New Delhi:

More than 85 per cent of districts in India are exposed to extreme climate events such as floods, droughts and cyclones, according to a new study.

The study by IPE Global and Esri India also found that 45 per cent of the districts were experiencing a “swapping” trend, where traditionally flood-prone areas were becoming drought-prone and vice versa.

Using a penta-decadal analysis, the study compiled a catalogue of extreme climate events during a 50-year period from 1973 to 2023, employing spatial and temporal modelling.

The last decade alone saw a five-fold increase in these climate extremes, with a four-fold increase in extreme flood events, it said.

Districts in eastern India are more prone to extreme flood events, followed closely by the country’s northeastern and southern parts.

The study also shows there has been a two-fold increase in drought events, especially agricultural and meteorological droughts, and a four-fold increase in cyclone events.

It found that more than 60 per cent of districts in Bihar, Andhra Pradesh, Odisha, Gujarat, Rajasthan, Uttarakhand, Himachal Pradesh, Maharashtra, Uttar Pradesh and Assam were experiencing more than one extreme climate event.

Abinash Mohanty — head of climate change and sustainability practice at IPE Global and the study’s author — said, “The current trend of catastrophic climate extremes that makes nine out of 10 Indians exposed to extreme climate events is a result of a 0.6 degree Celsius temperature rise in the last century.” “Recent Kerala landslides triggered by incessant and erratic rainfall episodes, floods in Gujarat, the disappearance of Om Parvat’s snow cover, and cities getting paralysed with sudden and abrupt downpours is a testament that climate is changed. Our analysis suggests that more than 1.47 billion Indians will be highly exposed to climate extremes by 2036,” he said.

The study revealed that more than 45 per cent of districts were experiencing a swapping trend, ie, some flood-prone districts were becoming more susceptible to droughts and vice versa.

The number of districts that have transitioned from experiencing floods to facing droughts surpassed those that have shifted from droughts to floods.

Districts in Tripura, Kerala, Bihar, Punjab and Jharkhand exhibit the most prominent swapping trends, it said.

The study recommended establishing a Climate Risk Observatory, a risk-informed decision-making toolkit for policymakers at the national, state, district and city levels under its National Resilience Programme, and the creation of an Infrastructure Climate Fund to support sustained investment in climate-resilient critical infrastructure and foster locally-led climate actions.

Ashwajit Singh, founder and managing director of IPE Global, said, “To meet climate goals, India must shift its budget focus from mitigation to adaptation. Current practices underfund climate resilience, risking long-term sustainability. India, in particular, experienced an 8 per cent GDP loss in 2022 and a cumulative capital wealth decrease of 7.5 per cent due to climate impacts.” Agendra Kumar — Esri India’s managing director — said the increasing frequency and intensity of heat waves, in conjunction with intense precipitation, was causing significant impacts on lives, livelihoods and infrastructure.

A holistic, data-driven approach is essential for informed policy decisions, climate adaptation and resilience, he said.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Incessant rainfall has wreaked havoc in India’s southeast, leaving at least 17 dead in Andhra Pradesh and thousands homeless and at the mercy of floods in Telangana.

The Indian Meteorological Department has also warned of heavy rains in parts of Gujarat, Himachal Pradesh, and Delhi. 

Unpredictable, erratic rainfall has been becoming the norm for the Indian monsoon. Once a bringer of relief and hope to the subcontinent, these rains are now a herald of drought and floods.

Climate change is an important reason why. However, a closer look into climate models shows the intricate play of surface temperature, pressure gradients, air currents and even sea ice that is responsible for bringing rain to the Indian landmass. 

In a study published in the journal Remote Sensing of Environment in June, researchers from India’s National Centre for Polar and Ocean Research (NCPOR), under the Ministry of Earth Sciences, and South Korea’s Korea Polar Research Institute have found that seasonal changes in the Arctic sea ice affect the Indian monsoon as well.

What is the Indian Summer Monsoon Rainfall?

The Indian summer monsoon rainfall (ISMR) over the Indian subcontinent, from July to September, and with most of the rains recorded in July and August, is one of the most prominent monsoon systems in the world.

In summer months, sunlight warms the Central Asian and Indian landmass more and faster than the surrounding ocean. This creates a low pressure band at the Tropic of Cancer called the intertropical convergence zone.

