Earth’s Complex Climate Network

Imagine Earth as a giant, complex system, with air, water, land, and ice all “talking” to each other through a language we call climate. Like talking on a telephone to a friend across the world, Earth’s climate conversation stretches over thousands of kilometers, from the icy poles to the tropical regions near the equator. Not only do the parts of Earth’s climate system “talk” to each other, but they can affect each other in all kinds of complicated ways to produce the weather you experience wherever you live, like heatwaves, dry spells, or heavy rains. These long-distance climate effects are called teleconnections, and they are a natural part of Earth’s climate system.

In the remainder of this article, we will explain what causes teleconnections, how scientists understand and predict them, and how shifts in teleconnections caused by climate change can affect local weather patterns—maybe even in your part of the world!

Teleconnections Explained

Teleconnections are like invisible threads weaving across the Earth, connecting weather and climate events in one part of the world to things that happen thousands of kilometers away (remember that weather describes daily, short-term conditions of the atmosphere, while climate describes long-term patterns). There are several teleconnection pathways, and many of them are created by the constantly changing circulation of air in the atmosphere and water in the oceans. One of the most well-known examples of teleconnection is the El Niño-Southern Oscillation (ENSO), which involves natural, periodic changes in ocean water temperatures, air pressure, rainfall, and in the way water circulates in the Pacific Ocean. For example, when the Pacific Ocean warms up in the normally cool eastern tropics, it can cause floods in one part of the world and droughts in another (to learn more about ENSO, see this Frontiers for Young Minds article), The trade winds, which blow from the west to the east in tropical regions of the Earth, keep the warmest water near the Asian coast and bring up cold water from the depths near South America. Every now and then, the trade winds get weaker and, instead of Asian coastal waters, the waters in the middle of the Pacific get warmer. Warm waters make it easier for rain and thunderstorms to form, so these also move from the Asian coast further into the Pacific. Rain systems are all connected in the atmosphere, so regions that are normally wet get drier (such as Indonesia, which can experience wildfires), and other areas, such as California in the US, get more rain.

There are also teleconnections between Earth’s polar regions and the rest of the planet. For example, the jet streams are giant, invisible rivers of air high up in the sky that move from west to east. Jet streams are caused by two things: Earth’s rotation and the difference in temperature between the equator and the poles. Jet streams play a big role in Earth’s weather—they can affect how storms move and how warm or cold it gets in various places. Jet streams are like highways for weather systems, helping them travel across the globe.

Using Computers to Predict Climate Change

Figuring out climate complexities and how teleconnections work is the job of researchers called climate scientists. Climate scientists use powerful computers to create programs called climate models, which can help them understand climate teleconnections of the present climate and “project” (predict) the effects that climate change will have—both on teleconnections and on the resulting weather conditions in specific regions of the world. A climate model is basically a virtual version of the real world, in which scientists can do “experiments” to see how changes in one thing (like the amount of greenhouse gases that humans release) affect other things (like global temperatures or the amount of rainfall in a certain region). Many climate models exist, but they all represent the different components of climate, including sea ice changes, sea level rise, rainfall amounts (as described in this Frontiers for Young Minds article), or the number and strength of heatwaves, for example, and how they interact (Figure 1).

Teleconnections and Climate Change

You may have heard that 2023 was the world’s warmest year on record. But temperatures are not increasing in exactly the same way all over the world, and other effects of climate change vary by location, too (for more info, read this Frontiers for Young minds article). So, what might rising global temperatures mean for the weather and climate where you live? That is a very difficult question for climate scientists to answer, especially since, as Earth’s climate changes due to human activities, the behavior of teleconnections is changing, too!

For example, monsoons bring vital rain to many parts of the world, but the rain they bring has become more intense in some places in recent years due to climate change. Monsoons are heavy rainstorms that happen mostly in tropical areas during the “rainy season”. As greenhouse gases like carbon dioxide build up, they change the temperatures of the oceans and the atmosphere. When these temperatures are out of balance, natural teleconnections can be disrupted. For example, scientists have observed that changes in ENSO can make monsoons stronger [1] and can also lead to increases in other extreme weather conditions in some regions, such as more and stronger hurricanes and longer droughts.

