Category Environment

How climate change can impact bird life?

Migration pattern

The impact of climate change on birds’ migration patterns has been noticed in the last few decades. Scientists have documented that fewer birds show up in breeding and wintering grounds and they attribute it to the increasing temperatures changing vegetation and extreme weather conditions.

Birds synchronise their migratory movements with seasonal changes. The start of their journey and their speed must match the life cycle (before caterpillars pupate) of food sources at the stopover and destination sites. But these environmental cues go for a toss with changing climate.

Lack of food

A number of birds has adjusted breeding times to match early Spring. They arrive at the breeding site earlier than before. Meanwhile, increasing temperatures also make the vegetation bloom and insects hatch earlier at the site. But sometimes these shifts are not in line with each other. As a result, the chicks hatch way after the caterpillars are gone. And so, they starve. (On average the window of time when birds lay their eggs has gotten earlier by almost two weeks over half a century. Since many small songbirds can raise their young in roughly one month, two weeks is a big shift in their timing.)

Habitat loss

One of the major effects of climate change is the loss of habitats. While some species face shrinking ranges, others face habitat destruction. For migrating birds, flooding or desertification could spell doom. Flocks might fly thousands of kilometres only to find their destination submerged or barren. Many goose species use the Siberian tundra’s rocky bedrock to raise their offspring. But increasing temperatures make the permafrost soil to thaw and change the habitat completely, making it impossible for the geese to breed.

Sea-level rise

Sea-level rise and erosion alter coastal wetlands. Many birds, such as piping plovers, that inhabit coastal areas lay their eggs directly on the sand of the beach in a shallow depression. The erosion of beaches and storm surges can cause nests to be lost to the ocean.

Lack of sea ice

Climate change affect penguins in two ways – non-availability of food and nesting habitats. The Adelie penguins nest on land during the summer, and migrate during the winter to the edge of the sea ice, where they feed at sea. As icebergs break off in warming Antarctica, Adelie penguins are forced to take longer routes to find food in the ocean.

Antarctica’s climate is generally cold and dry but warming could cause unprecedented rain or melting of ice, creating puddles on the ground. This is bad news for penguins that lay their eggs on the ground. Their eggs cannot survive when they are lying in a pool of water.

Chinstrap penguins, which also breed in Antarctica, are affected by melting ice. Lack of sea ice affects the abundance of krill their main source of food.

Smaller body, larger wings

A study published in December 2019 found that global warming was causing birds to shrink and their wingspans to grow in size. Scientists explained that it could be more adaptation of birds as smaller birds are better at cooling off, losing body heat more quickly due to their larger surface area to volume ratios. But smaller body size means less energy available for the birds to complete long journeys. Scientists say that birds would have evolved to grow long wings to compensate for their smaller bodies as it helps them survive migration.

Will birds be able to adapt to climate change?

In the past, species and ecosystems were able to respond to global temperature shifts because average global temperatures changed slowly. Now, the change is simply too fast for many species to adapt. As we saw earlier, birds are adapting ways such as starting their migration early to match earlier Springs, but scientists are not sure if they will be able to keep up with the speed of climate change.

 

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How much freshwater do we have?

There’s a good reason our planet is called “the water planet- nearly two-thirds of it is covered in water. To quantify it further, that’s more than 300 million cubic miles of water. That’s quite adequate for humans, isn’t it? Well, not really. Because, 97% of it is in the oceans – salty, undrinkable and not usable for cooking or raising crops. Oh, so we have just 3%? Well, not even that much. Because about 2.5% of that is trapped in glaciers, ice caps, the atmosphere, and soil or is inaccessible because it lies very deep under the Earth’s surface. So that leaves us – over seven billion humans (and wildlife!) – with less than 0.5%. Do you know how little that is? A report says that if all the water in the world can be equated to 100 litres, then all the freshwater we have access to is about half-a-teaspoon! Our drinking and cooking water sources are groundwater, freshwater lakes, rivers, etc Though water can be seen as a renewable resource, the demand for freshwater has been slowly outdoing how much is replenished naturally, especially through the likes of rain. This is indicative not just of imbalance and a changing planet but also of potential global health and political crisis. That wars could be fought over water may not be a problem of a distant future. Which is why there has been consistent and loud calls for water conservation and recycling universally. The impact of water shortage has been showing, and when the problem becomes even more acute it will affect not just humans but also the plants and animals in it and most importantly, our planet itself as a whole.

 

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Can we save Earth?

