El Niño causes droughts in northern South America, killing cattle, harming water-dependent wildlife and forests, and slashing hydroelectricity output. It is often followed by La Niña. That’s not to say that floods only happen in La Niña years or droughts only happen with El Niño, but rather that the converse is true: La Niña years almost always bring floods and El Niño almost always brings drought to northern South America, and other disruptive effects elsewhere.
1988 La Niña Hurricanes Joan and Gilbert both affected northern South America, as did August flooding from the Magdalena river in Colombia to Ciudad Guayana, Venezuela.
1997-98 El Niño drought throughout northern Andes, cutting Peru’s growth by 2.8 percentage points and causing damages in Ecuador equal to 15 percent of GDP. Foreknowledge helped little.
1999 La Niña Caused the Vargas Tragedy, which may have killed 20,000 people in Venezuela, in December 1999.
2007-10 El Niño drought that slashed power production in Venezuela, forcing the country to import fuel oil and food, slow output from the steel and aluminum industries, and start water and power rationing that never went away. Caracas reservoirs almost dried up.
2011 La Niña Catastrophic flooding in Colombia.
Click for interactive chart
El Niño may well break the lengthy drought in Chile which would be mostly a good thing for humans, cattle, sheep, lettuce, glaciers and mining projects. (Click that link if you want to learn some good Chilean Spanish.) But further north, it could start another 2- or 3-year cycle of climatic instability. I hope the region is better-prepared now than it was a few years ago for this predictable chaos.
======UPDATE April 28=====
Thomas O’Donnell writes in with the following, which is so substantive that I am just going to put it here in the post as I don’t want it to be missed.
Colombia announced they are shutting off the gas pipeline to Venezuela, citing expected upcoming El Niño shortages of water for hydroelectric production; so, they have to save their gas (the contract allows this in the face of ‘acts of God’). Meanwhile, the contract is ending (June?) and the pipeline is scheduled to be reversed in Sept. after a new contract is negotiated. Of course, this won’t happen as Venezuela has no gas to send to Colombia However, although people say the cutoff is because Venezuela might not be paying for the gas (which is of course likely), meanwhile, I am told by people who know the gas sector and Zulia well that in fact the El Niño explanation Colombia gives is a very real issue.
So, on top of all the other deep troubles in the west of Venezuela (Zulia and Tachira) face, presages serious shortages of gas for cooking and for electrical generation there. So, as you say, many effects of the swings in weather cycles… but esp. on top of a totally dysfunctional Venezuelan state that’s certainly not prepared whatsoever. Recall all the preoccupation with exactly how many meters and centimeters behind the damn at Guri a few years back? Here we go again!
Guri, as it happens, is in much better shape than it was in the 2010 El Niño, which followed showed up while Venezuela was still in a drought that started with the 2007 El Niño. But this is a great illustration of the kind of disruption that happens even with the kind of climate variability that is well within the historic norm.
Now think about how this bodes for climate changes that exceed historic norms.
Setty's notebook 
This overview is helpful. By the way: Colombia announced they are shutting off the gas pipeline to Venezuela, citing expected upcoming El Niño shortages of water for hydroelectric production; so, they have to save their gas (the contract allows this in the face of ‘acts of God’). Meanwhile, the contract is ending (June?) and the pipeline is scheduled to be reversed in Sept. after a new contract is negotiated. Of course, this won’t happen as Venezuela has no gas to send to Colombia However, although people say the cutoff is because Venezuela might not be paying for the gas (which is of course likely), meanwhile, I am told by people who know the gas sector and Zulia well that in fact the El Niño explanation Colombia gives is a very real issue.
So, on top of all the other deep troubles in the west of Venezuela (Zulia and Tachira) face, presages serious shortages of gas for cooking and for electrical generation there. So, as you say, many effects of the swings in weather cycles… but esp. on top of a totally dysfunctional Venezuelan state that’s certainly not prepared whatsoever. Recall all the preoccupation with exactly how many meters and centimeters behind the damn at Guri a few years back? Here we go again!
This action might be a retaliation for Colombia’s action n its gas…
BOGOTA
Petroleumworldcom, April 29 2014
A Colombian rebel group stopped and set fire to 12 vehicles transporting contractors and equipment to repair a pipeline on behalf of state-owned oil company Ecopetrol, police officials said on Monday.
No one was killed or injured in Sunday’s attack by the National Liberation Army, or ELN, in a rural area in Norte de Santander province, near the border with Venezuela . The area is a hotbed for rebel activity.
The convoy was intercepted and torched as it headed to carry out repairs on the Cano Limon-Covenas pipeline that has been halted for the last month after several bomb attacks by the ELN and the FARC, another rebel group.
Flow along the 780-km pipeline, with capacity to transport 210,000 barrels of crude from oil fields in northern Arauca province, has also been halted by a local indigenous community, which has refused to allow workers onto its land to do repairs.
The series of attacks and repair delays have obliged U.S.-based Occidental to stop work in the Cano Limon and Caricare fields, which usually produce 67,000 barrels per day, and prompted a declaration of force majeure by Ecopetrol.
Each day that production is stalled results in a loss of 7 percent of the Andean nation’s total production, which is around one million barrels per day, Ecopetrol said.
The ELN is the smaller of two rebel groups operating in Colombia, with fewer than 2,000 fighters. The larger rebel group, the FARC, or Revolutionary Armed Forces of Colombia, is in the midst of peace talks with the government.
There were 259 attacks on pipelines in 2013, the highest number in a decade and a 72 percent increase from the previous year.
So I gather Pacific Rubiales Energy did not cause the drought in Colombia?
If the causes were natural, it suggests that Colombia should better risk manage for weather volatility. That might could eliminating subsidies for agricultural activities vulnerable to cyclical drought.
The Casanare drought is probably not related to PRE.to. What’s more interesting is whether the drought-PRE link was believed by the locals. This article does a good job showing how public opinion, once poisoned, is very hard to recover. And how drought claims are one place where public opinion plays out. http://www.theglobeandmail.com/report-on-business/rob-magazine/high-and-dry/article18134225/?page=all
“The Casanare drought is probably not related to PRE.” Are you making a very bad joke? There is absolutely zero SCIENTIFIC evidence that the drought is any way shape or form related to Pacific Rubiales Energy.
In fact, I cannot think of even anecdotal evidence that points to oil exploration companies ever ‘causing’ a drought. But there is plenty of evidence that deforestation and overgrazing cause drought.
Supporting righteous farmers and herders in their mindless pursuit of the destruction of the earth is ‘popular’ with both left-wing and right-wing populists in many countries around the world. Here in Canada, you know well that both left and right parties support using public money to collapse fish stocks and sustain local economic stagnation.
Less well known is how righteous left-wing and right-wing Canadian politicians use equity arguments and generous dollops of public money to strip aboriginals of their resources.
As for Stephanie Nolen, she did great work in southern Africa and has already published some great stuff since being posted to South America. (You do know that we all share the same home town, eh?)
As for popular perception, there are always vested interests on both the left and right willing to exploit the ignorance and stupidity of common folks. Frankly, lack of education is a ‘resource’ for some. It can be easily manipulated for private gain.