Written by Matteo Pitteri

In my opinion, one of the facets of climate change that is least advertised about is the potential impact of increasing temperatures on our global weather patterns, understandably as it is still a contested topic within the scientific community. What is underregarded when considering the effects of climate change is the massive impacts the changes in these global weather patterns could have. One of the aims of this blog post is to highlight that there is still much we don’t know about the climate and the relations between its different features/aspects Many aspects of our climate are interconnected in ways we don’t yet realize or fully understand (SRM *cough cough*) and it would be wiser to take a step back and try to understand the picture from a different perspective before making a rash decision (*cough*).

For instance, a study conducted by the National Oceanic and Atmospheric Administration (NOAA) revealed that reducing particulate matter pollution in Europe and North America led to an increased number of tropical cyclones in the North Atlantic basin and the opposite occurrence in the Southern Hemisphere. Moreover, growth of particulate pollution in Asia led to fewer tropical cyclones in the western North Pacific basin. Please look here if you would like to learn more.

Occurrences such as these need to be carefully examined before decision-making processes are initiated. Moreover, there are instances where the gravity of climate change is underestimated due to the lack of consideration of the ripple effects caused by climate change. For example, it is projected that assuming a warming scenario of “business as usual” (RCP 8.5 from the IPCC’s 5th Assessment report), the ice loss from the Arctic and Antarctic would lead to an increase in temperature of 1.5 °C in the upper tropics on its own. This is due to the ice sheets having a global cooling effect, due to phenomena such as ice reflectivity of solar radiation (albedo) which would now be reduced. This would account for 20% of the expected changes in tropical warming. (England et al, 2020)

Global warming effects on ENSO

One of the weather patterns or phenomena that climate change would affect to cause the greatest repercussions is the El Nino Southern Oscillation (ENSO). This refers to two regular weather patterns occurring in the tropical Pacific Ocean, El Nino and La Nina. Normal conditions, when neither of these are happening, are when the wind blows (and thus warm water moves) from East to West, during El Nino these winds slow down or stop and during La Nina these winds get stronger.

Credits for picture: Welt Hunger Hilfe (WHH)

El Nino causes sea surface temperatures to rise and become homogeneous across the Pacific Ocean. El Nino’s effects are mostly felt in Australia and Southeast Asia as well as South America, but it has global implications. Australia and Southeast Asia tend to have warmer and drier conditions due to El Nino, increasing the risks of droughts, wildfires and heatwaves. However, in western South America, heavy rainfall occurs, increasing the risk of floods. On the other hand, La Nina typically has a cooling impact and has the opposite effect; increased rainfall in Australia and droughts in South America.

Interestingly, these two weather phenomena occurred recently, El Nino in 2023 and La Niña in 2022. It is currently unknown how climate change is affecting the ENSO but the La Nina phenomenon, which normally has a cooling effect, that occurred in 2022 was actually the 5th warmest year recorded. This hints at global warming’s significant impact on this weather pattern. However, it is known that as temperatures increase, warmer air can take up more moisture, approximately holding 7% more water vapor for every 1 °C increase, leading to more local rainfalls. Thus increasing temperatures caused by climate change could increase the the flood risks in South America caused by El Nino and in Australia by La Nina (Niranjan) (Grantham Institute). There are also certain impacts that have already been seen to be amplified: coral bleaching and increasing tropical Pacific storm activity. Moreover, the extreme rainfall patterns are expected to shift further from the Pacific (Kiest).

Lastly, another massive impact that global warming will have on weather patterns is how it will affect thermohaline circulation in the oceans worldwide. The Gulf Stream, a small part of this global conveyor belt of currents is a prime example of how this could occur. In this case, due to the Arctic and Antarctic ice sheets melting, a humongous amount of cold fresh water will mix into the oceans causing the Gulf Stream to possibly slow down or even stop (Turner). This would cause the increased vulnerability of ecosystems which will not be able to adapt to an environment that is changing ever so quickly.

I hope that through this small discussion, I was able to highlight that research should be conducted, especially in this crucial period and the decades, coming to attempt to predict and understand how our climate will be affected in the near future. At least to give some time to adapt…

References

England, M. R., Polvani, L. M., Sun, L., & Deser, C. (2020). Tropical climate responses to projected Arctic and Antarctic sea-ice loss. Nature Geoscience, 13(4), 275–281. https://doi.org/10.1038/s41561-020-0546-9

NOAA. “Weather Systems & Patterns | National Oceanic and Atmospheric Administration.” Www.noaa.gov, 1 Feb. 2011, www.noaa.gov/education/resource-collections/weather-atmosphere/weather-systems-patterns.

Niranjan, Ajit . “How Does Climate Change Affect El Nino and La Nina Cycles? – DW – 01/27/2023.” Dw.com, 2023, www.dw.com/en/how-does-climate-change-affect-el-nino-and-la-nina-cycles/a-64534667.

Grantham Institute. “What Is El Niño and How Is It Influenced by Climate Change?” Imperial College London, www.imperial.ac.uk/grantham/publications/climate-change-faqs/what-is-el-nino/.

Kiest, Kristina. “How Will Climate Change Change El Niño and La Niña?” NOAA Research, 10 Nov. 2020, research.noaa.gov/2020/11/09/new-research-volume-explores-future-of-enso-under-influence-of-climate-change/.

Kiest, Kristina. “Study: Reducing Human-Caused Air Pollution in North America & Europe Brings Surprise Result: More Hurricanes.” NOAA Research, 12 May 2022, research.noaa.gov/2022/05/11/study-reducing-human-caused-air-pollution-in-north-america-and-europe-brings-surprising-result-more-hurricanes/.

Turner, Ben. “Gulf Stream Weakening Now 99% Certain, and Ramifications Will Be Global.” Livescience.com, 16 Oct. 2023, www.livescience.com/planet-earth/gulf-stream-weakening-now-99-certain-and-ramifications-will-be-global#:~:text=As%20Earth. Accessed 4 June 2024.

Welt Hunger Hilfe. “El Niño – the Origin & Impact of the Climate Pattern.” Welthungerhilfe.de – Für Eine Welt Ohne Hunger Und Armut, www.welthungerhilfe.org/our-work/focus-areas/climate-change/el-nino.

Written by Matteo Pitteri

Climate change has impacted all parts of the world, leading to political conflicts, extinction of species, natural hazards, and more. While the effects of climate change on human life are often easy to observe, its impact on nature and the balance of ecosystems can be profound and complex. Nature is resilient, but many signs indicate climate change has significantly altered ecological dynamics.

In our latest podcast episode, I interviewed an ecologist to explore the question: How has climate change changed ecology? We discuss his personal experiences with climate change, the global and local consequences, and his views on the best solutions moving forward.

Unfortunately, due to changes with this platform, the podcast cannot be shared here directly. To learn more about “How Climate Changed… Ecology,” please visit the discussion page of the ECS on Canvas and listen to the podcast.