Trade winds blowing from the southeast are subsequently deflected towards the Indian landmass due to the Coriolis force and the low pressure after they cross the equator. As they blow over the Arabian Sea, the winds pick up moisture and deposit that as rain over India.

Over the landmass itself, this southwest monsoon splits into two. The Arabian Sea arm brings rain to the west coast while the other arm travels to the Bay of Bengal and brings rain to India’s eastern and northeastern parts.

The arms finally converge over Punjab and Himachal Pradesh as the Arabian Sea arm moves inward and the Bay of Bengal arm moves along the Himalaya. 

The ISMR is much more complex than scientists first anticipated. In the last two decades, climate models have shown that the surface temperatures of the Indian, the Atlantic, and the Pacific Oceans affect the ISMR. The circum-global teleconnection (CGT), a large-scale atmospheric wave flowing at the mid-latitudes, seemed to significantly influence the monsoon as well.

How does Arctic sea ice influence the Indian monsoon?

In recent years, scientists have also suggested that declining levels of Arctic sea ice, due to climate change, could influence the monsoon’s temperament, too.

In the new study, researchers used observational data from 1980 to 2020 and climate models (specifically Coupled Model Intercomparison Project Phases 5 and 6) to check how the Arctic sea ice levels affect atmospheric circulations that in turn influence the ISMR.

The results revealed distinct and at times contrasting patterns. According to the paper, less sea ice in the central Arctic leads to lower rain in western and peninsular India but more rain in central and northern India.

On the other hand, lower sea ice levels in the upper latitudes, particularly in the Barents-Kara Sea region encompassing the Hudson Bay, the Gulf of St. Lawrence and the Sea of Okhotsk, delay the monsoon’s onset and render it more unpredictable.

Several atmospheric systems also influence this pattern. The scientists found that when sea ice levels in the Central Arctic increase, the heat transferred from the ocean to the atmosphere triggers a cyclonic circulation at slightly lower latitudes, like in the North Atlantic.

This bolsters the Rossby waves, fast-flowing streams of air high in the atmosphere created by the earth’s rotation and differences in temperature and weather systems that move west to east.

“To put it simply, imagine giant loops in a river of air high above us. These loops can push warm or cold air across the planet and steer storms around, changing weather patterns as they go,” Avinash Kumar, an NCPOR scientist and one of the study’s coauthors, told The Hindu.

The enhanced Rossby waves result in high pressure over northwest India and low pressure over the Mediterranean region. This in turn strengthens a narrow, concentrated band of wind, called the Asian jet stream, over the Caspian Sea, causing the subtropical easterly jet — a jet stream blowing over the Indian subcontinent during summer — to shift northward.

As a result, an anomalous high pressure region is created over Central Asia, disrupting atmospheric stability over the Indian landmass and bringing more rain over western and peninsular India.

On the other hand, low sea ice over the Barents-Kara Sea region triggers a series of air currents that produce an anomalous high pressure over southwest China.

This correlates with a positive Arctic Oscillation — high pressure over the northern Atlantic and Pacific oceans along with a weakening of the CGT, which connects weather events in different parts of the world. 

As sea ice levels decrease in the region, heat rises from the Barents-Kara sea, creating an anticyclonic circulation (calm, clear skies) over northwest Europe. This disturbs the upper atmospheric region over subtropical Asia and India.

This instability, coupled with high surface temperature of the Arabian Sea and the moisture picked up from the surrounding water bodies promotes high rainfall over northeastern India while leaving central and northwest regions of the country without much

Does climate change also play a role?

Now that scientists know a little more about the forces that conspire to bring or withhold rain over India, what can we say about the role of climate change?

“Climate change, by accelerating the reduction of Arctic sea ice, exacerbates the variability and unpredictability of the ISMR,” Dr. Kumar said. “Lower Arctic sea ice can lead to more frequent and severe droughts in some regions while causing excessive rainfall and flooding in others.”

Apart from highlighting the physical pathways in which the Arctic sea ice affects the Indian monsoon, the current study shows the urgent need to expand research on climate dynamics and for scientists to prepare more accurate forecasts of the ever-changing monsoons. 

