A driver sleeps inside his auto rickshaw parked in the the shade of a tree as the city continues to be gripped by a heat wave, in New Delhi, India, Tuesday, June 18, 2024. A monthslong heat wave across swathes of India has killed more than 100 people and led to over 40,000 suspected cases of heat stroke in the last three and a half months, a Health Ministry official said Thursday.
| Photo Credit: AP

Months of scorching temperatures sometimes over 50 degrees C in parts of India this year — its worst heat wave in over a decade — left hundreds dead or ill. But the official number of deaths listed in government reports barely scratches the surface of the true toll and that’s affecting future preparations for similar swelters, according to public health experts.

India now has a bit of respite from the intense heat, and a different set of extreme weather problems as monsoon rain lashes the northeast, but for months the extreme heat took a toll on large swaths of the country, particularly in northern India, where government officials reported at least 110 heat-related deaths.

Public health experts say the true number of heat-related deaths is likely in the thousands but because heat is often not listed as a reason on a death certificate many heat deaths don’t get counted in official figures. The worry, they say, is that undercounting the deaths means the heat wave problem isn’t as prioritized as it should be, and officials are missing out on ways to prepare their residents for the scorching temperatures.

All of India’s warmest years on record have been in the last decade. Studies by public health experts found that up to 1,116 people have died every year between 2008 and 2019 due to heat.

As part of his work in public health, Srinath Reddy, the founder of the Public Health Foundation of India, has advised state governments on how to factor in heat when recording deaths.

He found that as a result of “incomplete reporting, delayed reporting and misclassification of deaths,” heat-related deaths are significantly undercounted around the country. Despite national guidelines for recording deaths, many doctors — especially those in overcrowded public hospitals where resources are already strained — don’t follow it, he said.

“Most doctors just record the immediate cause of death and attribution to environmental triggers like heat are not recorded,” Reddy said. That’s because heat deaths can be classified as exertional or non-exertional: Exertional is when a person dies due to direct exposure to high temperatures and non-exertional is when young children, older people or people with pre-existing health conditions become seriously ill or sometimes die from the heat, even if indoors.

“The heatwave is the final straw for the second category of people,” said Dileep Mavalankar, former head of the Indian Institute of Public Health in Gandhinagar. “Most people dying during heat waves belong to this category but their deaths are not recorded as connected to the heat.”

Mavalankar agreed the official number of heat deaths this year is an undercount. He said there were 40,000 recorded case of heat stroke, but only 110 deaths. “This is just 0.3% of the total number of heatstroke cases recorded, but usually heat deaths should be 20 to 30% of heatstroke cases,” he said.

“We need to be counting deaths better,” Mavalankar said. “That is the only way we will know how severe the consequences of extreme heat are.”

In his former role at the Indian Institute of Public Health in Gandhinagar, Gujarat, Mavalankar was instrumental in developing India’s first-ever heat action plan for the city of Ahmedabad in 2013, three years after more than 1,300 people died there during a heat wave.

The heat plan included measures like increasing access to shaded areas for outdoor workers, converting relatively cool public buildings to temporary shelters for people without homes or access to electricity and ensuring hospitals have adequate medical supplies and staff during heat waves.

In the years that followed, Mavalankar and his team studied the impact of the heat plan by counting death tolls in subsequent hot summers. Because of a lack of data on heat deaths specifically, the team looked at deaths from all causes, which spikes during heat waves, and used the number of excess deaths to determine how many deaths were likely caused by heat.

They estimate that the heat action plan had helped reduce the number of fatalities during heat waves by up to 40%.

Having that data, while imperfect, Mavalankar said, allowed the city to adequately prepare itself for extreme heat, and do more of what worked in the future.

But he said the lack of data elsewhere makes it difficult to replicate the results in Ahmedabad on a national level.

“Not reporting these deaths, sharing data, is like the Indian Meteorological Department not sharing weather data,” he said. “We can easily do this across the country but we’ve not decided that we should do it.”

The Indian government collects data on heat-related deaths through the health ministry’s National Centre for Disease Control which is then shared with the National Disaster Management Agency. The agency then shares the data as a total nationwide figure for the year, but a state by state breakdown is not publicly available.

The National Crime Records Bureau also collects heat-related death data as part of their accounting of deaths due to “forces of nature” and publishes those figures.

But there are huge discrepancies. In 2020, the last year with publicly available data on heat deaths from both official sources, the crime records bureau recorded 530 deaths from heatstroke, but the disaster agency reported just four heat-related deaths.

The Associated Press contacted India’s health ministry spokesperson, the NCDC and the NDMA to comment on the discrepancy but did not receive a response.

Getting better data can answer a whole host of questions about who is most vulnerable and how best to help them, said Bharghav Krishna, a public health expert and a fellow at the Sustainable Futures Collaborative thinktank, “especially with respect to identifying who is dying, where they’re dying, what are they doing when they’re dying.”

