A candle in the wind

ABSTRACT

Soil is the biggest brake on global heating. It holds more carbon than the atmosphere and all standing vegetation together but farmers have been burning off soil organic matter for 12000 years: they are responsible for one-third of greenhouse gas emissions. The best thing they could do for the planet is to put it back again, and the best place to start is the best soil in the world – the Black Earth of the steppes, prairies and pampas. Half of its organic matter has been pumped into the air and 35 years of satellite measurements reveal a significant loss of primary productivity across the steppes. Conservation Agriculture can haul back the carbon deficit, increase yields and save 60–70% on fuel, fertiliser and labour; the green biomass can support livestock and/or generate biogas. Ukraine and Moldova were set to adopt this system and phase out their coal-fired power stations when the Russian army invaded Ukraine. The best soil in the world is now being put to other uses; we face a global food crisis; and the world’s decision makers have yet another excuse to defer serious efforts to mitigate climate change.

KEYWORDS:

• Black Earth
• carbon capture
• war
• food security

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1. Moon [8] records a five-fold expansion of arable across the steppes from 1725 to 1887. By the 20^th century, virgin steppe survived only in patches. On the Great Plains of North America and the Pampas, the plough moved in at the end of the 19^th and beginning of the 20^th century but degradation has been intensified by the replacement of teams of horses by machinery with hundreds of horse power. Industrialised farming reached Heilongjiang, in China, only in the 1960s.

2. The pre-industrial concentration of CO₂ in the atmosphere was 280 ppm: land use change and burning fossil fuels have boosted it beyond 400 ppm. This is forcing global heating. To hold global temperatures within 1.5°C of the pre-industrial level, emissions must be halved by 2030, eliminated by 2050 and, then, the excess greenhouse gases must be hauled back [9]. For comparison, UK annual emissions in 2021 were 367Gt, Ukraine’s 233Gt.

3. More would be better but this is achievable: in 1990, within the Soviet Union, Moldova devoted 300000 ha to rotational forage crops, producing 9.8 million tonnes of green mass.

4. In 1990, Ukraine devoted 1.4 million ha to leguminous forage, producing 46.5 million tonne of green mass.

5. Macbeth in Macbeth, Act V, scene v. William Shakespeare.