El Niño & La Niña - what are they and what effects do they have?

Hello everyone,

You've probably heard of El Niño and La Niña before. Especially El Niño has been discussed a lot recently in the media. El Niño and La Niña are part of a climate pattern found in the Pacific Ocean that occurs roughly every two to seven years. However there is no real regularity or predictability further into the future. They affect global weather patterns and economies.

So first of all, let's cover what is actually happening here. In normal circumstances trade winds blow across the Pacific from South America to Asia. This pushes warm water from South America to Asia meaning that the ocean is a lot cooler off the west coast of the Americas compared to the east coast of Asia. The cold water off the coast of the Americas comes from the ocean's depths and is filled with nutrients. During El Niño those driving trade winds become weaker or even stop entirely. Scientists haven't worked out what triggers this change. With no trade winds pushing the warm water towards Asia, the west coast of the Americas becomes warmer. El Niño was first recorded in the 1600s by local fishermen. It often peaks in December and lasts around nine to twelve months. El Niño also leads to a change in air pressure, with the atmospheric pressure over the easter tropical Pacific decreasing. This phenomenon is called Southern Oscillation. As it occurs simutaneously with El Niño the term "El Niño-Southern-Oscillation" (short: "ENSO") was coined.

But what are the effects of El Niño? As already mentioned the waters off the west coast of the Americas become warmer. This causes a change in weather across the Americas. Northern USA and Canada become warmer and dryer. The southern parts of the US experience heavy rainfall and increased flooding. El Niño causes a lot of erosion and flooding in coastal areas. It disrupts global air circulation and affects the monsoon season in Asia. The wetter, warmer conditions become perfect conditions for diseases such as malaria and cholera to spread. The areas that experience droughts also have a higher risk of severe wildfires. Because the nutrient-rich cold water no longer comes up to the surface along the coast of South America, this coast has a lot less nutrients. This leads to less plankton, which stresses the entire food web. Most fish species migrate or die. Local economies depending on fishing such as Peru suffer greatly.

On the other hand, there is La Niña. It's the complete opposite of El Niño and is caused by the trade winds becoming stronger than normal. This makes Asian coasts even warmer and American coasts even colder. The American coast has more nutrients because of more water swelling up from the depths. La Niña is responsible for droughts across southern USA, floods in Canada and northern USA and a more intense hurricane season across North America. Not only the Americas are affected, there is often flooding in Australia, Africa and northern Brazil. The monsoon season is once again affected.

A common question is how this affects or is affected by climate change. First of all, it's important to remember that this climate pattern has been around long before humans and is therefore not caused by man made climate change. It is visible in coral reef records going back for thousands of years. However it is worth noting that El Niño has been stronger in recent decades. It is unclear whether this is because of climate change. What is clear is that climate change plus the effects of El Niño is a disastrous combination. While the future is unpredicable, there are two probable possibilities. One is that climate change will cause extremely strong El Niños and La Niños, causing massive destruction. The other possibilty is that climate change will completely change the weather patterns globally and El Niño and La Niña might not exist further into the future.

We hope you enjoyed this post. Merry Christmas and Happy Holidays!

Your Green World Blog Team💚

Sources:
https://oceanservice.noaa.gov/facts/ninonina.html
https://education.nationalgeographic.org/resource/el-nino/
https://education.nationalgeographic.org/resource/la-nina/
https://www.dw.com/en/how-does-climate-change-affect-el-nino-and-la-nina-cycles/a-64534667

Images:
This image, owned by Rawpixel Ltd (on flickr.com), is licensed under CC BY 2.0.