Krishna thinks that the data currently collected, while inadequate, can at least provide some insight for policymakers and researchers and force at least some action if its shared with the right people.

But Malavankar said the issues of data collection are more systemic, and that needs to be urgently addressed.

“We have not done a national census since 2011, not having numbers is our national weakness,” he said.

A general view of installed solar panels at the Khavda Renewable Energy Park of Adani Green Energy Ltd (AGEL), in Khavda, India, April 12, 2024.
| Photo Credit: Reuters

With just five months to go before this year’s U.N. climate summit, countries cannot agree on the size of a global funding bill to help the developing world fight climate change – let alone how to split it.

The decision is set to dominate the COP29 climate talks in Azerbaijan in November, where nearly 200 countries need to agree on a new annual financing target for helping poorer countries cut their emissions and protect their societies in a harsher, hotter world.

The new target will replace the yearly $100 billion that rich countries had pledged in climate finance from 2020. That goal was met two years late.

But preliminary talks this week in Bonn, Germany, have yielded no major breakthroughs. Instead, the talks ending on Thursday have again exposed the unyielding rifts among the world’s biggest economies over who should be paying most to fight climate change – and how much.

Representatives from climate-vulnerable nations said it was hard watching wealthy nations fall late with past payments of climate finance while quickly approving new funds for military responses to war or spending billions subsidising CO2-emitting energy sources.

“It seems like money is always there when it’s a more ‘real’ national priority for the country,” Michai Robertson, negotiator for the Alliance of Small Island States, told Reuters.

“It’s really tough to see that,” he said.

Getting the number right

The new financing target is the core tool that global climate talks can deliver to fund projects that reduce planet-warming emissions – such as renewable energy or low-carbon transport.

With all countries due to update their national climate targets next year, negotiators fear failure could lead to weaker efforts.

“How are you going to move forward if there’s no financing?” said South African climate negotiator Pemy Gasela. Her country is among many developing nations warning they cannot afford to cut emissions faster without more financial support – in South Africa’s case, to swap a heavy reliance on CO2-emitting coal for clean energy.

Yet wealthy countries are wary of setting a target too high and risking it going unmet. The missed $100 billion target became politically symbolic in recent U.N. climate talks, stoking mistrust between nations as developing countries argued the world’s economic powers were abandoning them.

Diplomats in Bonn have circled the issue of how much money to put on the table.

While countries agree $100 billion is too low, there is little chance they would agree to summon the $2.4 trillion per year that the U.N. climate chief in February said was needed to keep the world’s climate goals within reach.

Neither the European Union or the U.S. have suggested a number for the goal, although both acknowledged this week that it must exceed $100 billion. The 27-country EU is currently the biggest provider of climate finance.

The elephant in the negotiation rooms, some diplomats told Reuters, was the upcoming U.S. presidential election, in which Donald Trump is seeking to return to office.

The previous Trump administration pulled the world’s biggest economy out of the Paris climate agreement. Negotiators said they worry a future Trump administration could halt U.S. climate finance payments, leaving it to other wealthy nations to meet the annual pledge.

But some countries in Bonn have made suggestions.

India, and a group of Arab countries including Saudi Arabia, the UAE and Egypt, have said the overall financing target should exceed $1 trillion per year, to reflect the spiralling needs of poorer countries as climate change worsens.

The Arab countries propose that rich nations provide $441 billion in public funding per year in grants, to leverage a total $1.1 trillion per year from broader sources.

Small island countries vulnerable to climate change have also pushed for stricter rules on what counts toward the target, suggesting preventing loans with interest rates above 1%, to avoid adding to poor nations’ already-high debts.

Most public climate funds provided by developed nations are loans, according to the OECD.

Deciding who should pay

Countries are also at odds over who should contribute.

There are about two dozen, long-industrialized countries currently obliged to contribute to U.N. climate finance. That list was decided during U.N. climate talks in 1992, when China’s economy was still smaller than Italy’s.

The EU wants China – now the world’s biggest CO2 emitter and second biggest economy – and high wealth-per-capita Middle Eastern countries to contribute for the new goal. The U.S. has also argued for adding more countries in the donor base.

However, the Arab countries and China firmly opposed this idea, with Beijing reiterating China’s status as a “developing country” under the U.N. climate convention.

“We, the developing countries, have no intention to make your number look good or be part of your responsibility, as we are doing all we can do to save the world,” China’s negotiator told other diplomats during negotiations on the finance target in Bonn on Tuesday.

Neither camp of countries has compromised on who should pay, said Joe Thwaites, who tracks climate finance negotiations for the non-profit Natural Resources Defense Council.

“Negotiations were difficult and things are moving slowly,” he said.

As talks continue beyond Bonn, some negotiators said government ministers could raise the issue at higher level meetings such as G20 ministers’ gatherings in Brazil ahead of COP29.

