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

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

November Top Tips | sustainable activities and hobbies

Hello everyone, So this week, we are going to be talking about sustainable free time activities. This area can quite big when it comes to environmental impact, so here are some things that you can do in your free time, that are more sustainable. 1. Reading So reading is one of our favourite things to do. However, books are made of paper and the paper industry isn't great. Some ways you can get around this is by reading online (for example, on a kindle), or through borrowing books from a library or using book boxes. If there aren't any in your area then at least try to support independent bookshops! 2. Running If you love being active then this one is for you. Running is probably one of the most sustainable forms of sport. All you need are some running shoes and somewhere to run. There is obviously more high-tech gear but that isn't really necessary if it's just a hobby. 3. Gardening If you've got a small area of land o

Ozone layer

Hi everyone, What even is ozone? And the ozone layer? Where does the hole in the ozone layer come from and what does it mean? Is it dangerous? What can be done? Often the ozone-talk can be complicated and confusing, keeping an overview is hard and understanding all the problems always difficult. Let us break it down a bit for you: What is the ozone layer? We'll start with the basics: The ozone layer is part of the stratosphere, which is the second layer of the Earth's atmosphere, between 10 and 50 km above the Earth's surface and made up of protective gases. One of these protective gases is ozone. There is not much ozone in the atmosphere, only 0.3 molecule of ozone per 1 million molecules of air. This is because ozone is chemically unstable and only forms when ultra violet radiation (UV light) hits oxygen and breaks the bonds between the atoms. It fact it is so unstable that even when it has formed, it breaks down again relatively quickly. This leads to ozone turning back

Zero-waste Challenge

Hi everyone, Welcome back to Green World for our first post of 2024! As explained in our wrap up post, this year the monthly series will switch between challenges and book reviews. We're starting with a challenge and this month we're challenging you to cut down on your waste! 1. No single use plastic bags challenge Plastic bags are a disaster for the environment and they're not always even usable for us. Some of the really thin plastic bags will just rip as soon as you put something in them which is a nightmare if you're out shopping and need to transport your groceries home. When these plastic bags are then thrown away, they cause significant damage to our planet. Plastic bags often clog waterways and sewers which is a massive problem. Waterways, such as streams, and their ecosystems depend on moving water and if they get too blocked, the migration of different species is hindered. If a dam starts to form with all of the sticks, rocks and more plastic that is being tr

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

Autumn Leaves: The science behind one of the most beautiful seasons

Hi everyone! We know that at the time this post is being published it will still be August, and the height of summer here in the Northern Hemisphere, but within the next two months or so, autumn will well and truly be upon us. So, today, we thought we could talk a bit about the science behind this beautiful season. Thinking of autumn automatically brings to mind images of crisp mornings, cosy evenings, and of the picturesque falling leaves with their hues of red, orange, yellow and gold. The change of colour of these leaves marks a change of seasons, and the decreasing temperature and light levels that goes along with that. But why do these leaves lose their greenness and fall from the trees? Trees' leaves contain a chemical called chlorophyll which allows them to convert water and carbon dioxide into glucose, or sugars, through a process called photosynthesis . This is how they gain energy from sunlight. Chlorophyll is green in colour,

Veganism or vegetarianism - are they really sustainable?

Hello everyone Does veganism come with health issues? Is it sustainable? And does vegetarianism change anything? - We're going to be comparing three different diet types: veganism, vegetarianism, and a mixed diet, in multiple categories. This post is structured into the following sections: human rights health area needed animal rights greenhouse gas emissions Which diet is the best? Image and text sources Warning: There are no graphic images in this post. However, in the 'human rights' and 'animal rights' sections, there are descriptions of physical and mental abuse towards both humans and animals. Skip those sections, if you know you can't deal with that. Human rights This may seem like an unrelated topic at first, but in many industries, the rights of people in poorer countries are abused because it's cheaper for the compa

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

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

Sir David Attenborough - an incredible naturalist

Hi everyone and welcome back to Green World, Today we want to talk about one of the most inspiring naturalists of our time. It is, of course, David Attenborough. Today (08.05.2021) is his 95th birthday so we seemed it fitting to publish a post about him today. Over his lifetime, David has won more than 40 awards for his work and was named among the 100 greatest Britons in 2020. David first joined the BBC in 1952 as a producer for the Talks department which looked after all non-fiction broadcasts. Since then, he has worked on lots of different programs and documentaries such as The Life Series, which was first made in 1979. More recently, he has presented Blue Planet and Blue Planet II. The latter had the most views recorded for a single program in 2017. David also gave the Royal Institution's Christmas Lecture in 1973 on The Language of the Animals. David Attenborough is still presenting documentaries to this day. He now lives in Richmo

Green World

Search This Blog