Similarly, as sea ice melts in the Arctic, it might weaken and shift the jet stream southward. This could bring stormier conditions to the Mediterranean and drier, more settled conditions to Western Europe. Jet streams are naturally quite variable. They do not stay in the same place or move at the same speed all the time. So, scientists are still uncertain about exactly how much the melting ice at the poles might be shifting the jet stream and increasing its variability, leading to extreme weather events. There is still much work to be done to fully understand this and other teleconnections, and the role that climate change might be playing in changing them.

Computer Models are Not Perfect

Climate scientists are unsure what caused 2023’s record-breaking temperatures because, as you have seen, Earth’s climate is extremely complicated. This means that, to make the most accurate predictions, climate models must be complicated, too! There is not enough computing power in the world to create one model that includes every possible feature of the Earth’s climate accurately. Also, climate scientists use different methods to model different features, such as ocean currents, atmospheric conditions, ice caps melting, and the effects of human activities like deforestation and pollution. Even the best models are not perfect—they cannot capture every aspect of extremely complex climate processes with complete accuracy, so the predictions they provide are never 100% certain. This explains why different climate models do not always give the same results. For example, one model might say storms more frequently move northwards, while another might say they more often move southwards. One way to deal with this is for climate scientists to look at lots of models to figure out which models are the best for which questions. They can also combine information from multiple models to help make the best predictions of how climate change will affect specific areas (Figure 2).

Analyzing and combining information from climate models is extremely important, because knowledge is power! The more certain scientists can be about how climate change will affect specific locations, the more effectively local authorities will be able to protect those areas [2, 3]. For example, if scientists can project with very high certainty that sea level rise and increased rainfall will flood New York City over the next 50 years, steps can be taken in advance to protect people—like building flood walls or moving people out of areas most likely to flood. Accurate climate knowledge also helps scientists to measure the success of actions taken to fight climate change, like laws to reduce emissions of greenhouse gases.

Preparing for the Future

As Earth warms, we are seeing more—and more extreme—weather and climate events, from blistering heatwaves to torrential rains. We now know that, due to climate teleconnections, the specific causes for certain weather events might be thousands of kilometers away. Teleconnections show us that Earth’s climate system is deeply interconnected, with changes in one area rippling across the globe. Understanding teleconnections is an important part of predicting how climate change will affect communities in the future, and climate modeling is helping climate scientists to do just that. By studying information from many climate models, scientists can better forecast weather and climate trends, helping communities prepare for and fight climate change and extreme weather events. Hopefully, the more we learn about Earth’s fascinating and complex climate system, the easier it will be to learn to live within its limits and reduce the negative impact that humans are having on the environment.

Glossary

Climate: ↑ The average weather conditions in a region over a long period, including temperature, precipitation, and wind patterns.

Weather: ↑ The daily conditions of the atmosphere, like temperature and rain, which can change quickly. Weather differs from climate in that it describes short-term changes, while climate describes long-term patterns.

Teleconnections: ↑ “Tele” means “distant” or “far from”, so teleconnections are climate phenomena that link weather and climate events in different, sometimes very far apart, regions of the world.

El Niño-Southern Oscillation: ↑ A climate pattern involving changing ocean temperatures in the central and eastern Pacific that influence global weather and climate.

Climate Scientist: ↑ A scientist who uses climate models to understand Earth’s current climate and predict how the climate might change in the future.

Climate Model: ↑ A computer simulation used to understand various aspects of Earth’s climate system.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

Edited by Susan Debad Ph.D., graduate of UMass Chan Medical School Graduate School of Biomedical Sciences (USA) and scientific writer/editor at SJD Consulting, LLC. We would like to thank the coauthors of the original manuscript: Jonathan D. Beverley, Tom Bracegirdle, Jennifer Catto, Michelle McCrystall, Andrea Dittus, Nicolas Freychet, Jeremy Grist, Paul Holland, Caroline Holmes, Simon Josey, Manoj Joshi, Ed Hawkins, Eunice Lo, Natalie Lord, Dann Mitchell, Paul-Arthur Monerie, Matthew D. K. Priestley, Adam Scaife, James Screen, Natasha Senior, David Sexton, Emily Shuckburgh, Stefan Siegert, Charles Simpson, David B. Stephenson, Rowan Sutton, Laura Wilcox, and Tim Woollings. This paper is largely based on the results of two grants from the UK Natural Environment Research Council—Robust Spatial Projections of Real-World Climate Change, NE/N018486/1 and Emergence of Climate Hazards, NE/S004645/1.