The OWID Brief: Wildlife populations, climate change & malaria, oil production, and more.

1. Key Themes

Headline statistics often mislead: read the methodology behind the number

The Living Planet Index's "73% decline" is routinely misreported, and the article stresses the distinction between an average population change and a loss of animals or species.

"Some may report that the world has lost '73% of animal populations since 1970' or '73% of species are in decline'. Neither of these is correct, and the report's authors go to great lengths to stress this."

"Instead, the Living Planet Index captures the average decline in population numbers across almost 36,000 populations. These changes are then averaged using a geometric mean and given different weightings in the final index."

"When we dig beneath the headline number, we find that around half of the studied populations have declined, but just as many have either increased or remained stable."

Climate change effects are heterogeneous, and human interventions can dominate climate effects

For malaria, climate change shifts the geography of disease more than the overall burden, and intervention effects have dwarfed climate effects.

"Malaria is a very temperature- and rainfall-sensitive disease. This means it's one whose distribution and severity could change a lot in a warming climate."

"Malaria rates have likely decreased in West Africa due to climate change. This is because warming has pushed temperatures in this subregion beyond malaria's optimum temperature of around 25°C. In other parts of Africa, higher temperatures have pushed it towards the optimum, increasing the prevalence."

"Overall, the impacts of interventions to reduce malaria — bed nets, antimalarials, and improved healthcare — have far outweighed the impacts of climate change."

"What's most uncertain about these projections is the impact of extreme weather events. When these are modeled, some project an increase in malaria cases and deaths, due to the shocks on healthcare and malaria control systems."

Energy markets: US dominance in oil and falling per-capita electricity in the UK

Two data points suggest structural shifts in energy supply and demand.

"When people think about global oil, their minds often go toward countries in the Middle East. But it's the United States that is the world's largest oil producer."

"As you can see, the US has been the largest producer for the last nine years, since it overtook Saudi Arabia. Production in the US gradually declined during the 1990s and early 2000s, then increased sharply after 2010 and is now at an all-time high."

"Electricity generation per person in the United Kingdom has fallen by a third from its early-2000s peak" (Data Insights headline)

Agricultural productivity as a conservation lever, plus continued gaps in global health delivery

Featured articles link crop yields to biodiversity outcomes, and point to untapped lifesaving potential in HIV treatment.

"Habitat loss is the biggest threat to the world's animals. Without improvements in crop yields, thousands of species could see much of their habitat lost to farmland."

"Since the late 1980s, antiretroviral therapy has already saved millions of lives from HIV/AIDS. But millions of people with HIV still aren't getting this life-saving treatment."

AI risk policy: the most effective policies are judged the least likely to happen

A Forecasting Research Institute survey reveals a gap between efficacy and feasibility.

"As the authors put it, 'the policies most expected to reduce risk were also the ones that respondents thought were least likely to be implemented'."

"Experts estimated that pairing an international body that vets the most advanced AI models before release, with a US–China slowdown, and strict liability for AI labs, would cut the risk by about 72%, though they only gave it a 1% chance of happening by 2030."

2. Contrarian Perspectives

"73% of wildlife lost" is not what the data says

The consensus headline conflates an index of average population change with absolute loss. The evidence: the index covers a sample of populations, and the declines are not uniform.

"Around half of the studied populations have declined, but just as many have either increased or remained stable."

"It's a bit more complicated than a 'we've lost 73% of wildlife' headline might suggest."

Climate change may reduce, not increase, malaria in Africa overall

Against the intuitive view that warming worsens vector-borne disease, the cited research finds a net decline in prevalence, with caveats.

"Overall, the authors expect a decline in malaria prevalence in Africa due to climate change, with an increase in certain areas that have not experienced the disease for a long time."

"Climate change has likely increased the prevalence of malaria in children across Africa by a rate of 1 case per 1,000 children. To put this into context, there were around 240 cases in every 1,000 children in this region at the time. So, the impact has been relatively small and is uncertain."

Expert AI catastrophe estimates are low, even as policy support is conditional

The median expert's estimate of AI-caused catastrophe by 2050 is modest relative to popular narratives.

"Each respondent first gave their estimate of the odds that AI would cause a catastrophe that would kill more than 10% of humanity by 2050 (the median expert said 2%)."

3. Companies Identified

No operating companies are discussed. Organizations and data sources mentioned:

Our World in Data

Nonprofit publisher of data-driven research. Mentioned as the newsletter's author.

"We are a nonprofit, building Our World in Data as a public good that's freely available to everyone."

Energy Institute (Statistical Review of World Energy)

Source of the oil production data underpinning the US-leads-global-production finding.

"This data comes from the Energy Institute's Statistical Review of World Energy."

Forecasting Research Institute

Runs expert panel surveys on AI risk and policy.

"The Forecasting Research Institute regularly asks a panel of experts to predict how AI will play out."

4. People Identified

Hannah (OWID author)

Author of the Living Planet Index and malaria articles.

"Read Hannah's article" (linked for both the wildlife and malaria pieces)

Colin Carlson

Lead author of a Nature paper on climate change and malaria.

"We draw on a recent paper by Colin Carlson and colleagues, published in Nature, which attempts to answer this question."

Karl Deisseroth, Peter Hegemann, and Georg Nagel

2025 Nobel laureates in medicine for optogenetics.

"It went to Karl Deisseroth, Peter Hegemann, and Georg Nagel for optogenetics... Researchers use it to turn single nerve cells in a living brain on and off with light."

"Deisseroth's lab used it in 2005 to make rat nerve cells fire with blue light."

Max and Bastian (OWID team members)

Authors of the "What we've been reading" recommendations on the Nobel Prize and AI policy surveys, respectively.

5. Operating Insights

Interrogate the construction of any headline metric before acting on it

The Living Planet Index shows how weighting and averaging choices (geometric mean, population sampling) can produce a number that sounds like a total loss but measures something different. Before basing decisions or communications on a statistic, check what is actually being measured.

"The Living Planet Index captures the average decline in population numbers across almost 36,000 populations. These changes are then averaged using a geometric mean and given different weightings in the final index."

Model heterogeneity, not just aggregate effects

The malaria analysis shows a single driver (warming) producing opposite effects in different regions depending on proximity to an optimum. Aggregate averages can hide winners and losers, which matters for market, risk, or exposure analysis.

"In other parts of Africa, higher temperatures have pushed it towards the optimum, increasing the prevalence."

Tail-risk shocks to delivery systems can matter more than the base trend

The most uncertain malaria projections stem from disruptions to healthcare and control systems, not temperature itself. For operators, resilience of delivery infrastructure may matter more than the central forecast.

"Some project an increase in malaria cases and deaths, due to the shocks on healthcare and malaria control systems."

6. Overlooked Insights

Optogenetics is already moving toward clinical vision restoration

A brief mention near the end of the Nobel write-up hints at a translational pathway for a basic-science breakthrough, a potential signal for neurotech and biotech watchers.

"Near the end, it mentions an ongoing trial in which a blind person wearing special light-emitting glasses could again make out objects on a table and reach for them."

Latin America is aging faster than Europe, a demographic shift with long-run market implications

Mentioned only as a Data Insights headline, but relevant for long-term demand, labor, and healthcare planning.

"Europe is older, but Latin America is aging faster" (Data Insights headline)