Skip to main content

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💚




Comments

Popular posts from this blog

16.08.2020 Animal of the week: Elephant

Hello. On the 12th of August it was International Elephant Day, so we decided that this week's post should be about elephants. Elephants are the largest living land mammals. There are three types of elephant; the African bush elephant; the African forest elephant and the Asian elephant. African elephants have larger ears, whereas Asian elephants have smaller ears. Elephants use their trunks to breath, bring food and drink to their mouths and to grasp objects. Elephants' legs are like pillars. They carry the Elephant's massive weight. African bush elephants weigh 6000kg, Asian elephants weigh 4000kg and African forest elephants weigh 2700kg. Basically, they are very heavy.Elephants eat grasses, small plants, bushes, fruit, twigs, tree bark, and roots. Elephants can live up to 70 years old in the wild. They communicate by sight, touch and smell. Sadly, these wonderful mammals are in danger. African elephants are listed as vulne...

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...

Photo Essay || Iceland Series (part 1)

Hi Everyone! I recently went on a school trip to Iceland! It was such an incredible experience (and I'm going to sound cheesy now) but it was also incredible to do it with some of my closest friends! I saw so many incredible things and learnt so much, so I couldn't resist sharing a little Iceland mini series of posts, all about Iceland, both my experiences there and what I saw, but also the way it uses geothermal energy, and the animals, natural landforms and plants that are there. Today I'm sharing some photos of my trip. These are all photos I have taken, and are also the highlights so please bear that in mind as you browse these! I hope it is interesting and inspires you to book a trip to Iceland! The blue lagoon <33 landscapes.... Lost little farmhouses a...

Announcement: Factfile

This image is owned by a blog editor.

Animals 16-20 in our '50 incredible animals series'

Hello and welcome to another 50 incredible animals post where we are sharing 5 more animals that you (hopefully) haven't heard of or know much about! Enjoy! 16. Mantis shrimp Mantis shrimp are colourful but deadly sea-dwelling creatures that live in tropical and sub-tropical seas in the Indian and Pacific Oceans. They may look pretty however, they have a surprisingly strong punch. They can punch up 50 miles per hour with a force of over 1 500 newtons. That's enough to go destroy crab shells and punch their way straight through the glass of an aquarium. The punch is as fast as a bullet and is 2 500 times the force of the animal's on weight. If humans could do that, we would be able to punch through steel! Also mantis shrimp are thought to have the most complex eyes in the animal kingdom! All in all, mantis shrimp are pretty incredible animals! 17. Clownfish Clownfish are one example for the amazing corporations in the natur...

Animals 36-40 in our '50 incredible animals' series

Hi, As you probably noticed, we took a break from this series, mostly due to having just too much to do. But we're back now with the last three posts. 36. The Pinocchio frog The Pinocchio frog can be found in the Foja Mountains in Indonesia. They mainly eat insects, although little is known about them. They are named because the males have a spike on their noses. They were only discovered in 2008, and this was completely by accident! It remained unnamed scientifically until over ten years later when it was given the name " Litoria pinocchio " . There is very little information about them but Wikipedia states that "the male Pinocchio frog inflates its nose when calling, and the nose decreases in size when the frog is calm and quiet," which I think is hilarious and so interesting! 37. Snub-nosed monkey Especially noticeable due to their curious looks, the snub-nosed monkeys can be found in the forests of central China and northern...

The life of ... a cicada

Hi everyone, We're back to talk about another animal. Cicadas ( Cicadoidea ) are invertebrates and are 1.9cm to 5.7cm in size. There are 3 000 species that can be divided into annual cicadas and periodical cicadas. Annual cicadas can be seen annually and are found worldwide whereas periodical cicadas only leave the ground every decade or two and are only found in North America with hotspots in the eastern and central areas of the United States. Most annual cicadas have a lifespan of about two to five years and periodical cicadas can live up to the age of 17. Female cicadas lay around 400 eggs split up over several places. They normally lay their eggs on twigs, branches or other vegetation. The eggs hatch after about six to ten weeks, now known as nymphs, and dig their way into the soil. The nymphs feed on the liquids found in plant roots. They fully develop underground, before molting their shells and coming to the surface, now fully deve...

Turning waste into valuables

Hi, So this post was requested on Twitter after our September Top Tips about recycling . Today we will be talking about how to turn complete waste into something reasonably valuable. This is basically a form of upcycling but to a more extreme level. 1. Ecobricks So, almost a year ago we did a post about ecobricks , but they are such a good example of turning waste into valuables that we decided to put it here anyway. Ecobricks are a building material made from plastic. The waste plastic is washed and then compacted into a clean plastic bottle (also waste). The bottle becomes very hard and durable. Multiple bottles can then be used as bricks and cemented together. The 'bricks' are strong and do not decompose. For more info, read our post where we go into more detail. 2. Metals Although this may seem like something not worth the time. When you separate the metals in waste (for example an old car), you can get usable metal out ...

10 Animals on the Edge of Extinction No. 10- The Javan Rhino

The Javan rhino is listed as the 1st animal on WWF’s list of the 10 world’s most endangered animals, and I for my part, had never heard of it! If you hadn’t either, we’re changing that now.  A bit about the rhino’s lifestyle The Javan rhinos are now exclusively found on the island of Java in Indonesia, but were once found in vast regions of northeast india and Southeast Asia. They have a dark grey colour which looks almost black when wet, and their (often pink) skin folds look a bit like plated armor. Both males and females have lower incisors which resemble tusks that they use to fight. Males have one relatively short horn of about 25 cm (10 inches).  Javan Rhinos live in tropical forests, marshy areas and in the thick bush. They are mainly browsers and eat over 100 plants species they find in the forest, weigh between 900 and 2300 kg (1984-5071 pounds) and are between 3 and 3.2 meters (10- 10.5 feet) long.  How endangered are we talking?  Javan rhinos are the most ...

Why Don't People Switch To Electric Cars? || Green World Blog

Hi Everyone! The previous post in this series really blew up, so thank you so much for your support on that one. In this article, I wanted to discuss why people are not switching to electric cars, and why the transport industry still has a way to go in terms of reaching net zero. If you missed the first part of this post, then  click here to read it! ! I talked in the post linked above, about why people should switch to electric cars, while also taking into account the potential issues with them, and coming to a conclusion about should everyone switch to electric cars. In this post, I wanted to delve further into the topic of why people don't switch to electric cars. The cost is one of the main issues at the moment. To own an electric car, you need a reliable electricity supply, which is not readily available for everyone in the developing world, let alone the cost of buying the vehicle in the first place. The cost of the vehicle coul...