Five cases where shaky science snowballed into public confusion

Science inches forward on peer review and second thoughts; the news cycle stampedes on novelty and clicks. When those two tempos collide, a worst-case microplastic estimate becomes a story about consuming a “credit card” worth of microplastics each week. Or a speculative insect review morphs into an “apocalypse,” or a complex climate report becomes a simple ’12-year’ deadline. In story after story, slim evidence outruns scrutiny, headlines harden into “facts,” and the public is left sorting myth from correction. The five cases below show how quickly shaky science can snowball, and how difficult it can be to clean-up the narrative once it has taken hold.

Case study 1: Do we really ingest a credit card’s worth of microplastics each week?

Original finding: The eye-popping claim that humans ingest roughly a credit card’s worth of plastic (around 5 grams) each week originated from a 2019 WWF-commissioned meta-analysis from the University of Newcastle. Combining more than 50 datasets on micro- and nano-plastic particles in food, water, and air, it concluded with a wide estimated weekly ingestion range of 0.1 to 5 grams. The 5-gram figure, equivalent to the weight of a credit card, was explicitly presented as a worst-case scenario. The lower end was 1/50th as much. And drinking water (especially bottled) was deemed the worst culprit. Even then, the authors warned of data limitations in the research.

Media coverage and complications: Despite the uncertainty, global media outlets, such as Reuters, widely amplified the upper 5-gram figure. Complicating matters was a related study on flame retardants in recycled plastics, which initially miscalculated a reference safety dose. As a result, the study made potential exposure seem closer to a risk threshold than it actually was. The authors Liu et al. printed a correction in Chemosphere.

Expert corrections: In terms of the former study, a 2022 systematic reassessment published in the Journal of Hazardous Materials Letters by Martin Pletz challenged the 2019 estimate. The critique noted several methodological flaws in the original study. For instance, it included the double-counting of certain exposure routes, the up-scaling of single-location measurements to represent global values, and the mixing of particle-count and mass-based studies without proper harmonization. This re-analysis placed median ingestion values in the low-microgram (µg) per week range. That’s orders of magnitude below the widely publicized 5 grams (Pletz, 2022). The original authors themselves later clarified, as quoted in a media literacy analysis by CheckPlease, that their work was intended to map knowledge gaps rather than declare a definitive personal dose, and that converting particle counts to mass “should be treated as illustrative until better data exist.”

Bottom line: The widely reported “credit card’s worth” of plastic ingestion stemmed from a worst-case scenario in an early meta-analysis with acknowledged data limitations. Subsequent expert reassessments suggest significantly lower amounts, emphasizing the need for caution with preliminary, attention-grabbing estimates.

Case study 2: Is an “insect apocalypse” wiping out bugs everywhere?

Original finding: What was it about 2019? The year also gave birth to the narrative that there was a looming “insect apocalypse” gained global traction following an early 2019 review in Biological Conservation titled “Worldwide decline of the entomofauna: A review of its drivers.” Surveying existing studies, authors Sánchez-Bayo and Wyckhuys concluded that 40% of insect species worldwide could be in decline. The authors suggested that if these trends continued unabated, insects might face extinction within a century. Habitat loss and pesticides, they noted, are major drivers and invoking the grave language of a looming extinction event. “As insects comprise about two thirds of all terrestrial species on Earth, the above trends confirm that the sixth major extinction event is profoundly impacting life forms on our planet,” they wrote.

Media coverage: Mainstream media worldwide seized on this with dramatic headlines. For instance, The Guardian ran with “Plummeting insect numbers ‘threaten collapse of nature.” The paper quoted Sánchez-Bayo: “[The extinction] is very rapid. In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none.” Many outlets extrapolated the study’s findings to imminent global ecosystem collapse. The implication? All insects everywhere were uniformly vanishing.

Expert corrections: Yet the scientific community urged caution in the broad-brush interpretations of data. Entomologists and ecologists highlighed limitations and missing context in the narrative. For instance, a 2020 paper in BioScience by Saunders, Janes, & O’Hanlon argued for “Moving On from the Insect Apocalypse Narrative” in the title of their work. They concluded that recent studies on insect declines had received exaggerated global media coverage.  Talk of an “apocalypse”? Premature and overstated. They called for engaging with evidence-based insect conservation rather than sensationalism. Similarly, a 2020 study in Insect Conservation and Diversity by Didham et al. identified seven core challenges in interpreting insect decline data. Those included issues with establishing proper baselines, biases in site selection, and difficulties in time series analysis. Another paper in the same journal by Saunders, Janes, & O’Hanlon (2020) addressed the semantics of the insect decline narrative. In essence, the media’s frequent one-note narrative of a uniform global collapse that followed the initial 2019 review was an oversimplification.

Bottom line: While genuine insect declines are documented in specific regions and taxa, the narrative of a uniform, imminent “insect apocalypse” driven by a single 2019 review was contested by many experts who pointed to data limitations, regional variations, and the need for nuanced scientific assessment over sensationalism.

Case study 3: Do we really have ‘only 12 years to save the planet’?

Original finding: The oft-quoted deadline traces back to the IPCC’s 2018 Special Report on Global Warming of 1.5 °C. The report warned that to keep warming near 1.5 °C, global CO2 emissions should fall roughly 45% by 2030. The authors, however, did not declare 2030 a cliff-edge for civilizational collapse. Instead, they framed 2030 as a milestone on a continuum of rising risks: the earlier emissions peak, the lower the damages.

