This week’s environment round-up looks at the search for sustainable wellbeing, the vast fungal networks keeping ecosystems alive, and the likelihood of warming exceeding 1.5°C before 2030.

Females lead way to environmentally sustainable human wellbeing

The Health Planet Index (HPI) measures how successfully nations are achieving sustainable wellbeing now, while ensuring that others can do the same in the future. Countries that are performing well achieve high levels of health and life satisfaction (referred to as “Adjusted Happy Life Years”), while maintaining low ecological impact. The latter is measured as the global hectares (gha) of the planet’s surface required to sustain an average resident’s consumption pattern.

Another way of looking at the HPI is as a measure of how much wellbeing is achieved per unit of environmental resource consumed. Mathematically, it is represented as:

HPI = (Life expectancy X self-reported wellbeing (Adjusted Happy Life Years)) ÷ ecological footprint

The 2026 Healthy Planet Index report presents data for 134 countries up to 2025.

No country achieves “sustainable wellbeing”. The highest ranking country is Costa Rica with an HPI of 68 per cent. Then there’s a sharp drop to 60 to 61 per cent for the next seven countries. There are distinct continental-scale patterns evident in the map below. Latin America stands out as the best performing region, followed by Europe. Asia is mixed. North America, Australia and Africa are poor performers.

The graph below is a scatter plot of Adjusted Happy Life Years and Ecological Footprint. Some countries are doing better than others at achieving high levels of health and happiness, while some are better at keeping their ecological footprint low. Some are even moving toward both good health and a low footprint. (It’s important to note that the scatter plot indicates an association between the two variables, not a causative relationship.)

Australia achieves very good health but with an unfortunately high demand on the environment – hence its low HPI.

The plot also demonstrates that:

On the left side, there is a strong positive association between Adjusted Happy Life Years and Ecological Footprint – at low levels of both, improving health and increasing ecological impact go hand in hand. But (and it’s a crucial but) beyond about 75 Adjusted Happy Life Years and four hectares per person there is no improvement in health as the ecological impact increases: trashing the environment isn’t associated with happier, healthier people.

At any particular level of environmental impact (look at........

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