Watch: Warning: Extreme wildfires set to get worse globally, says UN #wildfires
https://www.youtube.com/watch?v=fJXropdcKoI

Watch: Warning: Extreme wildfires set to get worse globally, says UN #wildfires
https://www.youtube.com/watch?v=fJXropdcKoI&list=PLCUwtp5IghZlGtWhDAkuXVFs8MLdVey75&index=53
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Today's Headlines - 25 July 2023
Marine heat waves gripped world’s oceans
GS Paper - 1 (Geography)

Sweltering temperatures have induced extreme heat warnings, wildfires and poor air quality in different regions. But it isn’t just on the land that the mercury has soared – the average daily global sea surface temperature is off the charts too. Ocean temperatures have remained at record-high levels, giving rise to marine heat waves (MHWs) around the globe.

What are marine heat waves?

A marine heat wave is an extreme weather event. It occurs when the surface temperature of a particular region of the sea rises to 3 or 4 degree Celsius above the average temperature for at least five days.
MHWs can last for weeks, months or even years, according to the US government’s agency National Oceanic and Atmospheric Administration (NOAA).
At present, MHWs have gripped the north-east Pacific, the southern hemisphere in the southern Indian Ocean and the Pacific, the north-east Atlantic, tropical North Atlantic, and the Mediterranean, according to a recent forecast of the non-profit science organisation Mercator Ocean International.
MHWs can have debilitating effects on both marine ecosystems and humans. They may cause the deaths of several marine species, alter their migration patterns, lead to coral bleaching and even impact weather patterns.
MHWs can make storms stronger and severely affect coastal communities. What’s more, these disastrous consequences are set to become even worse as the world continues to get warmer, making MHWs more intense and longer.

What is the impact of marine heat waves on ocean life?

Although an increase of 3 or 4 degrees Celsius in average temperatures may not be much for humans, it can be catastrophic for marine life.
For instance, MHWs along the Western Australian coast during the summer of 2010 and 2011 caused some “devastating” fish kills — the sudden and unexpected death of many fish or other aquatic animals over a short period and mainly within a particular area — as per a 2013 study in the Journal of Marine Systems.
A different study revealed that the same MHWs destroyed kelp forests and fundamentally altered the ecosystem of the coast. Kleps usually grow in cooler waters, providing habitat and food for many marine animals.
Another example is when high ocean temperatures in the tropical Atlantic and Caribbean in 2005 led to a massive coral bleaching event.
Higher ocean temperatures, which are associated with MHWs, can make storms like hurricanes and tropical cyclones stronger.

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Today's Headlines - 16 August 2023
Wildfires ravage Hawaii’s Maui Island
GS Paper - 3 (Environment)

The images of the aftermath of the devastating fire in Hawaii’s Maui Island have grabbed the world’s attention. The wildfires, which have already killed nearly 100 people and left thousands homeless, have become part of a wider global list of unusually intense blazes that have raged across Europe, Canada and the United States.

What happened in Hawaii

Hawaii is no stranger to fires, which burn on a smaller scale with some regularity, especially in the drier parts of the island.
The current fires – active in Lahaina, Upcountry and Pūlehu/Kīhei – are believed to have started with the one in Lahaina spreading quickly across the town.
The exact cause of the fires is still under investigation, but experts agree that the fires were bolstered by strong winds from Category-4 Hurricane Dora, which was passing through the Pacific Ocean – far to the southwest of the island.
Low humidity and dry vegetation too precipitated the issue. Initial reports suggest that the changing land-use patterns in Hawaii, which has seen farm and forest lands being replaced by flammable non-native species of grasses like Guinea grass, are a likely cause for the easy spread of the fire.
Over the past few decades, wildfire has been increasing in Hawaii as a result of changing climate, as a result of increases in invasive species, and a lot of our active agriculture going out… and becoming fallow.

What is the link between wildfires and climate change?

Wildfires have been a part of life on Earth, usually following a seasonal pattern during the June-August period.
Be it natural or human-made, the phenomenon is a critical part of the ecosystem. A healthy fire is key to ensuring that forests remain robust and resilient.
It also aids the natural replenishment of nutrients in the soil, helps sunlight reach the forest floors, and encourages the germination of seeds.
It is the increasingly intense nature of the wildfires – aided by the warming weather, dry conditions and change in rain cycles – that is now becoming a source of worry.
Experts have compared it akin to the difference between throwing a lighted matchstick on a pile of wet, green wood and on dry kindling. And increasingly, climate change is determining the degree of dryness of the latter.
Besides the destruction of lives and livelihoods, these catastrophic wildfires also release an immense amount of carbon dioxide and other greenhouse gases into the atmosphere.
There is also one immediate issue – these immense fires contribute adversely to air pollution, leading to long-term and short-term respiratory issues, heart disease and lung cancer.

