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

The life of ... an alcon blue butterfly

Hi everyone, Today we are going to be looking into the life of an alcon blue butterfly (Phengaris alcon). After mating, the females lay their eggs on marsh gentian, a blue-coloured wildflower. The eggs can only be laid on these flowers, as this is what the newly hatched caterpillars will eat. Although in some alp regions, they can also be found on willow gentians, a close relative of the marsh gentian. Once the caterpillars have hatched from the eggs, their main predator and danger are the ants that swarm below. But high on their plant homes, the caterpillars are safe. However, this isn't where the alcon blue caterpillars are going to stay forever. Eventually, they drop down to the ground using silk strings. With no protection, they are soon dragged off by the ants. The most amazing part is, the alcon blue caterpillars give off the same scent and chemicals as the ant larvae. So the ants take the caterpillars back to their brood chamber, wher...

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...

Sustainable food choices challenge

Hi everyone, Welcome back to our second challenge! Today we're talking about sustainable food choices.  1. No meat on Mondays challenge The production of meat, especially beef, is resource-intensive and contributes significantly to deforestation, greenhouse gas emissions, and water pollution. By dedicating one day a week to plant-based meals, you can decrease your carbon footprint and help to reduce the strain on natural resources. This challenge encourages a more sustainable and ethical approach to food consumption, gaining a better understanding of the environmental impact of meat production. Reducing meat intake is also associated with health benefits, including lower risks of heart disease and certain cancers, making it a win-win for both your personal well-being and the planet. 2. Local / seasonal eating challenge Choosing local and seasonal foods is important in helping to reduce the environmental impact of food production and transporta...

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...

June 2021 Factfile - some news from the past month, animals and our first plant of the month!

Hi Everyone! We’re terribly sorry for missing last month’s fact file (May). We have all had a busy few months. This is actually the May fact file coming out very late. The June fact file is cancelled. Because of this, this factfile contains news from both months. We are very sorry for the delay in this post. As announced in our last factfile, this post has a new feature to it; plant of the month. We hope you'll enjoy it! News: Sierra Leone has sold a rainforest for a Chinese Harbour Sierra Leone has sold 250 acres of beach and protected rainforest for £39m to build an industrial fishing harbour. It was home to many animals, including several endangered species. This will also have a disastrous impact on local communities, tourism and as I've already mentioned, the environment. Just click  here - It's an article about all the environmental disasters that happened in May. It shocked me. Red Squirrels were born ...

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...

Coral reefs

Hello! We would love to introduce you to the topic of coral reefs and especially coral reef bleaching, as it is a greatly ignored but certainly significant topic. Have fun! 5 coral reef facts 1. The Great Barrier Reef is the largest living structure on the planet and is 2300 km long! 2. Less than 0.1% of the world's ocean surface is covered in coral reefs. 3. At least 25% of all marine animals live there. 4. Coral reefs are often known as the rainforests of the ocean. 5. In 1 square kilometre of coral reef, up to 35 tons of fish can be 'produced'. The 5 biggest coral reefs in the world 1. Great Barrier Reef (near Australia) 2. Red Sea Coral Reef (near Egypt, Israel and Djibouti) 3. New Caledonia Reef (Pacific Ocean near New Caledonia) 4. The Mesoamerican Barrier Reef (near Mexico, Belize, Guatemala and Honduras) 5. Florida Reef (Atlantic Ocean/Gulf of Mexico near Florida) What is coral? Coral is actually made up of small anim...

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 ...

18.10.20 Animal Of The Week: Sloth

Hello, Sorry this didn't come out on Sunday as planned but this week's animal of the week is the sloth because the twentieth of October is Sloth Day.  Habitat The sloth resides in Central and South America. It lives in the rainforests there and occasionally drops into the water for a bathe as, believe it or not, they are actually excellent swimmers! Diet Sloths eat leaves, twigs and buds which they find in the rainforest. As they don't have incisors they smack their lips together to make leaves more digestible. Sloths can survive on relatively little food as it takes a while for them to digest it. Sleep and Speed When you think of a sloth, you probably think of this slow, sleepy creature. They actually sleep for about 15 hours a day! Sloths have an extremely low metabolic rate (what basic calories your body needs to survive), which means they move at a slow pace through the trees. On average, sloths travel 40 yards per day ...

Phytoplankton

Hi everyone, Today we're learning about phytoplankton. Phytoplankton are microscopic organisms that live in both salt and fresh water, and are mostly single-celled plants. The name phytoplankton comes from Greek and means 'drifting/wandering plants'. One of the most well-known phytoplankton species is green algae. Photosynthesis and carbon transport Phytoplankton contains chlorophyll and photosynthesises . This process absorbs carbon dioxide and creates oxygen, which is released into the surroundings. This is so effective that according to a NASA page : "Through photosynthesis, phytoplankton consume carbon dioxide on a scale equivalent to forests and other land plants." Phytoplankton is accountable for the majority of the carbon dioxide that is transferred from the atmosphere to the ocean. This carbon is carried to other ocean layers when the phytoplankton dies and sinks to the ocean floor or is eaten by animals, that then gener...