Bleached coral is visible at the Flower Garden Banks National Marine Sanctuary, off the coast of Galveston, Texas, in the Gulf of Mexico, September 16, 2023. Ocean temperatures that have gone “crazy haywire” hot, especially in the Atlantic, are close to making the current global coral bleaching event the worst in history. It’s so bad that scientists are hoping for a few hurricanes to cool things off.
| Photo Credit: AP

Nearly two-thirds of the world’s coral reefs have been subjected to heat stress bad enough to trigger bleaching over the past year, the leading agency monitoring coral reefs said on Thursday.

The U.S. National Oceanic and Atmospheric Administration (NOAA) announced last month that the world’s coral reefs were in the throes of a fourth mass bleaching event, as climate change combined with an El Nino climate pattern has pushed ocean temperatures to record highs.

Now, the agency reports some 60.5% of the world’s reef area has been affected and that number is still rising.

“I am very worried about the state of the world’s coral reefs,” NOAA’s Coral Reef Watch coordinator Derek Manzello said in a monthly briefing. “We are seeing (ocean temperatures) play out right now that are very extreme in nature”.

Triggered by heat stress, coral bleaching occurs when corals expel the colourful algae living in their tissues. Without these helpful algae, the corals become pale and are vulnerable to starvation and disease.

Scientists have documented mass bleaching in at least 62 countries and territories, with India and Sri Lanka recently reporting impacts.

The last global event, which ran from 2014 to 2017, saw 56.1% of reef areas subjected to bleaching-level heat stress. Previous events in 1998 and 2010 hit 20% and 35% of reef area, respectively.

While the current event has affected a greater swath, Manzello said the 2014-17 event is still considered the worst on record due its severity and persistence. But 2023-24 could soon surpass it, he added.

Caribbean corals at risk

Corals in the Atlantic Ocean have been hit hardest by soaring ocean temperatures, with 99.7% of the basin’s reefs subjected to bleaching-level heat stress in the past year, NOAA said.

“The Atlantic Ocean has been off the charts,” Manzello said.

One assessment published in April 2024 found there had so far been between 50% and 93% coral mortality at Huatulco, Oaxaca, in the Mexican Pacific.

The situation is likely to worsen this summer, as heat stress is once again accumulating in the Southern Caribbean. In some areas, the heat stress threshold for bleaching to occur has already been passed.

“This is alarming because this has never happened so early in the year before,” Manzello said.

Scientists are expecting further bleaching in the Southern Caribbean, around Florida, and at the Mesoamerican Barrier Reef – the world’s second largest reef – this summer.

“El Nino is dissipating, but the ocean is still anomalously hot. It won’t take much additional warming to push temperatures past the bleaching threshold,” he said.

Representational image of man standing on top of a skyscraper view of the Bangkok city skyline.
| Photo Credit: Getty Images

Thailand may have to consider relocating its capital Bangkok because of rising sea levels, a senior official in the country’s climate change office said on May 15.

Projections consistently show that low-lying Bangkok risks being inundated by the ocean before the end of the century.

Pavich Kesavawong, Deputy Director-general of the Government’s department of climate change and environment, warned that the city might not be able to adapt with the world on its current warming pathway.

“I think we are beyond the 1.5 (C) already,” he said, referring to the increase in global temperatures from pre-industrial levels.

“I imagine Bangkok will be under water already, if we stay in our (current) circumstance.”

Bangkok’s city Government is exploring measures that include building dikes, along the lines of those used in the Netherlands, he said.

But “we have been thinking about moving”, Mr. Pavich said, noting that the discussions were still hypothetical and the issue was “very complex”.

“Personally I think it’s a good choice, so we can separate the capital, the Government areas, and business areas,” he said.

“Bangkok (would) still be the Government capital, but move the business.”

While a move is still a long way from being adopted as policy, it would not be unprecedented in the region.

Indonesia will inaugurate this year its new capital Nusantara, which will replace sinking and polluted Jakarta as the country’s political centre.

The mercury is soaring across India, with many places reporting unusually high temperature readings. It may not be possible to link each heat event to climate change, but we know climate change is bringing such anomalies to more areas, and with greater intensity.

We also know climate change is disproportionately affecting society’s most vulnerable members, including those with physical ailments, the elderly, the poor, and the socially and economically marginalised. And we also know climate change has become the basis of a slew of psychological afflictions of its own, including eco-anxiety, eco-paralysis, and solastalgia (a form of emotional or existential distress rendered by environmental changes), together with seeding general concerns in communities worldwide about their livelihoods, future, the future of their children, and their culture.

But let’s not forget that climate change’s multi-dimensional assault on reality as we know it also potentially includes being able to worsen existing mental health conditions.

