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...

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 ...

10 animals on the edge of extinction you didn't know about no. 9 - South Island takahē

Hello Today we’re talking about the South Island takahē, porphyrio hochstetteri . They are flightless birds, endemic to New Zealand. Takahē are brightly coloured and weigh 2.3-3.8 kg. They have red legs and a large red beak. Their feathers are coloured blue and green. They have wings, but these are only used during courtship or rivalry displays. They are territorial, with one family’s territory reaching anywhere from 4 ha to 100 ha (0,04-1km^2). Pairs will live in the same territory each year. They breed once a year and will raise 1-3 chicks (normally 2) each year. Both parents raise the chicks together. In the wild, takahē live in native grasslands and have a lifespan of 16-18 years. If snow covers the ground then they will move into nearby forests. They eat tussock grasses, sedges and sometimes rushes. But they are opportunists, so they will occasionally go for insects or even ducklings and...

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...

How much do you know about marine animals? | quiz

Hi Everyone! Welcome to another monthly quiz! Today we are so excited to share some quiz questions on marine animals. Let us know how you did in the comments! Questions 1) Which of these came first: sharks, dinosaurs or jellyfish? 2) How many electric bulbs could an electric eel light up? 3) True of False: dolphins sleep with only half their brain. 4) True or False: an octopus has purple blood. 5) What is the loudest sound made by a marine animal (and indeed any animal on the planet!)? 6) True or False: oysters are all female. 7) In which animal species do the males and not the females give birth and care for their young? 8) True or False: a shrimp's heart is in its head. 9) True or False: sea sponges have no head, brain, mouth, eyes, feelers, bones, heart, or lungs. 10) How many continents do turtles live in? Answers: 1) Jellyfish! They've been around for more than 650 million years. 2) 10 3) True! They also...

Pollination

Hello everyone, Today we're talking about pollination and its importance in the world's ecosystems. First a bit of basic plant biology. To reproduce most plants do have a differentiation into male and female, but not in the same way that we see in mammals. Both male and female reproductive organs can be found on the same plant, although not in the same place. Male gametes are produced in the stamens and are then found in pollen. On the other hand, female reproductive organs are called pistils and egg cells are found in the ovule (normally in the flower heads). Pollination describes the process of transporting the pollen to the egg cells, making it an essential part of the reproduction of plants. Nearly all seed plants worldwide require pollination to reproduce. Cone bearing trees also need pollination. Pollination is almost always assisted by other organisms such as insects, birds and mammals to transport the pollen. In some species wind ...

Biodiversity

Hello, Today we're talking about biodiversity and why it's so important. As you probably know biodiversity describes the variety of living species, often referring to one specific place or ecosystem. For example, the Amazon rainforest is a very biodiverse ecosystem. The opposite of biodiverse is a monoculture. A monoculture often refers to farmland, where only one crop is produced. Palm oil plantations are normally monocultures, with rows and rows of palm trees and nothing else. I'm going to start by giving you an idea of the current situation. This year, the State of Nature 2023 report was published. This report looks at recent changes in biodiversity in the UK. To be frank, it's bad news. One in six (17%) of all UK species and almost half (43%) of bird species are at risk of extinction. 31% of amphibians and reptiles and 28% of fungi are also at risk. There has been a 54% decline in flowering plant species and a 34% decline in ...

Carbon credits

Hi everyone, Welcome back to Green World! Today we're talking about an industry that has expanded massively in the past few years. Carbon credits are one of the measures that companies are taking to reduce CO2 emissions . But how does it actually work? The companies that sell carbon credits fund projects to protect an area of forest or rainforest from deforestation . They then calculate how much carbon dioxide emissions they have saves by protecting this area. This means they can now sell 'negative carbon emissions' to companies. In this way, the companies are funding the protection of said area and are causing negative emissions while doing so meaning that the company can still emit greenhouse gases but can claim to be net zero. One carbon credit is basically the permission to emit one ton of CO2. This is good for the company as well as they are able to advertise as sustainable at a relatively low cost to actually reducing the...

Ecotourism: what it is, the advantages and the disadvantages

Hi Everyone! Today we wanted to talk about the idea of ecotourism, including the advantages and disadvantages of this concept. If you are looking to reduce your environmental and social impact when travelling, then this is the post for you! Ecotourism is a form of tourism which limits the damage to the environment and local community. It can involve helping in community projects such as planting trees, as well as taking part in local customs and festivals. It helps to keep the local culture alive, while preserving the natural environment. The advantages are abundant. By helping in a project conserving the environment, tourists gain a new understanding and appreciation for the natural world and may be inspired to make changes in their "real" life to live more sustainably. It provides a valuable insight to a country and community, perhaps also inspiring more respect for different people and the lives they lead. The projects also provide sustainable income sources for locals, h...

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...

Green World

Search This Blog