Rising concerns grip the scientific community as successive heatwaves cast a shadow over the delicate balance of our natural world, posing a dire threat to the essential role nature plays in furnishing our sustenance. The ominous specter of “unseen, silent dying” looms over the oceans, as the Earth grapples with unprecedented temperatures during these record-breaking times.

The scorching impact of heatwaves is felt across continents, as Europe, the US, and China reel under their searing grasp. July marked a solemn milestone, witnessing the hottest day ever registered globally, thereby imperilling not only human lives but also the terrestrial and aquatic ecosystems that humanity relies upon for survival.

“Our food system is global,” said John Marsham, professor of atmospheric science at the University of Leeds. “There are growing risks of simultaneous major crop losses in different regions in the world, which will really affect food availability and prices. This is not what we’re seeing right now, but in the coming decades that’s one of the things I’m really scared of.

“As a human being, if you’re wealthy enough, you can get inside and put the air conditioning on. But natural ecosystems and farmed ecosystems can’t do that.

Recollections of the 2018 European heatwave are tinged with agricultural despair, with crop failures and yield losses of up to 50% plaguing central and northern Europe. The devastation did not wane, as 2022 bore witness to record temperatures snuffing out fruits and vegetables on British vines.

A grim trajectory looms ahead: projections suggest that heatwaves could surge in frequency by a staggering twelvefold by 2040, juxtaposed against pre-warming standards. While a solitary heatwave might not spell doom for an ecosystem, the compounded effect of prolonged and recurrent events robs nature of the crucial recovery time it demands.

Marsham said: “People are generally isolated from the effects of the weather on which we all depend. We go to shops to buy food – we don’t grow it ourselves. But if you talk to farmers anywhere in the world, they are extremely aware of what the weather is doing, and the impacts on their farming.”

Yet, the climate crisis, with its relentless assault, doesn’t restrict itself to aerial heatwaves; it amplifies the peril beneath the waves as well. Coastal communities confront the surge of oceanic heatwaves, disrupting marine ecosystems—a bedrock resource for sustenance. The grim fallout includes mass mortalities, as seen in the catastrophic 2021 “heat dome” event along Canada’s Pacific coast, where an estimated billion marine creatures perished.

Daniela Schmidt, professor of earth sciences at the University of Bristol, said: “We often think about impacts on ecosystems on land because it’s easy to see – the plants wilt and animals get too hot. But people generally don’t think about marine heatwaves. That’s what really worries me – that unseen, silent dying.”

The vulnerability of ecosystems accustomed to stable year-round temperatures comes into stark relief, particularly for those in tropical oceans. The dire prediction of warming by 2°C signifies the potential obliteration of tropical coral reefs—nurturers of unparalleled biodiversity and pillars of sustenance for over half a billion people, mostly in economically challenged nations.

“I’ve got young kids,” Marsham said. “Whenever you watch Finding Nemo or read a book about coral reefs, you can’t help but feel that, on some level, you’re selling them a lie. Unless we act fast, those systems are going to disappear. Some people might not care about coral reefs, but there’s no part of the globe that is immune to the impacts of climate change.”

Schmidt added: “Not everything has to have a financial value. You need plants for every breath you take. It’s the oxygen you breathe – we tend to forget that.”

The realm of scientific understanding concerning the repercussions of heat on ecosystems is nascent. Research spotlighting a high-emissions scenario, anticipating a 4.4°C surge, paints a grim picture: by 2099, a startling 41% of land vertebrates could confront extreme thermal events. The toll of soaring temperatures manifests as multifaceted maladies, impacting growth, fertility, immunity, and behavioral patterns.

The struggle for survival prompts species to embark on a perilous journey up mountainsides and toward frigid poles, seeking refuge from the escalating heat. Regrettably, this desperate migration heralds an ominous crescendo—more species marching towards the precipice of extinction.

However, within the labyrinth of challenges, glimmers of hope emerge. Nature’s resilience becomes a potent ally in mitigating the ravages of extreme heat. Water bodies, like ponds and fountains, emerge as unsung heroes, fortifying landscapes against scorching summers and arid spells, tempering the menace of wildfires and drought-induced desolation.

Dr Nicole Miranda, a senior researcher at the Oxford Martin programme on the Future of Cooling, said: “The presence of vegetation and water in our landscape can serve as ways to passively cool our surroundings. Trees and plants provide shading and also have the mechanism of evapotranspiration. Bodies of water, such as ponds and fountains, capture the heat around them by evaporating water.”

Illustrative of this potential is the expansive verdant network in Medellín, Colombia, which has purportedly sheared urban heat by a substantial 2°C, offering a testament to nature’s ingenious solutions in the face of escalating adversity.