Tracking rising temperatures is becoming a better way of forecasting food inflation in India than the rain patterns economists have typically relied on, according to HSBC Holdings Plc.

The link between extreme heat, exacerbated by climate change, and the price of agricultural commodities in India has strengthened over the past decade, the bank said in a report released Thursday. The correlation between temperatures and cost of perishable staples such as fruit and vegetables in the country rose to 60% this year from 20% in 2014, it said.

Inflation remains well above the Reserve Bank of India’s 4% target due to volatile food costs, prompting the authority to hold its policy rate for the last year and a half.

HSBC said it expects consumer-price gains to ease toward the end of the year as temperatures drop after the summer heat wave. But “over the medium term, rising temperatures could become a big problem for inflation management,” it said.

Analysts used to estimate food inflation changes by looking at the levels of India’s reservoirs, a measure that the bank’s economists said may soon become obsolete.

This is possibly due to improved irrigation systems that mitigate the impacts of scarce rainfall, while there is currently no solution to shield crops from extreme heat, they said.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

A hole filled with water from melted ice is seen among black rock and ice on the Rhone glacier amid climate change in Obergoms, Switzerland, August 27, 2024.
| Photo Credit: Reuters

As humans alter the planet’s climate and ecosystems, scientists are looking to Earth’s history to help predict what may unfold from climate change. To this end, massive ice structures like glaciers serve as nature’s freezers, archiving detailed records of past climates and ecosystems – including viruses.

We are a team of microbiologists and palaeoclimatologists that studies ancient microorganisms, including viruses preserved within glacier ice. Along with our colleagues Lonnie Thompson, Virginia Rich and other researchers at the Ice Core Paleoclimatology group at The Ohio State University, we investigate interactions between viruses and their environment archived in ice cores from the Guliya Glacier on the Tibetan Plateau.

By linking the genomes of ancient viral communities to specific climate conditions preserved in glacier ice, our newly published research offers insights into how these viruses have adapted to Earth’s shifting climate over the past 41,000 years.

Reading history in viral genes

We primarily used metagenomes – collections of genomes that capture the total genetic content of all microorganisms present in environmental samples – to reconstruct viral genomes from nine distinct time intervals within the Guliya ice core. These time horizons span three major cold-to-warm cycles, providing a unique opportunity to observe how viral communities have changed in response to different climatic conditions.

Through our analyses, we recovered the genomes of the equivalent of 1,705 virus species, expanding known glacier-preserved ancient viruses more than fiftyfold.

Only about one-fourth of the viral species we found shared species-level similarities with any of the viruses identified in nearly 1,000 metagenomes previously captured in global datasets. Most of these overlapping species were also from the Tibetan Plateau. This suggests that at least some viruses preserved in the Guliya Glacier originated locally in the region, but it also spoke to the relative lack of glacial viruses in available databases.

Using these new reference genomes, we attempted to “read” their stories.

One key finding was that viral communities varied significantly between cold and warm climatic periods. The most distinct community of viral species on the glacier appeared about 11,500 years ago, coinciding with the major transition from the Last Glacial Stage to the Holocene. This suggests that the unique climate conditions during cold and warm periods profoundly influenced the composition of viral communities. We hypothesize that these influences were likely due to viruses from other places being blown in by changing wind patterns and subject to selection pressures from changing temperatures on the glacier.

Digging deeper, we next determined how viruses interacted with their hosts. To do this, we used computer models to compare viral genomes with the genomes of other microbes also found in this environment. We found that viruses consistently infected Flavobacterium, a lineage of bacteria commonly found in glacier environments.

We also learned that viruses on the Guliya Glacier must “steal” genes from their hosts to manipulate their metabolisms. Encoded within the viral genomes were 50 auxiliary metabolic genes related to metabolism, including the synthesis and breakdown of vitamins, amino acids and carbohydrates. Some of these genes were abundant across all nine time intervals studied, suggesting that they help microbial hosts cope with the harsh conditions on glacier surfaces and thereby improve viral fitness.

Thus, viruses not only infect and kill cells, but they likely also alter the fitness of their hosts during infection, in turn influencing their capacity to survive in the extreme conditions of glacier environments.

Climate change over time

Our findings offer a novel perspective on how life, in the form of viruses, has responded to climatic changes over tens of thousands of years.