Comments

Deforestation and why it’s a problem

Hi everyone, Welcome back to another post. Today we’ll be talking about deforestation and its impacts on our earth. Deforestation, the widespread clearance of natural forests, has been happening for thousands of years. One example is Western Europe, where, two millennia ago, 80% of the land was cloaked in dense forest cover. However, over time, a significant portion of this green expanse was sacrificed to create room for crops, livestock grazing, and as a source of fuel and building materials. Presently, a mere 34% of Western Europe retains its woodland. Today, the tropics deal with the brunt of deforestation. Activities such as mining, agriculture, road construction, and the establishment of vast cattle ranches drive the mass clearance of tropical rainforests. This results in the release of huge amounts of carbon dioxide into the atmosphere, exacerbating the global climate crisis. The consequences come in two waves: first, the reduced number of...

Climate change: what is it and what's the problem

Hello, I've noticed that we are always mentioning climate change. Not only us blog editors but also politicians, activists and so on. The words climate change are bounced around in the media and probably in your households, but do you actually know what it is or how it works? I know that for a long time, I didn't know what it really meant. I hope that this post changes that. What is climate change and how does it work? The words climate change describe a slow shift in the earth's temperature and changes in the weather patterns. Having a single warm winter does not instantly mean climate change. Climate change happens over a long period of time. If you look at a temperature graph over the years, it doesn't go up in one day and then stay the same for another hundred years. It curves up slowly but steadily. This is a average temperature graph from 1880 to just after 2000. You can see how the temperature gradually gets warmer....

The Responsible Traveller by Karen Edwards || a practical guide to reducing your environmental and social impact // BOOK REVIEW

HI Everyone! Our January monthly post was a zero-waste challenge, but as we explained in our 2023 wrap up , this year we will be alternating a monthly challenge with a book review, of course related to the environment. This week, I'm going to share a recommendation for a fantastic book, all about how you can travel more sustainably and responsibly. I absolutely love travelling, but I'm also very aware of the impact it has on the world, and I am very keen to learn more about how I can further reduce my impact. That's why I bought this book around a year ago, and I've really enjoyed reading it and learning from it. This is a practical, small-format guide, sharing both basic information about the climate crisis and the impact of various travel activities, and how you can do your bit. It shares specific journeys that are more environmentally friendly options, for example long distance train journeys such as The Alaskan Railroad with its stunning alpine forests and wide ar...

April Top Tips: ten tips for environmentally friendly travel

Hi Everyone! We haven't been very present on the blog again recently but we are back today with ten top tips for environmentally friendly travel. Most forms of travel over long distances (unless you are willing to put in a lot of physical effort) use fossil fuels and are generally not good for our planet. So today we will be giving you a few tips which although won't mean that your travel is 100% planet friendly, will be a good start to doing as much as you can. Your Green World Blog Team💚 1. Use trains and boats rather than planes where possible Planes are awful for the environment. They are, however, extremely practical and so easy to use, cheap...It's hard to avoid them! They are so quick too so you don't have to spend as much time travelling. However, they are really bad for the environment. For example, you could fly once to Edinburgh from Heathrow for the same carbon dioxide levels as driving to Edinburgh 336 times! 2. Fly...

10 Animals on the edge of extinction, You did not know about no.1 - Yangtze Finless Porpoise

The first animal of this series is the Yangtze finless porpoise, a dolphin living in fresh water in southern China in the Yangtze river. It is one of the very few dolphins living in fresh water and the only species left in the Yangtze river. Unfortunately, the porpoise is facing extinction. What is it? The Yangtze finless porpoise is a dolphin species living in the Yangtze River in southern China. It is one of the very few dolphin species that live in freshwater, and the only one that survived in the Yangtze river after the Baiji Dolphin was declared functionally extinct in 2006. It characteristically is about 2 meters long, has no fins -as the name suggests- and no beak. Its mouth however is curved upwards like a smile, giving the Porpoise and cute and friendly face. It feeds on small fish, crustaceans and molluscs. Sadly, the Yangtze finless Porpoise is considered "critically endangered" as there are only about 1000 of them left. Why i...