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Today's Headlines - 22 August 2023
Extreme heat mean for the Mediterranean Sea
GS Paper - 3 (Environment)

Frequent heat waves cause huge damage to underwater ecosystems and researchers expect more of them in the future.

What are the solutions to heat stress?

Extreme heat has plagued the Mediterranean for weeks. Wildfires raged across at least nine countries in the region from Algeria to Greece.
But the soaring temperatures are not only a danger for people and ecosystems on land; they’re also harming marine life.
Without a doubt global climate change is the main reason for the heat waves in the sea. It’s causing the ocean to warm.
Why are high sea temperatures a problem?

In a warming world, marine creatures are in danger of suffocating. Gases like oxygen and carbon dioxide dissolve better at colder temperatures, so that means the warmer the water; the less oxygen is available to breathe.
Conversely, higher temperatures also cause an increase in metabolism, which in turn means animals have to breathe even more than usual). That combination also heightens the risk of death by starvation for marine life.
The rise in temperature accelerates metabolism, and the organisms need more food to maintain this metabolic rate.
Algal blooms are more common in hotter waters too. Such blooms can further deplete oxygen levels and produce toxins harmful for fish, marine mammals and birds, for instance.
What species and ecosystems are worst hit by marine heat waves?

High water temperatures are most harmful for animals living at the bottom of oceans, lakes or rivers.
These benthic species include corals, mussels, sponges, starfish and plants like sea grasses, and are often attached to rock or solid ground. They can’t migrate when it gets too hot.
Scientists observed mass deaths of benthic species along thousands of kilometers of Mediterranean coastline between 2015 and 2019.
Many benthic species are crucial to the marine ecosystem. They filter the water and keep seas, rivers and lakes clean by eating dead organisms.
Some species are an important food source for other creatures or are harvested by humans. Benthics like soft corals, seaweed and seagrasses provide some of the main ocean habitats.
Heat is particularly harmful for Posidonia oceanica or Neptune grass. And the large, slow-growing seagrass is found only in the Mediterranean. Previous heat waves have decimated the species, which is bad news for the climate.
What does extreme heat in the Mediterranean mean for people?

Warming seas are already affecting fishing activities in the area. Fishermen are catching fewer familiar species and instead are finding more invasive fish which they have difficulty selling.
Rabbitfish and lionfish are edible, but other invasive fish aren’t. Some are even poisonous, like the puffer fish.
Habitat loss could also lead to an overall decline in fish populations, while disappearing seagrass means coasts will be more exposed to future storms.
This could also have a knock-on effect for tourism because divers will be less likely to visit an impoverished underwater landscape.

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Today's Headlines - 23 August 2023
The vegetated canopies for creating green spaces
GS Paper - 3 (Environment)

As Europe battles scorching temperatures this summer and wildfires blaze across the continent from the Mediterranean to Spain, the role of climate change in making heatwaves hotter and more frequent has come into focus. At a broader level, greenhouse gas emissions from human activities have heated the planet by about 1.2 degrees Celsius since pre-industrial times. These grim predictions have brought attention to a range of mitigation measures. One such initiative to bring greenery back to urban spaces in Spain involves installing vegetated awnings or canopies.

What are vegetated canopies?

Introduced in Santa Maria Street in Valladolid, Spain, the awnings are tensioned sail-like structures that have been anchored to the facades of surrounding buildings. They mimic natural canopies found in forests and various plant species.
The lightness and ease of installation of the ‘Greenshades’ allow for shade and the presence of greenery in commercial streets and public spaces, where trees or other vegetation are often absent.
Here is how they work:

The sails with anchors and supports are prepared by laying down the specific geotextile substrate or material. An irrigation system is installed at the highest side, from where the water falls by gravity, soaking the entire substrate.
In addition to water, fertilizer keeps the vegetation in perfect condition. The excess water is collected at the lowest point and into a connected drainage system.
The seed mixture is then projected onto the geotextile. After four months, the shade is expected to be completely covered with vegetation.
The awnings can be placed in streets, where planting trees may not be feasible owing to the lack of space. The plants grow hydroponically, with a water supply point and water outlet for draining purposes.
What are their advantages?

The plants chosen for these awnings belong to species that are optimised for the absorption of gases such as carbon monoxide and nitrogen oxide.
The substrate also absorbs sound waves, reducing noise pollution. A square metre of a vegetated canopy generates the oxygen required by a person for the whole year, apart from filtering harmful gases, according to the company.
The hanging planter also allows for the centralisation of water and light installations.
This is meant to induce savings as the lights are equipped with movement sensors that illuminate the street according to its need.
The adoption of such canopies could eventually contribute to urban biodiversity, creating a healthier ecosystem that supports a variety of wildlife.

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