A dubious distinction

A study published in 2023 in the journal GeoHealth reported that an extreme heat event in the Canadian province of British Columbia in 2021 affected people with schizophrenia more than those with kidney and heart disease. The study’s authors, of the British Columbia Centres for Disease Control and Health Canada, also wrote that people with mental health conditions seem to be at a greater risk of succumbing to heat-related deaths. The stakes were found to be even higher for people diagnosed with schizophrenia, anxiety or bipolar disorder.

During the eight-day extreme heat event in 2021, the province of British Columbia experienced temperatures as high as 40 degrees C when the average temperatures have been around 20 degrees C. The region recorded around 740 excess deaths during this heat wave.

To understand who was affected the most during this event, the researchers compared 1,614 deaths recorded over a month in 2021 with 6,524 deaths recorded in the same time period nine years ago. They analysed the data based on 26 medical conditions, including heart disease, schizophrenia, chronic kidney disease, dementia, depression, Parkinson’s disease, and osteoporosis.

The scientists wrote that they expected to find people with kidney and heart diseases to be most at risk, but were surprised to find that that dubious distinction belonged to people with schizophrenia. In particularly, they reported that 8% of the people surveyed in 2021 were previously diagnosed with schizophrenia as opposed to 2.7% of the people surveyed nine years ago. This was a 200% increase from a summer in which heat waves weren’t recorded.

To be sure, while people with schizophrenia were found to be at greater risk of heat-related distress than those with kidney and heart diseases, the latter weren’t immune: they were at risk as well, just less so.

Dysfunction of the hypothalamus

A closer look at the data revealed that of the 280 people whose deaths were confirmed to be related to heat, 37 people had schizophrenia. “These results show that people with schizophrenia need extra protection, extra support and extra care,” Sarah Henderson, one of the epidemiologists who led the study and the scientific director of Environmental Health Services at the British Columbia Centre for Disease Control, told Science.

The researchers believe one of the main reasons people with schizophrenia were more vulnerable to heat stress could be as a result of the dysfunction of the hypothalamus, a structure embedded deep in the human brain. Its main function is to maintain the homeostasis of the body, i.e. to keep the body in a stable condition that ensures it can carry out its normal function. This means it controls of the body’s temperature, heart rate, hunger, thirst, mood, libido, sleep, and the regulation of hormones.

Certain antipsychotic medications prescribed to people with schizophrenia have also been found to interfere with the hypothalamus’s workings. One side-effects of such drugs has been a tendency to raise the body’s temperature, which when coupled with anomalously high ambient temperatures can rapidly prove fatal.

People with schizophrenia also often have psychotic symptoms such as hallucinations, delusions, disorganised thinking, and memory loss. They may also suffer from anosognosia: a condition in which they’re unable to sense that they’re ill. All this together with comorbidities like diabetes and hypertension can make life very difficult for people with schizophrenia, including potentially interfere with their ability to seek help.

As it happens, marginalisation, lower economic status, and a propensity for loneliness are risk factors for people with schizophrenia, and the same factors can heighten an individual’s vulnerability to heat-related illnesses, as the infamous 1995 Chicago heat event demonstrated.

Yet another tentacle

But for some antipsychotic medicines’ potential to interfere with people’s experience of anomalous ambient heat, scientists have cautioned that they shouldn’t be discontinued or tampered with because these are ‘lifesaving therapies’. They have suggested that the risk factors associated with schizophrenia, including social isolation, should be tackled instead with interventions like counselling and checking in on them regularly.

In a statement issued by the British Columbia Centres for Disease Control, Faydra Aldridge, CEO of the British Columbia Schizophrenia Society, said, “As demonstrated by the recent research, because individuals living with schizophrenia are more susceptible to heat-related illness, it is essential that families and caregivers are aware of the increased risk, identify potential risk factors and take prompt action to help their loved one during a heat wave.”

She added that “educating ourselves to recognise symptoms of heat-related illness and take emergency cooling measures will help ensure everyone’s safety during heat waves.”

One of the defining characteristics of climate change is the nonlinear nature of its effects, i.e. their ability to compound rapidly, affecting several walks of human life both directly and indirectly. The GeoHealth study elucidated one more example of this ability, adding to previous work that has examined its influence on everything from domestic violence to child-trafficking.

Australia’s famed Great Barrier Reef is suffering one of the most severe coral bleaching events on record, leaving scientists fearful for its survival as the impact of climate change worsens.

For 33 years marine biologist Anne Hoggett has lived and worked on Lizard Island, a small slice of tropical paradise off Australia’s northeast tip.

She affectionally dubs it “Blizzard Island”. The only relief from the wind and teeming showers is in the powder blue waters, where sea turtles and tiger sharks rove along the Great Barrier Reef.

As Hoggett snorkels, schools of fish swim gracefully, feeding on the coral or darting between it. Some are as small as her little finger, others the colour of fire.

But thanks to climate change, it is becoming a watery graveyard of bleached reef.

“We don’t know yet if they’ve already sustained too much damage to recover or not,” said Hoggett.

