‘Climate change a risk to health’

CLIMATE change is set to become the “defining narrative of human health”, a top medical journal warned this week – triggering food shortages, deadly disasters and disease outbreaks that would dwarf the toll of Covid-19. But aggressive efforts to curb greenhouse gas emissions from human activities could avert millions of unnecessary deaths, say more than 100 doctors and health experts.

In its annual “Countdown on health and climate change”, The Lancet shows that more than a dozen measures of humanity’s exposure to health-threatening weather extremes have climbed since last year’s report.

“Humanity faces a crucial turning point,” the doctors say, with nations poised to spend trillions of dollars on economic recovery from the pandemic and world leaders set to meet in Glasgow for a major UN climate conference in less than two weeks.

Rising temperatures have led to higher rates of heat illness, causing farmworkers to collapse in fields and elderly people to die in their apartments. Insects carrying tropical diseases have multiplied and spread toward the poles.

The amount of plant pollen in the air is increasing, worsening asthma and other respiratory conditions. Extreme floods and catastrophic storms have boosted the risk of cholera and other waterborne diseases. Smoke from fires in California infiltrates the lungs and then the bloodstreams of people as far away as Texas, Ohio and New York. Droughts intensify, crops fail, hunger stalks millions of the world’s most vulnerable people.

The Lancet study is just the latest salvo from health professionals demanding a swift end to burning fossil fuels and other planet-warming activities. Dozens of public health experts are headed to the UN climate summit starting at the end of the month, aiming to convince world leaders that they must take bolder action to curb their nations’ carbon output. Yet just half of countries surveyed

said they have a national climate and health strategy in place, the study said. Trends in renewable energy generation and adaptation initiatives have improved only slightly. Most of the world’s biggest emitters still subsidise fossil fuels at rates of tens of billions of dollars per year, rivalling the amounts they spend on public health.

The outcomes of national spending debates and international climate negotiations will either “lock humanity into an increasingly extreme and unpredictable environment”, the report says, or “deliver a future of improved health, reduced inequity, and economic and environmental sustainability”.

The world has not committed yet to cutting emissions enough to avert the worst effects of warming. Based on countries’ current pledges under the Paris climate accord, average temperatures are on track to increase by

a catastrophic 2.7°C by the end of the century. The planet has already warmed about 1.2°C since the preindustrial era. And a UN report this week said G20 countries have directed more new funding to fossil fuels than clean energy since the start of the pandemic.

“A carbon-intensive Covid-19 recovery would irreversibly prevent the world from meeting climate commitments,” the report warns.

The death toll from climate change will outstrip that of Covid-19, warned the scientists, unless drastic action is taken to avert further warming and adapt to changes under way. Just 0.3% of global climate change adaptation funding has been directed at health systems, the report says, despite an explosion of evidence for the health consequences of unchecked emissions. In the past month, studies in academic journals have reported the following:

El Niño weather patterns, which

are projected to intensify as the planet warms, cause about 6 million children to go hungry. The warming of the Amazon, combined with deforestation, will expose about 11 million people to potentially lethal heat by the end of the century.

These new studies have been accentuated by recent climate-linked disasters. Drought in Madagascar has pushed more than 1million people to the brink of starvation. Flash floods in Niger worsened the West African nation’s cholera epidemic.

By far the deadliest hazard comes from burning fossil fuels, which generate lung-irritating particles known as PM2.5. One estimate put the toll of this pollution at more than 10million excess deaths each year.

Elderly people and infants younger than one are exposed to four more extremely hot days per year now than a generation ago, The Lancet report found. Almost 350000 people died of heat-related illness in 2019.

Steadily rising temperatures, habitat disruption and globalisation have also given infectious diseases a chance to evolve and expand. Fungal illnesses, which can’t be treated with vaccines or antibiotics, may be on the rise.

Historically, there haven’t been many fungi capable of infecting humans, because the microbes don’t thrive at typical body temperatures. But as global warming increases the average temperatures in the environments where fungi live, it may be pressuring these species to adapt. This in turn could make them better suited for invading human guts or respiratory tracts, scientists suggest.

Meanwhile, disease-carrying mosquitoes are moving to more temperate areas and higher elevations. Shifting environmental factors have raised the basic reproductive rates of illnesses like Zika and chikungunya, enhancing their potential to explode into epidemics. A study published by the Lancet Planetary Health this July found that unabated carbon emissions would put almost 90% of the world’s population at risk of malaria and dengue by the end of the century.

The diseases will continue to hit hardest in the low-lying, tropical nations in sub-Saharan Africa, and the toll could amount to as many as 50 additional deaths every hour, most of them in children under 5. Other studies suggest that the rate of diarrhoeal diseases in children will increase by 5% for every 1°C of temperature rise.

The report shows that last year the direct costs of climate disasters totalled more than $178 billion. Drought affected 19% of the world’s total land surface area, damaging yields of crucial crops such as wheat, corn and soya bean. Extreme heat shut down operations at farms and factories, depriving the world of 295billion work hours.

Curbing emissions, investing in clean energy and funding adaptation efforts could save money and lives, the report says.