Understanding these ancient interactions provides a unique opportunity for future research in both virology and climate science. By studying how ancient viruses responded to past climate changes, researchers can gain valuable insights into how viruses adapt to ongoing global climate change.

We believe that glacier ice, by capturing information on microorganisms and their ecosystems over time in each layer, remains a critical resource for unraveling the history of Earth’s climate and the life it has supported – especially as glacier ice reserves rapidly diminish.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A researcher breeds the new heat-resistant rice called “Emihokoro” or “Beaming Smile” at the government-run Saitama Agricultural Technology Centre in Kumagaya, Saitama prefecture, Japan, August 7, 2024.
| Photo Credit: Reuters

Grappling with a rice shortage after extreme weather ravaged last year’s crop, Japan is hoping new heat-resistant varieties of its staple food can help stave off future supply shocks.

Last summer’s high temperatures and dry conditions led to lower rice yields in key growing regions and damaged the quality of grains, contributing to the lowest inventories seen in 25 years, according to official data.

Along with higher demand – partly attributed to record inbound tourism this year – supermarkets across the country have struggled to keep rice shelves stocked in recent months and some have imposed quotas on how much customers can buy.

The local government in Saitama, a prefecture north of Tokyo that is one of the hottest regions in the country, hopes science can avert future shortages and is pushing ahead with one of several nationwide projects to develop more resilient rice.

“It’s going to keep getting hotter, which makes me feel that without varieties that resist high temperatures, this is going to become a very tough job,” said Yoshitaka Funakawa, a 73-year-old farmer who is participating in the trial run for Saitama’s heat-resistant rice called emihokoro or ‘beaming smile’.

Japan sweltered in its warmest July on record in 2024.

High heat disrupts the accumulation of starch inside rice grains, causing them to appear more opaque, mottled with white flecks and less desirable for human consumption, impacting the crop’s market value.

“The more this cloudy, white phenomenon there is on rice, the grade of rice decreases, which leads to declines in farmers’ income,” said Naoto Ooka, who oversees rice breeding at Saitama’s Agricultural Technology Research Centre.

At the centre, researchers take seeds from across Japan, cultivate and cross-pollinate them in a drive to create more resistant varieties like emihokoro, which has been planted in 31 fields as a trial this year.

Rice is a source of pride for Japan, renowned for premium grains that are the base for signature dishes like sushi, but it is also a widely consumed food.

Rice is also one of the few staples the nation has historically been able to be self-sustainable in producing. The world’s fourth-largest economy imports more than 60% of its food resources.

Last year’s poor yields are among the factors that have driven up prices sharply.

Private rice inventories in Japan amounted to 1.56 million tonnes in June 2024, the lowest end-of-season volume since 1999 when comparable data was first collected, according to the agriculture ministry.

Inflation data for July released last week showed rice, excluding the famous ‘koshihikari’ premium brand, saw the highest rate of price increase in over 20 years.

At a branch of the Akidai supermarket chain in western Tokyo, shelves normally stocked with bags of rice were largely empty.

The supermarket chain’s president Hiromichi Akiba said wholesalers have been unable to fulfil its orders, and sometimes they cannot deliver any rice.

While the current shortage may be relieved when a new crop becomes available as early as September, tight supply is expected to remain through next year with hot weather posing risks for upcoming harvests, research firm BMI said in a report this month.

Meanwhile, the government is increasingly concerned that climate change will threaten its most important crop longer term unless action is taken.

An agriculture ministry report released in July showed paddy rice yields in Japan are projected to decline about 20% by 2100 compared to the previous century.

The ministry said shifting to high temperature-tolerant varieties was the most important measure to address the impact of climate change on rice crops and possible future shortages.

An iceberg floats near Two Hummock Island, Antarctica, February 2, 2020. Picture taken February 2, 2020.
| Photo Credit: Reuters

Nearly 1,500 academics, researchers and scientists specialising in Antarctica gathered in southern Chile for the 11th Scientific Committee on Antarctic Research conference this week to share the most cutting-edge research from the vast white continent.

Nearly every aspect of science, from geology to biology and glaciology to arts, was covered but a major undercurrent ran through the conference. Antarctica is changing, faster than expected.

