on the rest of the population once it is let out. Most viruses mutate and spread rather rapidly. They don’t have a great chance of picking up several deadly mutations over a long period of time. It would seem that minor mutations occur every year and once the “new” non-lethal viruses spread around the world (the annual flu season) we all gradually pick up immunity – through our social immune system. That is why I don’t mind getting the occasional flu or cold. Like the old saying goes, if it doesn’t kill you, it will only make you stronger. I am afraid that if viruses did not spread around, then we would be more susceptible to deadly versions in the future.
Of course, I am middle-aged, so I do not have as much to fear from the flu as the elderly. If I was older, I might be more germ-phobic. In the end, I definitely support the development of powerful technological/biomedical tools to eradicate all human diseases, pathological or otherwise. Until that point, the constant transmission of non-lethal viruses might be preventing the next big lethal pandemic. (just my little thought/theory about the flu I wanted to share, thanks for your attention, feel free to disagree)
Staying on the subject of La Nina, it is well known that it usually brings about lower than normal precipitation in the southern U.S., which is why folks in Texas were not looking forward to this Winter season. Luckily, many parts of Texas have received significant rain over the last couple of months so the drought is not as bad as earlier this year, but with La Nina expected to persist for another month or two, the situation could deteriorate. Check out the latest U.S. Drought Monitor here.
Lucky for us here in Wisconsin, below normal precipitation does not affect our livelihood too much. Snowmobiling has been non-existent for 95% of the state. Cross country skiing has been a little rough as well. But for food and water purposes, winter precipitation is not as critical as Spring and Summer precipitation. So even though 40% of the state is currently “abnormally dry” and it would be nice to pick up a couple feet of snow before Spring, rainfall will be the key once we get into April and May. That is when we will need it the most.
And just for the heck of it, here is a little article I read recently about the “Check Engine” light all cars are equipped with. It isn’t weather or science related but it reproduces my opinion on the subject matter quite well. My “Check Engine” light story is this: The only new vehicle I have ever bought in my life came with a 60,000 mile full warranty. At about 60,213 miles the check engine light came on. I thought the timing was rather suspicious. When I took the car into the shop, there was a several hundred dollar list of repairs suggested - most were fixes or replacements of parts I have never heard of – and I know a bit about cars. Suffice it to say, the car was running fine so I didn’t get anything fixed. I have been driving it 5 years hence, all the while with the check engine light on, and it still runs just fine (I don’t recommend this practice, just relating a story here). Do any readers out there have any check engine light stories?
Have a fine Thursday! Meteorologist Justin Loew
Posted under Drought, ENSO Update, Oceans, Uncategorized
This post was written by jloew on January 19, 2012