The world is currently experiencing its second major coral bleaching event in 10 years, the US National Oceanic and Atmospheric Administration (NOAA) announced Monday.

Coral bleaching occurs when water temperatures rise more than one degree Celsius (33.8 degrees Fahrenheit).

“As the world’s oceans continue to warm, coral bleaching is becoming more frequent and severe,” said NOAA’s Derek Manzello.

In a bid to survive, the coral expels microscopic algae, known as zooxanthellae, which it needs to live.

If high temperatures persist, the coral eventually evicts most of the zooxanthellae, turns white, and dies.

Since February, ocean temperatures around Lizard Island have been up to two degrees Celsius warmer than the average.

Hoggett estimates about 80% of the coral is already dead.

Just about everything died

Often dubbed the world’s largest living structure, the Great Barrier Reef is a 2,300-kilometre (1,400-mile) long expanse housing a stunning array of biodiversity, including more than 600 types of coral and 1,625 fish species.

It is vital to the health of the ocean and Australia’s tourism industry, netting billions of dollars every year.

But repeated mass bleaching events have robbed the reef of its wonder, turning banks of once-vibrant corals to a sickly ashen white.

In March, Australian reef authorities announced another mass bleaching event was underway, the fifth in eight years.

Through aerial monitoring, they found more than 600 reefs have experienced bleaching.

Ten per cent of the area is classed as suffering extreme bleaching, when more than 90% of corals are distressed and unlikely to survive.

Just nine weeks ago, the reef off Lizard Island was healthy and vibrant, Hoggett said.

Now, she points to the fluorescent pink and blue coral. Despite its initial beauty, that means the coral is highly stressed and expelling the healthy algae it needs to survive.

Elsewhere, white coral is covered in a fluffy, brown algae — a sign it is dead.

When Hoggett first arrived on the island three decades ago, bleaching would occur every 10 years or so. Now, it is happening every year.

Mass bleaching events along the reef occurred in 1998, 2002, 2016, 2017, 2020, 2022 and now 2024.

She is heartbroken.

“The only time we’ve seen bleaching this bad was in 2016, when just about everything died,” Hoggett told AFP.

“It’s anybody’s guess as to how many of these corals that are still alive now will be able to survive and recover.”

Too small in scale

While reefs can recover from bleaching, the window of recovery between events is narrowing.

As the planet continues to warm, bleaching is forecast to reduce global coral cover by 95% if temperatures warm by about two degrees.

If the rise is up to 1.5 degrees above pre-industrial levels, bleaching will spread to 70%.

Even if all countries deliver on their climate commitments, the world would still be on track for two degrees or more of warming.

Globally, billions of dollars are being poured into coral bleaching mitigation projects — including breeding coral on artificial reefs and translocating it, making clouds more heat reflective, or controlling coral predators.

These site-specific conservation efforts are important, but Terry Hughes, one of Australia’s foremost coral reef scientists, says they do nothing to address the root cause of bleaching: climate change.

“After 50 years of interventions, coral restoration attempts have not changed the ecology of a single reef anywhere,” Hughes said. “They’re just too small in scale.”

For example, Hughes says breeding corals in aquariums has strict limitations.

“You would need 250 million large corals, each the size of a dinner plate, to increase coral cover in the Great Barrier Reef by just one per cent — and it would cost billions of dollars,” he added.

“The solution is to reduce greenhouse gas emissions as quickly as possible.”

Not giving up

Australia has invested about Aus$5 billion ($3.2 billion) into improving water quality, reducing the effects of climate change, and protecting threatened species.

The country is one of the world’s largest gas and coal exporters, and has only recently set loose targets to become carbon neutral.

Whether these efforts will be enough to see the reef keep its World Heritage Status will be examined by UNESCO later this year.

Great Barrier Reef Marine Park Authority chief scientist Roger Beeden says it will take some time before the full extent of this year’s event are realised, but he is hopeful coral will recover.

“There’s hundreds of species of corals, they have evolved in an environment that is incredibly dynamic. They are very adaptable,” he said.

“We need to do all that we can. I’m always hopeful. I think like medical doctors — I’m not giving up on this patient.”

On Lizard Island, Hoggett worries for its future.

“Coral reefs are so beautiful, and I love them so much. They do so much good for the world,” she said.

“It just makes me angry that it’s within our power to stop this from happening and we are not doing anything quickly enough.”

The effects of ocean warming are profound and well-documented. But sometimes changes in the patterns of winds and ocean currents cause seawater to suddenly cool, instead.

Surface temperatures can plummet rapidly — by 10ºC or more over a day or two. When these conditions persist for several days or weeks, the area experiences a “coldwave”, which is the opposite of more familiar marine heatwaves.

When a “killer coldwave” manifested along South Africa’s southeast coast in March 2021, it killed hundreds of animals across at least 81 species. More worrying still was the fact these deaths included vulnerable manta rays and even specimens of notoriously robust migratory bull sharks. In southern Africa, bull sharks, whale sharks and manta rays have previously washed up dead following such sudden cold events, especially over the past 15 years.