Linking climate change and inequality - 'The Great Carbon Divide'

Hey everyone, Have you heard of 'The great carbon divide‘? It is often referred to as the 'carbon footprint gap' or the 'emissions imbalance‘, and produces frightening numbers. The great carbon divide describes the huge gap between the amount of carbon dioxide the rich versus the poor emit, and these numbers shocked even us. What does this mean? There have been many different studies, and all of them show terrifying results. One study from the Guardian and Oxfam, reports that the richest 1% of the world's population emit more carbon than the poorest 66%. The richest 1% consist of 77 million people, which may seem like a lot at first, but the poorest 66% refers to over 5 billion people! Africa, which is home to 17% of the world's population, only causes 4% of the world's emissions. This top 1% emitted 16% of global CO2 emissions in 2019, that's 5.9 billion tonnes of CO2. Modelling suggests that it would take someone who isn't in the top 1% about 150...

Evolution

Hi, So today, I am going to talk about evolution. We have mentioned this before in our Galapagos Ecosystem series but we’ve never gone over exactly what it is. So before Charles Darwin thought of his theory of evolution, the majority of people in Europe thought that all species were unrelated and that humans were not related to animals. This was mostly based on Christianity. Darwin studied hundreds of different species and on the Galápagos Islands , he first started to form his theory of evolution. Darwin's theory of evolution by natural selection, as it was later called, is best explained by the example of the giraffe. Let's assume that giraffes have short necks (as they did many centuries ago). Now a mother has two children. By chance, one has a slightly longer neck. This is a coincidence. As the giraffes feed on the lower leaves of the trees, these slower disappear. There aren't enough leaves for the giraffes. Thus the giraffe wi...

Animals 11-15 in our '50 incredible animals' series

Hello, We have another five amazing animals for you today. Enjoy! 11. Dhole This is a dog species which looks rather like a red fox . They are difficult to put into any of the dog subfamilies. They aren't foxes, nor wolves, nor domestic dogs. Dholes are fast runners and live in packs of 5-12 individuals. Although sometimes, different packs will join forces to become a pack of 30 or more individuals! However, these super packs are broken up after a successful hunt. The different packs rarely attack each other as neighbouring packs are often closely related. Dhole packs live in burrows with multiple entrances. They can be found in eastern and southern Asia. They eat wild berries, insects and lizards and as a pack hunt deer, rodents and other wild mammals. Interestingly, unlike other dogs, they rarely kill by biting at the throat. They are also good swimmers! 12. Irrawaddy dolphin The Irrawaddy dolphin can be found in coastal areas of south a...

Metamorphosis

Hello! Today we thought it would be good to explain exactly how metamorphosis works. It's a term that we often use when talking about frogs, butterflies or other animals, but we've never actually explained what it is or how it works. What is metamorphosis? Metamorphosis is the term used to describe the changes that some animals undergo when turning into adults. It is a physical change that happens after birth/hatching. There is a brilliant quote from the website a-z animals that I just couldn't put any better: unlike the typical subtle developments in animals, metamorphosis is dramatic. It’s controlled by a release of hormones in the cells. Mammals usually move from adolescence to adulthood and old age gradually, maintaining their form and shape. However, in metamorphosis, an animal moves through those stages and changes from one form or shape to another. How does metamorphosis work? Let's take the classic butterfly example./d...

The life of ... Atlantic salmon

Hello everyone, Today we're talking about Atlantic salmon. Atlantic salmon are found in the north Atlantic and the rivers that flow into it. They can grow up to a meter long and are classified as Least Concern by the IUCN . Atlantic salmon start their lives in rivers. The pea-sized eggs are laid in autumn and hatch in April or May. The tiny salmon are called alevins. They feed on aquatic invertabrates and eventually devolop into parr. Parr are easily recognised by destinictive patterns and markings on their flanks. After up to several years, the parr develop a silvery sheen. These replace those characteristic parr markings. Their bodies change in preparation for the salt water and they are now called smolts. They swim downstream with the current all the way to the ocean. In the deep sea waters, the smolts feed on crustaceans and small fish for 15-50 months. However they are hunted by a number of predators including, sharks, seals and of ...

Green World

Search This Blog