The history of our planet has been divided into tiny sections of time, and this is called geologic time. Depending on many factors within a specific period, these sections are called eons, eras, periods, epochs, and age. What we now live in is officially called the Holocene (meaning “entirely recent”), an epoch that began more than 11,000 years ago after the last major Ice Age. However, for decades now, many scientists have been calling for a specific name to be given to the epoch that begins mid-20th Century. A name that will sum up how intensely and singularly we humans have altered our planet – Anthropocene (anthropo meaning “human” and cene, “new”). Mid-century was chosen because that’s when the first atomic bomb exploaded leaving behind radioactive debris in sediments and glacial ice, “becoming part of the geologic record”. While we do not know if Anthropocene will be officially accepted and adopted, what we can be sure of is that our actions are directly responsible for how the Earth is today. In fact, we’re in the midst of the sixth mass extinction – the first one for which humans are to blame! But many are still hopeful that we can work collectively to save the planet despite the window of opportunity closing really fast.

 

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What is the impact of supercontinents on climate?

Our planet did not always have seven continents.  surprised? Our universe began with the Big Bang about 14 billion years ago, and Earth was formed about 4.5 billion years ago. During its history. Earth has witnessed the coming together and the breaking up of its land masses several times, A single large land mass is called a supercontinent. There have been many supercontinents so far. The youngest supercontinent is Pangaea, formed more than 300 million years ago. This is said to have been formed when two land masses Euramerica and Gondwana – collided. Pangaea began to break up nearly 175 million years ago, and gradually fomed the world as we know it today – Gondwana became Africa, South America, Antarctica, India and Australia, and North America split from Europe. This tremendous geographical alteration also means great impact on the environment climate and biodiversity. For instance, the collision of land masses results in the creation of large mountain chains, which directly impact the dimate in the region. Also, when only one large land mass exists, the most interior regions are far removed from oceans and experience dry weather. However, when the land mass breaks up, many regions earlier in the central part get surrounded by water, altering weather patterns over a period of time. Studies also show that broken-up continents “create more ecological niches and promote favorable dimate and environmental conditions that are conducive to biodiversity” A study said that “marine species tend to become more numerous when the continents divide”, and come down in great numbers when continents come together – a small example of a supercontinent’s direct impact on biodiversity.

 

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How do floods happen?

Many floods happen when it rains very heavily and rivers overflow. They burst their banks and flood the land all around. You also get floods in stormy weather when high tides or gigantic waves sweep on to the shore.

Amazing! The Thames Barrier was finished in 1984 to stop the River Thames flooding and drowning London. Ten huge steel gates swing up to make a massive dam.

What are flash floods?

Flash floods are floods which happen very suddenly, with no warning. Sometimes there isn’t time to evacuate buildings in the flood’s path. Flash floods can happen in the desert too, during a rare downpour of rain.

Is it true? Floods can wash whole buildings away.

Yes. In 1955, a flood in the USA washed a four-storey wooden hotel clean away. Imagine how surprised the guests were when they looked out of their windows!

Are some floods useful?

Yes, they are. The River Nile in Egypt used to flood every year, leaving rich mud on the fields. The mud made the soil ideal for farmers to grow bumper crops. The Nile doesn’t flood anymore because a large dam was built to store its water.

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From Kerala to Assam, floods cause widespread damage

The one word used repeatedly to describe several natural events across the world this year has been “unprecedented”. And it is no different for rains and subsequent floods. Be it Assam and Kerala in India, neighbours China, Bangladesh and Nepal or far away Africa and the U.S., the quantum of rain dumped so far has been unheard of, resulting in floods and landslides. And it did not help that these rains have come in the midst of the pandemic, rendering a twin blow to the people. According to new reports, monsoon rains this season have affected about 10 million people in South Asia alone, and this includes 1.3 million in Assam. In September, large areas of Africa witnessed rains with intensity not recorded earlier. In mere seven hours, Senegal recorded an amount of rain that usually takes an entire rainy season from July to September! Such a crisis causes loss of not just human lives but also of wildlife. Assam’s Kaziranga National Park lost more than a 100 wild animals, including about a dozen endangered one-horned rhinoceros in the recent floods. Rains and floods also damage or change landscapes permanently, in the process shrinking or destroying wildlife habitats and causing ecological imbalance. Experts point out that extreme weather event could be a result of human-induced climate change. This change is so swift and continuous that it does not allow for nature to heal or recover, threatening to trigger irrevocable consequences for the entire planet and all of its inhabitants.

Did you know?

This July, a few residents of Assam were greeted by an unusual visitor or two – one-horned rhinoceros (occasionally with a little one in tow) escaping Pobitora Wildlife Sanctuary, about 90% of it flooded by the swelling Brahmaputra. The sanctuary has the distinction of nurturing the highest density of rhinos in the world. But it also means these pachyderms jostle for space. And floods certainly don’t help. So the fortunate and smart among the lot moved to the fingers of the sanctuary and made themselves comfortable at the houses there – rent-free! While some residents were thrilled, some weren’t. However, no instances of human-animal conflict were reported.

 

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