As we report in Nature Climate Change, the conditions that can drive these killer coldwaves have grown increasingly common over the past four decades. Ironically, strengthening winds and currents as a result of climate change can also make these deadly localised coldwaves more likely in places such as the east coasts of South Africa and Australia, potentially putting even highly mobile species such as sharks in harm’s way.

What’s going on?

Certain wind and current conditions can cause the sea surface to cool, rather than warm. This happens when winds and currents force coastal waters to move offshore, which are then replaced from below by cold water from the deep ocean. This process is known as upwelling.

In some places, such as California on the US west coast, upwelling happens regularly along hundreds of kilometres of coastline. But localised upwelling can occur seasonally on a smaller scale, too, often at the edges of bays on the east coasts of continents due to interactions of wind, current and coastline.

Previous research had shown climate change induced changes in global wind and current patterns. So we investigated the potential consequences at particular locations, by analysing long-term wind and temperature data along the south-eastern coast of South Africa and the Australian east coast.

This revealed an increasing trend in the number of annual upwelling events over the past 40 years. We also found an increase in the intensity of such upwelling events and the extent to which temperatures dropped on the first day of each event – in other words, how severe and sudden these cold snaps were.

Mass deaths warrant investigation

During the extreme upwelling event along the southeast coast of South Africa in March 2021, at least 260 animals from 81 species died. These included tropical fish, sharks and rays.

To investigate the ramifications for marine fauna, we took a closer look at bull sharks. We tagged sharks with tracking devices that also record depth and temperature.

Bull sharks are a highly migratory, tropical species that only tend to travel to upwelling regions during the warmer months. With the onset of winter, they migrate back to warm, tropical waters.

Being mobile, they should have been able to avoid the local, cold temperatures. So why were bull sharks among the dead in this extreme upwelling event?

When running and hiding isn’t enough

Bull sharks survive environmental conditions that would kill most other marine life. For example, they’re often found several hundred kilometres up rivers, where other marine life would not venture.

Our shark tracking data from both South Africa and Australia showed bull sharks actively avoid areas of upwelling during their seasonal migrations up and down the coast, even when upwelling isn’t too intense. Some sharks take shelter in warm, shallow bays until the water warms again. Others stick close to the surface where the water is warmest, and swim as fast as they can to get out of the upwelling.

But if marine coldwaves continue to become more sudden and intense, fleeing or hiding may no longer be enough even for these tough beasts. For example, in the event in South Africa that caused the death of manta rays and bull sharks water temperatures dropped from 21°C to 11.8°C in under 24 hours while the overall event lasted seven days.

This sudden, severe drop paired with the long duration made this event particularly deadly. If future events will continue to become more severe, mass deaths of marine life could become a more common sight – especially along the world’s mid-latitude east coasts.

Still learning how climate change will play out

Overall, our oceans are warming. The ranges of tropical and subtropical species are extending towards the poles. But along some major current systems, sudden short-term cooling can make life difficult for these climate migrants, or even kill them. Especially if events like the one in South Africa become more common. Tropical migrants would increasingly be living on the edge of what they are comfortable with in these areas.

Our work emphasises that climate impacts can be unexpected or even counterintuitive. Even the most resilient life forms can be vulnerable to its effects. While we do see an overall warming, changes in weather and current patterns can cause extreme cold events as well.

This really shows the complexity of climate change, as tropical species would expand into higher-latitude areas as overall warming continues, which then places them at risk of exposure to sudden extreme cold events. In this way, species such as bull sharks and whale sharks may very well be running the gauntlet on their seasonal migrations.

The need to limit our impacts on the planet by reducing greenhouse-gas emissions has never been more urgent, nor has been the need for research into what our future might hold.

Rosmarie Wydler-Walti and Anne Mahrer, of the Swiss elderly women group Senior Women for Climate Protection, attend the hearing of the court for the ruling in the climate case Verein KlimaSeniorinnen Schweiz and Others v. Switzerland, at the European Court of Human Rights (ECHR) in Strasbourg, France April 9, 2024.
| Photo Credit: Reuters

Switzerland for all its snow-capped mountains and crisp Alpine air has failed to protect its people from the ravages of climate change, as a top European court ruled this week.

Behind the picture postcard exterior, critics say, is a country that has done too little for the planet and acted as a business hub for some of the most powerful international corporations in fossil fuels and mining.

Political analysts and academics also say entrenched conservatism and a political system governed by popular referendums will complicate reform even after Tuesday’s ruling by the European Court of Human Rights in Strasbourg.

It found in favour of over 2,000 Swiss women – a third of them over 75 – who said their country’s inaction in the face of rising temperatures puts them at risk of dying during heatwaves.