Extreme weather events in the ice-covered continent were no longer hypothetical presentations, but first-hand accounts from researchers about heavy rainfall, intense heat waves and sudden Foehn (strong dry winds) events at research stations that led to mass melting, giant glacier break-offs and dangerous weather conditions with global implications.

With detailed weather station and satellite data dating back only about 40 years, scientists wondered whether these events meant Antarctica had reached a tipping point, or a point of accelerated and irreversible sea ice loss from the West Antarctic ice sheet.

“There’s uncertainty about whether the current observations indicate a temporary dip or a downward plunge (of sea ice),” said Liz Keller, a paleoclimate specialist from the Victoria University of Wellington in New Zealand that led a session about predicting and detecting tipping points in Antarctica.

NASA estimates show the Antarctic ice sheet has enough ice to raise the global mean sea level by up to 58 meters. Studies have shown that about a third of the world’s population lives below 100 vertical meters of sea level.

While it’s tough to determine whether we’ve hit a “point of no return,” Keller says that it’s clear the rate of change is unprecedented.

“You might see the same rise in CO2 over thousands of years, and now it’s happened in 100 years,” Keller said.

Mike Weber, a paleooceanographer from Germany’s University of Bonn, who specialises in Antarctic ice sheet stability, says sediment records dating back 21,000 years show similar periods of accelerated ice melt.

The ice sheet has experienced similar accelerated ice mass loss at least eight times, Weber said, with acceleration beginning over a few decades that kick off a phase of ice loss that can last centuries, leading to dramatically higher sea levels around the world.

Weber says ice loss has picked up over the last decade, and the question is whether it’s already kicked off a centuries-long phase or not.

“Maybe we’re entering such a phase right now,” Weber said. “If we are, at least for now, there will be no stopping it.”

Keeping emissions low

While some say the climate changes are already locked in, scientists agreed that the worst case scenarios can still be avoided by dramatically reducing fossil fuel emissions.

Weber says the earth’s crust rebounds in response to retreating glaciers and their diminishing weight could balance out sea level rise, and new research published weeks ago shows that a balance is still possible if the rate of change is slow enough. “If we keep emissions low, we can stop this eventually,” said Weber. “If we keep them high, we have a runaway situation and we cannot do anything.”

Mathieu Casado, a paleoclimate and polar meteorologist at France’s Climate and Environment Sciences Laboratory, specialises in studying water isotopes to reconstruct historical temperatures.

Casado said data from dozens of ice cores collected throughout the ice sheet has allowed him to reconstruct temperature patterns in Antarctica dating back 800,000 years.

Casado’s research showed that the current temperature rise in the last fifty years was clearly outside natural variability, highlighting the role of industry in producing carbon emissions that drive climate change.

He added that the last time the Earth was this warm was 125,000 years ago and sea levels were 6 to 9 meters higher “with quite a bit of contribution for West Antarctica.”

Temperature and carbon dioxide were historically at equilibrium and balanced each other out, Casado said, but we currently have much higher levels of CO2 and are far from equilibrium.

Casado and other scientists noted the speed and quantity at which carbon is being pumped into the atmosphere is unprecedented.

Gino Casassa, a glaciologist and head of Chilean Antarctic Institute, said that current estimates show sea levels rising by 4 meters by 2100 and more if emissions continue to grow.

“What happens in Antarctica doesn’t stay in Antarctica,” said Casassa, adding that global atmospheric, ocean and weather patterns are linked to the continent.

“Antarctica isn’t just an ice refrigerator isolated from the rest of the planet that has no impact.”

An activist from Youth 4 Climate Action Yoon Hyeonjeong looks on during an interview with Reuters in Seoul, South Korea, August 28, 2024.
| Photo Credit: Reuters

Yoon Hyeonjeong, a 19-year-old South Korean activist, says the fate of her years-long fight for more action to tackle climate change hinges on what could be a landmark ruling by the country’s top court on Thursday.

Yoon is among about 200 plaintiffs, including young environmentalists like herself and even infants, in petitions filed to the Constitutional Court since 2020, which argue the government is violating its citizens’ human rights by not effectively tackling climate change.

