Recently, a German court dismissed an action brought by a Peruvian farmer, Saúl Luciano Lliuya, against a German power company, RWE1. The basis of the case was that the global emissions of RWE had contributed to the melting of glaciers in Peru, and thus increased the risk that Lliuya’s home town would flood.
He sought damages in order to build a flood defence for his home town, which were based on the assertion that RWE were responsible for 0.5 per cent of the world’s total CO2 emissions and thus should be responsible for 0.5 per cent of the cost of flood defences for the town.
RWE’s case was largely that global warming was a global problem, and that it should not be singled out. Interestingly, the court ruled that the case had merit to the extent that RWE could be held liable for its CO2 emissions, and that German nuisance law could be utilised by people living far from Germany to pursue such claims.
The matter was ultimately dismissed because the court found that the increased flood risk to Lliuya’s home town was not significant, not because the damage was too remote; that RWE was not active in Peru did not seem to be a factor.
Whether this triggers a flood of climate litigation is yet to be seen. While one court in Germany has accepted the potential for emitters to be held liable, there would seem to be plenty of scope for further debate. While it is clear human activities are warming the globe, tying particular companies to specific climate changes is a trickier prospect and most likely beyond our current forensic science.
Of real concern, however is that the case has prompted calls from climate activists to address the ‘David versus Goliath’ element in such matters by reversing the onus of proof2. While that often seems like a good idea when the defendant is seen as self-evidently ‘bad’, this does not sit well with natural justice.
The obligation on the plaintiff to prove its case is a fundamental tenet of the rule of law, and has been around since ancient Rome, via the maxim Onus probandi incumbit ei qui dicit, non ei qui negat – the burden of proof lies with the one who speaks, not the one who denies3.
Having the burden of proof sit with the plaintiff is fundamental to affording natural justice, and it is not something that should be reversed on a political whim, or because the defendant is not liked. Lawyers have a duty to the court and the administration of justice, and consequently an obligation to stand up for the rule of law – even when that puts us on the side of an apparently unpalatable defendant.
With social-justice type cases in the climate change space (and many other areas) becoming more common, it is likely that the calls to reverse the onus in such cases will get louder. From a rule of law point of view, however, those calls must be resisted. Reversal of onus is a concept against which the whole profession should unite; such principles should not be up for negotiation, no matter who the defendant is.
Footnotes
1 https://www.bbc.com/news/articles/c5y5lwveqzno
2 Climate Justice, New Scientist 3 May 2025 No3541, p21
3 https://www.qlsproctor.com.au/2023/12/vale-the-presumption-of-innocence/
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