The ruling cannot be appealed and the Swiss Federal Office of Justice, which represented the government before the court, said it must be implemented. It said it would analyse the ruling to determine the measures the country needed to take.

Immediately after the court decision, the Swiss Green Party called for climate targets for specific industries, including the finanical sector.

“People may have slightly beautiful dreams about Switzerland,” Lisa Mazzone, the party leader, said.

“Switzerland is the country of commodity trading, Switzerland is the country with a strong financial sector with a lot of investment in fossil fuels,” she added.

Swiss-based commodity trading companies handle 40% of all oil trades and 60% of the metal trading business, according to data published by industry association Suissenégoce.

The group of Swiss women known as KlimaSeniorinnen did not make Swiss trading central to their case, although their Greenpeace-backed campaign that lasted many years called for tougher regulation to curb transactions fueling global warming.

Referendums

A 2022 international study into environmental sustainability ranked Switzerland in the top 10, but government efforts to implement stricter climate goals have so far been limited by the country’s regular referendums.

Leading Swiss newspapers took a sceptical view of the ruling in editorials that said it could undermine democracy.

The largest party, the right-wing Swiss People’s Party, said Switzerland should withdraw from the Council of Europe, which seeks to promote human rights in Europe and beyond, calling the court’s judges “puppets for activists”.

Unlike most western democracies where central governments drive political change, Switzerland is governed by a cross-party consensus balancing the interests of its 26 cantons.

Dilara Bayrak, a Green politician in Geneva, said the ruling should still energise climate debate in cantonal parliaments.

Financial muscle and tons of carbon

The ruling is also likely to sharpen environmental campaigners’ focus on how Switzerland’s serves global industry through its network of traders and banks.

The financial sector, including the central bank, is already under pressure from environmental groups to curb the number of climate-damaging transactions it processes.

Data published last month by the Swiss National Bank (SNB) showed that its investments were linked to 12 million metric tons of carbon emissions in 2023.

Stakes in oil majors Chevron Corp and Exxon Mobil are part of its foreign reserves, which stood at 655 billion Swiss francs ($738.28 billion) at the end of 2023.

The SNB said it is reducing its own CO2 emissions, but would not change its investment policy. It declined to comment when asked whether the Strasbourg court ruling would lead to changes.

The actions the ruling say Switzerland must carry out include revising its 2030 emissions reductions targets to align them with the Paris Agreement’s aim to limit warming to 1.5 Celsius (2.7 Fahrenheit) above pre-industrial levels.

It also determined that Switzerland had not complied with its own targets for cutting greenhouse gas emissions and had failed to set a national carbon budget.

But the country’s deep-rooted tradition of referendums is likely to make reform a slow process.

“It’s not going to happen overnight,” said Pascal Mahon, a professor of constitutional law at the University of Neuchâtel.

“Switzerland is a country that respects international law rather well,” he added. “Authorities will make sure to (respect) it, but by doing it through the Swiss political system, that’s still relatively slow and conservative.”

A soldier works to contain wildfires in Nogales, in the High Mountains area of Veracruz state, Mexico, Monday, March 25, 2024.
| Photo Credit: AP

In the U.S., wildland firefighters are able to stop about 98% of all wildfires before the fires have burned even 100 acres. That may seem comforting, but decades of quickly suppressing fires has had unintended consequences.

Fires are a natural part of many landscapes globally. When forests aren’t allowed to burn, they become more dense, and dead branches, leaves and other biomass accumulate, leaving more fuel for the next fire. This buildup leads to more extreme fires that are even harder to put out. That’s why land managers set controlled burns and thin forests to clear out the undergrowth.

However, fuel accumulation isn’t the only consequence of fire suppression.

Fire suppression also disproportionately reduces certain types of fire. In a new study, my colleagues and I show how this effect, known as the suppression bias, compounds the impacts of fuel accumulation and climate change.

What happened to all the low-intensity fires?

Most wildfires are low-intensity. They ignite when conditions aren’t too dry or windy, and they can often be quickly extinguished.

The 2% of fires that escape suppression are those that are more extreme and much harder to fight. They account for about 98% of the burned area in a typical year.

In other words, trying to put out all wildfires doesn’t reduce the total amount of fire equally – instead, it limits low-intensity fires while extreme fires still burn. This effect is worsened by climate change.

Too much suppression makes fires more severe

In our study, we used a fire modeling simulation to explore the effects of the fire suppression bias and see how they compared to the effects of global warming and fuel accumulation alone.

Fuel accumulation and global warming both inherently make fires more severe. But over thousands of simulated fires, we found that allowing forests to burn only under the very worst conditions increased fire severity by the same amount as more than a century’s worth of fuel accumulation or 21st-century climate change.

The suppression bias also changes the way plants and animals interact with fire.

By removing low-intensity fires, humans may be changing the course of evolution. Without exposure to low-intensity fires, species can lose traits crucial for surviving and recovering from such events.