Climate advocacy groups say it will be the first high court ruling on a government’s climate action in Asia, potentially setting a precedent in a region where similar lawsuits have been filed in Taiwan and Japan. In April, Europe’s top human rights court ruled the Swiss government had violated the rights of its citizens by failing to do enough to combat climate change.

“Picketing on streets, policy proposals, these campaigns weren’t enough to bring about real changes,” said Yoon, who is hoping the court ruling will help tear down bureaucratic hurdles on climate policy.

Lawyers for the government say authorities are doing everything possible to cut carbon emissions.

Han Wha-jin, who was environment minister, said in May the government’s emission reduction targets did not infringe on people’s rights, though the constitutional petition provided a public forum about the severity of the climate crisis.

In 2019, Yoon was in her third year of middle school when she watched a climate crisis documentary that she said shocked her into action.

Despite not being particularly outgoing, she decided to try and follow in the footsteps of the likes of Greta Thunberg, a Swedish climate activist who has inspired a global youth movement demanding stronger action against climate change.

Yoon wrote slogans with crayons to picket at schools, telling her elders to stop destroying the planet. She later dropped out of high-school and left her hometown to focus on the climate movement in the capital Seoul.

South Korea’s constitutional court does not award damages or order law enforcement measures but can rule existing laws are unconstitutional and request parliament to revise them.

Germany‘s constitutional court ruled in 2021 the country must update its climate law to set out how it will bring carbon emissions down to almost zero by 2050.

Scientists say a global temperature rise beyond 1.5 degrees Celsius (2.7 degrees Fahrenheit) above the preindustrial average will trigger catastrophic and irreversible impact on the planet, from melting ice sheets to the collapse of ocean currents.

South Korea is seeking to reach carbon neutrality by 2050, but remains the second-highest coal polluter among G20 countries after Australia, data showed, with slow adoption of renewables.

The country last year revised down its 2030 targets for greenhouse gas reductions in the industrial sector but kept its national goal of cutting emissions by 40% of 2018 levels.

Calling for an end to the use of fossil fuel, Yoon said flooding and rising temperatures caused by climate change were having immediate effects on people’s lives.

“We already have tools to cut carbon emissions. That is, stop using fossil fuels,” she said.

Over 90% of plastic is not recycled, with much of it dumped in nature or buried in landfills. File
| Photo Credit: AP

With months until crunch talks on the world’s first binding treaty on plastic pollution, experts are meeting in Bangkok to discuss financing options and problematic plastics.

The four-day gathering is a largely technical waypoint on the road to final negotiations in late November in South Korea’s Busan.

There, countries are hoping to seal a potentially groundbreaking deal to tackle the gargantuan problem of plastic pollution.

The scale of the issue is almost unprecedented – microplastics have been found in the deepest ocean trenches, highest mountain peaks, in clouds and even breastmilk.

Plastic production has doubled in 20 years and at current rates it could triple by 2060, according to the Organisation for Economic Cooperation and Development (OECD).

Yet over 90% of plastic is not recycled, with much of it dumped in nature or buried in landfills.

Negotiators have already met four times to discuss a deal that could include production caps, unified rules on recyclability, and even bans on certain plastics or chemical components.

But significant gaps remain, including on whether the treaty will be adopted by consensus or a majority vote.

“Other flashpoints include whether plastic production will be addressed,” Eirik Lindebjerg, global plastics policy lead at WWF, told AFP.

“Is it within the scope to talk about production, or does the value chain start after plastic products are made? And then if we can regulate production… is it with a cap, is it with a reduction target, what are the measures?” he said. “That’s been a very contentious issue.”

Environmental groups have long argued that the treaty must include curbs on new plastic, a position backed by dozens of countries who call themselves the “high ambition coalition”.

They may now have a powerful ally in the form of the United States, which has reportedly thrown its backing behind some production limits.

That shift has been welcomed by environmental groups, though Mr. Lindebjerg warned it was not yet clear if Washington would back mandatory caps or weaker voluntary limits.

‘Unresolved matters’

Just how binding the deal will be is another source of contention.

Some countries want measures like a unified timeline for phasing out certain plastics, while others back vaguer language that would let nations decide how and when to regulate.

And, as with climate negotiations, finance for implementing whatever is agreed remains hugely controversial.

“Some countries want money, and some countries don’t want to give money, very simply put,” said Mr. Lindebjerg.