Media coverage: Headlines soon distilled the nuanced message into a catchy sound bite: “12 years to save the planet.” BBC asked in 2019. It went on to argue that we had 18 months. The 12-year idea spread so widely that one analysis noted: “The journalists who repeat ’12 years to save the planet’ in their news stories never cite this to the IPCC report by page, section number or quote. Nobody could because this climate slogan is not there.”

Expert corrections: Climate scientists quickly pushed back. IPCC authors clarified that 2030 is not a point of no return; overshooting 1.5°C simply ratchets up impacts rather than triggering instant doom. The Max Planck Institut für Meteorologie states that “1.5°C is not a physical threshold for climate change. There is no clear-cut transition from a safe climate to dangerous climate change“. A Nature comment warned that “setting a climate deadline is dangerous” and could breed public disillusionment if the world passes the date without catastrophe. Another Nature article noted “that it is essential to redirect the overshoot discussion towards prioritizing the reduction of climate risks in both the near term and long term and that overconfidence in the controllability and desirability of climate overshoot should be avoided.” Oxford physicist Myles Allen, an IPCC lead author, has faulted simplistic narratives in addressing climate change. “We must stop fossil fuels causing global warming, before the world stops using fossil fuel,” he said. “We have to capture the carbon dioxide they generate and dispose of it, permanently, back underground,” Forbes quoted him as saying.

Bottom line: The 12-year meme made for punchy headlines but mangled the science. The IPCC called for rapid emissions cuts, not an end-of-days countdown. Treating 2030 as a hard game-over date risks public fatigue.

Case study 4: Does the MMR vaccine really cause autism?

Shark attacks surge when ice-cream sales spike. Nicolas Cage releases a new movie and drownings tick up. Spurious correlations are everywhere, yet most don’t become embedded in the cultural fabric. Yet a retracted 1998 Lancet paper with a sample size of 12 convinced millions that the MMR shot causes autism. Other researchers have been unable to reproduce his findings and the author, Andrew Wakefield was stripped of his medical license in the UK.

Original “finding”: In 1998 gastroenterologist Andrew Wakefield and 12 co-authors published a short case series in The Lancet linking the measles-mumps-rubella (MMR) vaccine to gut inflammation and “regressive autism” in a dozen children. No control group, no epidemiology, but speculation and an n = 12. Wakefield nonetheless recommended breaking up the combined MMR shot and continues to lobby against vaccines at large.

Media coverage: UK tabloids ran alarming stories. BBC had the headline“Child vaccine linked to autism.” TV news juxtaposed worried parents with Wakefield’s press-conference sound bites. U.S. outlets soon echoed the scare. Early pieces often provided “false balance,” giving Wakefield’s fringe view airtime equal to the broader scientific consensus. MMR uptake in England fell from 92% in 1995 to about 80% by 2003. Fast forward to today and the national MMR vaccination coverage among kindergartners is down in the U.S., too. CDC notes that rates have dipped from about 95% in 2019–20 to 93% in 2022–23. Even measles vaccination rates in the U.S. are flagging, contributing to an outbreak of 1,001 confirmed cases reported across 31 states as of 8 May 2025.

Expert corrections: Large population studies, including a 537,303-child Danish cohort (2002) and a 657,461-child one (2019) found no autism signal.

Investigations by journalist Brian Deer uncovered undisclosed legal-aid funding and manipulated data. In a  BMJ article, he called the Wakefield paper fraud. In 2010,The Lancet fully retracted the paper the same year.

While the precise causes of autism spectrum disorder (ASD) remain unclear, the condition is “highly heritable,” as a 2019 Nature article noted. Gestational exposure to certain pesticides appears to be another contributor.

Bottom line: A single, fatally flawed study that credulous headlines amplified seeded a durable vaccine myth. Wakefield lost his license, the paper was retracted, but the public-health damage still echoes in lowered vaccination rates and renewed outbreaks.

Case study 5: Did astronomers really find life in Venus’s clouds?

Original finding: In September 2020, Jane Greaves led an international team reporting a faint spectral line at 1.12 mm in Nature Astronomy. The researchers interpreted the finding as phosphine (PH₃) floating about 55–65 km (30-plus miles) above Venus. On Earth, microbes or industrial chemistry are the typical source of phosphine. Another scientist called the findings “curious and unexplained.”

Media coverage: Nuance evaporated faster than Venusian sulfuric acid. Headlines shouted “Astronomers may have found a signature of life on Venus” and “Scientists find gas linked to life on Venus.” BBC News ran an explainer, “Is there life floating in the clouds of Venus?” “The team emphatically is not claiming to have found life on Venus, only that the idea needs to be further explored as scientists also hunt down any overlooked geological or abiotic chemical pathways to phosphine,” the publication wrote. Television segments led with artists’ renderings of floating alien microbes. Tweets, podcasts and late-night monologues giddily declared we’d found our cosmic neighbor.

Expert corrections: Within a year, multiple teams re-processed the raw data and pointed out calibration quirks and sulfur-dioxide confusion. An Editor’s Note appended to the original Nature Astronomy paper just two months after publication, in November 2020, cautioned readers about errors in the ALMA data processing and their impact on the conclusions. Independent analyses using ALMA and the JCMT failed to recover a clear phosphine signal; one study concluded there was “no trace” down to detection limits. Even Greaves’s group revised its inferred PH₃ abundance downward by approximately 20-fold (from an initial ~20 ppb to revised estimates in the low single-digit parts-per-billion range). Planetary chemists added that, even if a few parts-per-trillion of phosphine lurk in the clouds, acid rain, 460°C surface temperatures and crushing pressures make a thriving biosphere wildly speculative.

Bottom line: A single, low-signal spectrum morphed into global “life on Venus” headlines overnight. Follow-up work suggests the blip was likely noise.