Dr George Adamson is a Lecturer in Geography at Kings College London. His research and academic interests focus on environmental history, climate change adaptation and policy. He looks closely at both the human and physical side of climate issues, such as how extreme weather events, like droughts and floods, affect people directly as well as indirectly in wider communities. We talked to him about the impact the El Niño phenomenon can have on societies.
What impact can El Niño have on societies and communities?
The principle impact of an El Niño event is in the coastal communities of Peru and Ecuador. These are exceptionally dry regions, some of which receive only a few centimetres of rainfall in normal years. In El Niño years this can increase by more than a factor of ten. This brings devastating floods, destroying buildings with the intensity of the rainfall and damaging infrastructure in very severe ways. Often this includes the destruction of bridges or of large portions of major roads. As El Niño is an oceanic phenomenon as well as atmospheric, El Niño can also have profound implications on fishing. Warm water during El Niño years can cause fish to migrate away from the coast, causing severe problems for fishing communities, as well as for marine birds and mammals. But El Niño has global effects: Australia and Indonesia have droughts during El Niño years that can lead to wildfires. El Niño can also cause severe droughts in India, in parts of Africa and in Brazil, as well as floods in California.
In ‘El Niño years’, warm dry air descends in the western Pacific creating droughts and South America receives warmer waters off its west coast.
Do communities’ responses to El Niño vary with their geographical location?
Very much so, as the effects of El Niño are so different around the world. These differences can take place over relatively small geographical distances. For example, whilst coastal Peru receives floods, the Peruvian uplands (in the Andes) tend to have reduced rainfall during El Niño years. Likewise peninsular India often suffers droughts during El Niño, whereas southern India and Sri Lanka tend to have increased monsoon rainfall. No El Niño event is the same. For example, the 1997 El Niño (which was very intense) had no impact upon the Indian monsoon. Whereas that of 2002 resulted in a significantly diminished monsoon but few impacts in Peru. This makes El Niño very difficult to categorise.
How have responses to the negative effects of El Niño changed over time?
In general the negative effects of El Niño have reduced through the twentieth century as societies’ abilities to deal with climate extremes have increased. This is true of all extremes (such as cyclones, droughts and snowstorms), not just El Niño. The days of famines in India that kill more than ten million people, such as in 1877, are fortunately behind us. Mostly this is because we have a much better understanding of what El Niño is now, and are therefore able to predict it with a reasonable degree of accuracy. However, population growth makes the situation more complicated. El Niño itself also continues to throw up surprises, making one hundred percent accuracy in prediction difficult, and prediction of the exact impacts of El Niño even more so. Climate change makes things even more complex.
If one were to compare El Niño events over time, how can one ensure the reliability of one’s data? One might assume historical data is somewhat anecdotal.
It is! Exact comparison between events is very difficult before about 1900. Detailed information on famine deaths in India, for example, was only collected from the late eighteenth century, and then only in certain regions. It is also difficult to know exactly whether past climate extremes were related to El Niño. Australia has always experienced droughts, but we have only known about El Niño in any real detail for the past fifty years or so. Of course we can make educated assumptions about which previous droughts were connected to El Niño, but the further back in time we go the more uncertainty there is. The important issue is to learn from the successes and mistakes of the past in the way people responded to climate extremes. Ascertaining individual events to El Niño is important, but possibly secondary.
How might the nature of El Niño transform as climate change takes hold?
This is a difficult question. The problem is that El Niño is a system not an individual event. El Niño is one extreme, the other (‘extreme-normal’) is called La Niña, and there is a continuum in between the two (the whole system being called the El Niño Southern Oscillation, or ENSO). Moreover the system is responsive to atmospheric changes and to sea temperature. This makes modelling the influence of climate change on El Niño quite difficult. Models currently show different projections, some showing a move towards more frequent El Niño events and some towards more frequent La Niña. There is some evidence that the whole system may be becoming stronger (i.e. both El Niño and La Niña are becoming more regular and greater in intensity), suggesting a move towards a climate of extremes. A lot of research is being devoted towards this area, but it is currently inconclusive.
In poorer nations affected by El Niño how much responsibility falls on national governance to provide management solutions?
This is a difficult question and one to which I would not want to attempt an answer. It depends on your faith in the respective ability of the markets, of governments or of non-government organisations to address disaster response. If I was to venture a tentative opinion I would say that national government has an important role to play, but let us not forget that the growth of the insurance industry has played a big role in the reduction in vulnerability to natural disasters (climatic or otherwise) in the developed world. It is also important to remember that we can never mitigate against El Niño as it is a natural event. Even if we reduce anthropogenic climate change to zero El Niño events will continue to occur. So the simple answer is to adapt, although mitigating against climate change itself by reducing our carbon dioxide emissions is of course important, and not just for El Niño.
Should we be worried about El Niño events in the UK, even though they do not occur here?
Global markets are interconnected so any major event in the world will affect the UK to some degree. But it is not entirely true to say that El Niño does not affect the UK. El Niño increases the likelihood of cold winters in western Europe, and was implicated in the recent very cold winter of 2010. This does not mean that El Niño is ever something we should worry about, but we should at least be prepared for its effects. ENSO can also have positive effects for the UK. La Niña conditions bring damp weather over Australia, more similar to summer conditions in England. It has been suggested that this may have contributed to the England cricket team’s win in the Ashes down under in 2011. So it is not all bad.
Key Words
Adaptation
The action of accepting that natural hazards or natural phenomena are going to happen and adapting one's life and home to cope with those changes rather than prevent them.
Climate Change
A substantial change in the long term weather patterns of a particular place.
Drought
A period of time over which an area of land experiences a much reduced water supply.
El Niño Southern Oscillation
The movement between one form of localised climate conditions to another across the Pacific, normally creating extreme weather conditions for those living in coastal regions, as well as elsewhere.
Famine
A period of time over which an area of land experiences a much reduced food supply.
Infrastructure
The services and facilities needed for an economy to function, for example transport networks, energy supply and health care.
Mitigation
Actions that attempt to reduce the severity of a hazard by targeting its key processes.
Monsoon
The season experienced typically in south east Asia where heavy rain falls with predictable frequency.
Lesson Ideas
Students can annotate a world map showing areas that benefit and suffer as a result of El Niño. They can compare these locations with other areas that are already experiencing extreme weather that comes about as a result of other forces such as climate change.
Using historical data students can graph the occurrences of El Niño over the last one hundred years. From this they may be able to see a frequency pattern emerge and predict when the next El Niño or La Niña event will occur.
Students can design an advice leaflet to be given to people living in areas susceptible to the effects of El Niño. This can detail what to expect during an event and what residents can do to protect themselves both in the short terms and in ways that makes their lives more sustainable in those locations in the short term.
Links
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Article: Documentary reconstruction of monsoon rainfall variability over western India, 1871-1860
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Article: Long term variability in the date of monsoon onset over Western India
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Article: Recent Advances in the Historical Climatology of the Tropics and subtropics
George was interviewed in May 2015
