In more climate news, the ‘vital signs’ of the Earth’s ecosystem first published by a group of more than 11,000 scientists in 2019 have been updated, with mixed but mostly negative results. Carbon dioxide, methane and nitrous oxide concentrations in the atmosphere are all up, while Arctic, Greenland and Antarctic ice is all down, as is glacier thickness. The ocean heat content is up, while sea level change relative to the 20-year mean is rising. Ocean acidity seems to have stabilised for now, and the surface temperature anomaly (presumably relative to pre-industrial averages) appears not to have worsened over the last five years, though the long-term trend is nevertheless rising. Many indicators show the effect of the COVID-19 pandemic – air transport fell by perhaps two-thirds in 2020, but has bounced back somewhat in 2021, CO₂ emissions fell (and are expected not to exceed the 2019 level this year) and consumption of oil, gas and coal all fell last year, while solar and wind output rose. On the positive side of things as far as the group of scientists is concerned, per capita meat consumption is trending downwards (perhaps as a result of recessions, but also perhaps because of broader behavioural changes), human fertility rates continue to fall, and fossil fuel subsidies also continue to drop, while per-capita CO₂ emissions are also trending downwards (helped by the pandemic). In addition, the number of jurisdictions – many of them local governments – having declared a ‘climate crisis’ (following the scientists’ own declaration in 2019) is now above 2000, and the portion of greenhouse gases covered by carbon pricing has risen sharply. Global tree cover loss has increased somewhat, however, partly because Amazon forest loss is rising, and ruminant livestock numbers are increasing.

Overall, the scientists find that insufficient efforts have so far been made to tackle the climate crisis. They call for an intensifying urgency in addressing:

• energy, eliminating fossil fuels and shifting to renewables
• short-lived air pollutants, slashing soot, methane and hydrofluorocarbons
• nature, restoring and permanently protecting Earth’s ecosystems to store and accumulate carbon and restore biodiversity
• food, switching to mostly plant-based diets, reducing food waste and improving cropping practices
• economy, moving from indefinite GDP growth and overconsumption to ecological economics and a circular economy, in which prices reflect the full environmental costs of goods and services
• human population, stabilising and gradually reducing the population by providing voluntary family planning and supporting education and rights for all girls and young women, which has been proven to lower fertility rates.

These remain very challenging tasks for the world.