After extreme fires, landscapes have fewer seed sources and less shade. New seedlings have a harder time becoming established, and for those that do, the hotter and drier conditions reduce their chance of survival.

In contrast, low-intensity fires free up space and resources for new growth, while still retaining living trees and other biological legacies that support seedlings in their vulnerable initial years.

By quickly putting out low-intensity fires and allowing only extreme fires to burn, conventional suppression reduces the opportunities for climate-adapted plants to establish and help ecosystems adjust to changes like global warming.

Suppression makes burned area increase faster

As the climate becomes hotter and drier, more area is burning in wildfires. If suppression removes fire, it should help slow this increase, right?

In fact, we found it does just the opposite.

We found that while conventional suppression led to less total area burning, the yearly burned area increased more than three times faster under conventional suppression than under less aggressive suppression efforts. The amount of area burned doubled every 14 years with conventional fire suppression under simulated climate change, instead of every 44 years when low- and moderate-intensity fires were allowed to burn. That raises concerns for how quickly people and ecosystems will have to adapt to extreme fires in the future.

The fact that the amount of area burned is increasing is undoubtedly driven by climate change. But our study shows that the rate of this increase may also be a result of conventional fire management.

The near total suppression of fires over the last century means that even a little additional fire in a more fire-prone future can create big changes. As climate change continues to fuel more fires, the relative increase in area burned will be much bigger.

This puts more stress on communities as they adapt to increased extreme wildfires, from dealing with more wildfire smoke to even changing where people can live.

A way forward

To address the wildfire crisis, fire managers can be less aggressive in suppressing low- and moderate-intensity fires when it is safe to do so. They can also increase the use of prescribed fire and cultural burning to clear away brush and other fuel for fires.

These low-intensity fires will not only reduce the risk of future extreme fires, but they also will create conditions that favor the establishment of species better suited to the changing climate, thereby helping ecosystems adapt to global warming.

Coexisting with wildfire requires developing technologies and approaches that enable the safe management of wildfires under moderate burning conditions. Our study shows that this may be just as necessary as other interventions, such as reducing the number of fires unintentionally started by human activities and mitigating climate change.

Jacaranda tree blooms in the Condesa neighborhood in Mexico City, Mexico. February 22, 2024.
| Photo Credit: Reuters

Every spring, the streets of Mexico’s capital are painted purple with the flowering of thousands of jacaranda trees. Their spectacular colours not only attract the eyes of residents and tourists but also birds, bees and butterflies that find food and shelter in them.

But this year something changed.

Some jacarandas began blooming in early January when they normally awaken in spring. The early onset bloom has set off alarm bells among residents and scientists in Mexico City, where the trees have become an iconic, photogenic mainstay of city streets.

Local scientists have begun investigating how widespread the early-bloom phenomenon is, but they point to climate change as the first culprit.

“We’ve always seen the jacaranda beginning to bloom towards the end of March, in spring, when we see the flowers change to violet,” said Constantino Gonzalez, a researcher at the Institute of Atmospheric Sciences and Climate Change Research at the National Autonomous University of Mexico (UNAM).

“They are starting to flower in January, February, which is winter, when it is not yet their time,” said the biologist of 48 years.

Gonzalez explained that in order to draw a correlation between climate change and the early flowering of jacarandas his team needs a representative sample and compare blooms year to year. To do this, he has started to lead a group of young people who are collecting data throughout the city and using satellite imagery.

He noted rising temperatures caused winter in the Mexican capital to end early this year, in mid-January, instead of late March when it is supposed to end.

Adaptation

Enthralled by the Japanese cherry trees that cover Washington, D.C. in pink and white every spring, Mexican President Pascual Ortiz (1930-1932) set out to replicate the same landscape in his nation’s capital.

But Tatsugoro Matsumoto, a Japanese landscape architect who settled in Mexico in the late 19th century, told him they would not survive the city’s temperate climate for long, so he advocated for jacarandas, a tropical tree he had learnt about during a brief stay in Peru.

Since then, the tree has become a staple for Mexico City’s nine million inhabitants.

In January alarm spread when users on social networks started to publish photos of flowering jacarandas and began to wonder about the effects of climate change.

“Like never before (…) people have started to say ‘this is serious, it’s real’ and it’s no longer just a polar bear floating adrift’,” said Cristina Ayala, biologist and doctor in Sustainability Sciences.

“It is very good that people are beginning to become aware of what climate change is going to bring to us as urbanites,” she added.

Although they are not native to Mexico, for Ayala, jacarandas fulfill an important function for the city. They attract more hummingbirds and bees than many native trees, so a change in flowering could lead to a decrease in these populations.

“One would like the jacarandas to bloom all year round, they brighten the city,” said Alex Estrada, a resident of the Mexican capital, while observing a tree that was beginning to turn purple. “But something is not right here: jacarandas in winter?” he wondered.