Two expert groups are meeting in Bangkok, with one focused on financing, including technical details on waste management systems and how to implement “polluter pays” principles.

The second group will focus on a framework and criteria for chemicals, plastic materials and plastic products that could be targeted for bans or reductions in the treaty.

The meetings are advisory and are being held behind closed doors, to the dismay of some environmental groups and industry.

“There are still a lot of unresolved matters,” warned Chris Jahn, council secretary of the International Council of Chemical Associations, which represents the global chemical industry.

The group opposes language that would regulate chemicals or cap plastic production.

“Plastics are essential in order for the world to achieve its sustainable development and climate change goals,” Mr. Jahn said, pointing to uses from solar energy to food preservation.

The American Chemistry Council last week warned U.S. backing for production caps would “betray” U.S. manufacturing and risk jobs.

“The industry does back efforts to promote the reuse of plastics and new designs to make recycling easier,” Mr. Jahn said, “as well as rules to make producers pay for plastic pollution.

And despite the remaining gaps, there is cautious optimism that a robust deal is possible.

“I think that we’re really at a historic opportunity here,” said Mr. Lindebjerg.

Algae floats on the surface of Lake Erie’s Maumee Bay in Oregon, Ohio, on Friday, September 15, 2017. Scientists found prokaryotes are remarkably resilient to climate change – and as a result, could increasingly dominate marine environments.
| Photo Credit: AP

The world’s oceans are home to microscopic organisms invisible to the human eye. The tiny creatures, known as “prokaryotes”, comprise 30% of life in the world’s oceans.

These organisms play an important role in keeping the oceans in balance. But new research by myself and colleagues shows this balance is at risk.

We found prokaryotes are remarkably resilient to climate change – and as a result, could increasingly dominate marine environments.

This could reduce the availability of fish humans rely on for food, and hamper the ocean’s ability to absorb carbon emissions.

A fine balance

Prokaryotes include both bacteria and “archaea”, another type of single-celled organism.

These organisms are thought to be the oldest cell-based lifeforms on Earth. They thrive across the entire planet – on land and in water, from the tropics to the poles.

What prokaryotes lack in size they make up in sheer abundance. Globally, about two tonnes of marine prokaryotes exist for every human on the planet.

They play a crucial role in the world’s food chains, helping support the nutrient needs of fish humans catch and eat.

Marine prokaryotes grow extremely fast – a process that emits a lot of carbon. In fact, prokaryotes to an ocean depth of 200 metres produce about 20 billion tonnes of carbon a year: double that of humans.

This massive carbon output is balanced by phytoplankton – another type of microscopic organism which turns sunlight and carbon dioxide into energy, through photosynthesis.

Phytoplankton and other ocean processes also absorb up to one-third of the carbon humans release into the atmosphere each year. This helps limit the pace of global warming.

How prokaryotes respond to warming is key to understanding how the fine balance of the world’s oceans may change in a warmer world. This was the focus of our research.

What we found

We wanted to predict how climate change would affect the “biomass”, or total global weight, of marine prokaryotes. We also wanted to examine how it would affect their carbon output.

To do this, we built computer models that integrated decades of observations from dozens of scientific surveys across the world’s oceans.

So what did we find? Prokaryotes are likely to be climate change winners, relative to other marine life.

For each degree of ocean warming, their biomass will decline by about 1.5%. This is less than half the projected 3–5% decline we predicted for larger plankton, fish and mammals.

It means future marine ecosystems will have lower overall biomass, and will increasingly be dominated by prokaryotes. This could divert a greater share of available nutrients and energy toward prokaryotes and away from fish, reducing the supply of fish humans eat.

We discovered another important change. For every degree of warming, we predict prokaryotes in the top 200 metres of the world’s oceans would produce an additional 800 million tonnes of carbon per year.

This is equivalent to the present-day emissions of the entire European Union (after converting CO₂ to carbon).

What does all this mean?

Due to human-caused climate change, Earth’s oceans are expected to warm by between 1°C and 3°C by the end of this century, unless humanity changes course.

If the amount of carbon produced by prokaryotes does increase as predicted, it could reduce the potential of oceans to absorb human emissions. This means achieving global net-zero emissions will become even more difficult.

