A global sea surface temperature anomaly plot showing cooler than average sea surface temperatures in the eastern Equatorial Pacific, indicating the beginning of the cool phase of the ENSO climate oscillation, also called "La Niña".
In the US we often hear the meteorological term “El Niño” when a broadcast meteorologist is talking about unsettled weather like thunderstorms, squall lines, and tornadoes. It’s true, in the southwestern US, El Niño years tend to be wetter and stormier than they are during other phases of the larger climate oscillation called the “El Niño-Southern Oscillation” (ENSO) phenomenon.
We are just wrapping up an El Niño event and transitioning to La Niña conditions.
The El Niño-Southern Oscillation refers to a paired atmospheric and ocean current which sets up in the eastern equatorial Pacific Ocean. It’s called an oscillation because the conditions go one way, then back to the middle, and then the other way, in a cyclical way. In the warm phase, which we call El Niño, the ocean water in the Eastern Equatorial Pacific (EastPac) is warmer than normal. In the cool phase, the ocean water in the EastPac is cooler than normal. In neutral conditions, the water is close to average temperature.
The Southern Oscillation part of ENSO refers to an atmospheric pressure pattern that goes along with the change in water temperature. Warmer water in the EastPac means lower pressure in the atmosphere over that region. Changes in atmospheric pressure determine the strength of the winds that blow across the central Pacific Ocean basin. The change in water temperature tends to strengthen the pressure gradient, which reinforces the temperature differences that characterize whichever phase is active.
The reason the phenomenon is called El Niño is because it was originally observed by Peruvian fisherman as the fish catch dwindled around Christmastime during warm phase years. They named it El Niño after the Christ child, whose arrival is observed around the same time of year.
Scientists monitor ENSO so that they can know when the phase might be shifting from the warm phase, which is El Niño, to the cool phase, called La Niña, or when it might be transitioning into a neutral phase, which some people jokingly call “La Nada.”
Meteorologists are interested in monitoring ENSO because it has a big impact on our weather. In the southwestern US, including Texas, El Niño brings wetter, stormier conditions. El Niño can promote a more active severe weather season in the Great Plains of the United States. La Niña means we will have drier weather in Texas and is often associated with drought.
El Niño is also a driver of global temperature. That area of warm water in the EastPac transfers lots of heat energy from the ocean into the atmosphere. That means that El Niño years tend to have higher global temperatures. Paired with the increase in global temperature caused by the accumulation of greenhouse gases in the atmosphere, last year’s El Niño caused the highest global temperatures ever observed.
Because of its influence on the flow of air in the upper atmosphere, ENSO impacts weather around the world. While Texas sees an increase in storms and tornadoes, other parts of the world, like southern Africa, experience enhanced drought. And that has a devastating impact on the people who live there.
A recent article from Yale Climate Connections talked about how El Niño is worsening drought in southern Africa. The article details the devastating impacts of severe drought in the region, with farmers reporting failed crops, leading to widespread hunger.
The article reports on recent science, which has found that climate change has likely made ENSO conditions stronger over time. They interviewed NOAA scientist Michael McPhaden who commented on the study, saying that “while this link is “likely” rather than certain, there is “very strong evidence” that even if ENSO events themselves stay the same, global warming can still amplify their impacts, as has happened this year around the world.”
Through the EcoFaith Dialogues series of webinars, United Methodist Global Mission Fellows serving in Africa have told us firsthand about the ways parts of Africa have been devastated by severe drought. Shamiso Winet Mupara and Josiah Momudu both talked about the devastating affect of drought across agrarian economies where drought has killed crops and livestock. There was no part of village life untouched by the devastating drought.
The conditions in different regions of Africa are an example of how the effect of climate change on large-scale climate cycles can be complex.
UM Global Mission Fellow Tanaka Ndongera recently shared with me a story about flooding in Kenya this April that was caused by another large climate oscillation, the Indian Ocean Dipole (IOD). During the positive phase of the IOD, the Indian Ocean is unusually warm, which promotes evaporation. The high evaporation rate contributes to higher humidity in the atmosphere, which leads to extreme precipitation.
Ndongera wrote:
“During a positive phase the waters in the western Indian Ocean are much warmer than normal and this can bring heavier rain regardless of El Niño. However, when both a positive IOD and an El Niño occur at the same time then the rains in East Africa can become extreme. The impact has been massive as the capital city of Nairobi and surrounding areas were particularly affected. The Nairobi River and the Athi River both burst their banks displacing 40,000 people. At least 228 deaths, 164 injuries, 72 missing and 131,450 displaced people were reported. The UN Office for the Coordination of Humanitarian Aid also reported at least 960 livestock and 24 thousand acres of farmland were flooded.”
Ndongera shared a photo of a local pastor in the middle of the flooded city of Nairobi where he attended worship at Githurai-Kimbo United Methodist Church. The pastor is in full vestments leading worship in high rubber boots to keep out the twelve inches of water that flood the street and the buildings on either side.
Whether it is drought or flood, our global missionaries tell us a consistent story of the way climate impacts devastate entire economies in the global south.
As it says in the Yale article, our global missionaries and local advocates have done tremendous work to develop drought-resistant forms of agriculture. But even those techniques cannot keep up with the intensity of the changes that are occurring.
And this is why the global community must rally around our developing countries as we develop our plans to combat climate change. A well-run climate finance fund that offers support to developing countries as they adapt to the impacts of climate change is not just the right thing to do from a justice perspective, but additionally all of us benefit when every country is empowered to mitigate climate change within their borders.
On a recent webinar on climate finance (recording available here), experts called for renewed and robust commitment to climate finance, a rapid increase in climate mitigation ambition, and increased support for adaptation measures in the countries experiencing the most severe impacts of climate change.
Representatives from small island nations noted during the webinar that their economies have lost $500 billion dollars to bad weather caused by climate change, that reinsurance costs have gone up by 60%, and that they are simply out of options. Commitments to Loss and Damage funding and other climate finance mechanisms must exceed the current goal of $100 Billion in order to adequately address the current moment.
Climate extremes like the droughts and floods we see in southern and eastern Africa are reminders of the threats to global stability posed by unchecked climate change. Droughts, famines, and floods are all drivers of global migration. The justice issues of climate impacts are compounded many times over when you add in the dynamics of migration, both internally and across international borders. For people of faith, supporting generous and robust climate finance is a straightforward, effective way to address a host of justice issues facing our neighbors in the global south.