What’s more, present projections of declines in global fish stocks under climate change generally do not consider how warming may restructure marine food webs by favouring prokaryotes. This means the predicted declines are likely to be underestimated.

Declines in fish populations present a major problem for global food supply, because the oceans are a major source of protein for about 3 billion people.

What should happen now

Our analysis is an important step in uncovering the changing role of marine prokaryotes. But significant uncertainties remain.

Our analysis is built with existing observations. Climate change is already changing conditions in marine ecosystems in ways our models may not have captured.

We also don’t know how quickly prokaryotes will adapt and evolve to new environments. But existing research shows that in a matter of weeks, bacteria can develop new traits that make it easier for them to survive.

Clearly, scientists must continue to improve their understanding of prokaryotes, and how they may be affected by climate change.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

New Delhi:

The deadly landslides in Kerala’s ecologically fragile Wayanad district were triggered by a heavy burst of rainfall, made 10 per cent heavier by climate change, according to a new rapid attribution study by a global team of scientists.

The team of 24 researchers from India, Sweden, the US and the UK said that more than 140 mm of rainfall fell in a single day on soils highly saturated by two months of monsoon precipitation, triggering catastrophic landslides and floods that killed at least 231 people in Wayanad.

“The rainfall that triggered the landslides occurred in a region of Wayanad that has the highest landslide risk in the state. Even heavier downpours are expected as the climate warms, which underscores the urgency to prepare for similar landslides in northern Kerala,” Maja Vahlberg, a climate risk consultant at the Red Cross Red Crescent Climate Centre, said.

To measure the impact of human-caused climate change, the scientists from the World Weather Attribution (WWA) group analysed climate models with high enough resolution to accurately reflect rainfall in the relatively small study area.

The models indicated that the intensity of rainfall has increased by 10 per cent due to climate change, they said.

The models also predict a further four per cent increase in rainfall intensity if the average global temperature rises by two degrees Celsius compared to the 1850-1900 average.

The scientists, however, said there is a “high level of uncertainty” in the model results as the study area is small and mountainous with complex rainfall-climate dynamics.

Having said that, the increase in heavy one-day rainfall events aligns with a growing body of scientific evidence on extreme rainfall in a warming world, including in India, and the understanding that a warmer atmosphere holds more moisture, leading to heavier downpours.

According to scientists, the atmosphere’s capacity to hold moisture increases by about 7 per cent for every one-degree Celsius rise in global temperature.

The earth’s global surface temperature has already increased by around 1.3 degrees Celsius due to the rapidly rising concentration of greenhouse gases, primarily Carbon Dioxide and Methane. Scientists say this is the reason behind worsening extreme weather events, such as droughts, heatwaves and floods worldwide.

The WWA scientists said that while the relationship between land cover, land use changes and landslide risk in Wayanad is not fully clear from existing studies, factors, such as quarrying for building materials and a 62 per cent reduction in forest cover may have increased the slopes’ susceptibility to landslides during heavy rainfall.

Other researchers have also linked the Wayanad landslides to a combination of forest cover loss, mining in fragile terrain and prolonged rain followed by heavy precipitation.

S Abhilash, the director of the Advanced Centre for Atmospheric Radar Research at Cochin University of Science and Technology (CUSAT), had earlier told PTI that the warming of the Arabian Sea is leading to the formation of deep cloud systems, resulting in extremely heavy rainfall in Kerala in a short period and increasing the risk of landslides.

“Our research found that the southeast Arabian Sea is becoming warmer, causing the atmosphere above Kerala to become thermodynamically unstable. This instability is allowing the formation of deep clouds,” he had said.

According to the landslide atlas released by ISRO’s National Remote Sensing Centre last year, 10 out of the top 30 landslide-prone districts in India are in Kerala, with Wayanad ranked at the 13th spot.

A study published by Springer in 2021 said all landslide hotspots in Kerala are in the Western Ghats region and are concentrated in Idukki, Ernakulam, Kottayam, Wayanad, Kozhikode and Malappuram districts.

It said about 59 per cent of total landslides in Kerala have occurred in plantation areas.

A 2022 study on depleting forest cover in Wayanad showed that 62 per cent of forests in the district disappeared between 1950 and 2018, while plantation cover rose by around 1,800 per cent.
 

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