From Science Matters

By Ron Clutz

Judges in high courts are all claiming a “Human Right to a Stable Climate,” as though any court, parliament or government can make it happen.  The latest proclamations come from the International Court of Justice and the Inter-American Court of Human Rights ( IACtHR )

The 234-page IACtHR advisory opinion sets out the court’s perspective on the climate emergency and human rights, recognizing that states have legal obligations under international law to protect current and future generations from the impacts of climate change, to take “urgent and effective” action to cut greenhouse gas emissions, to adapt, to cooperate, and to guard against climate disinformation and greenwashing.

Question to perplexity.ai: Could courts’ emphasis on human activity overlook natural climate variability evidence?

Answer: (my bolds) Courts’ emphasis on human activity as the primary driver of recent climate change is based on the strong scientific consensus reflected in assessments by bodies like the IPCC, and courts have generally accepted these conclusions as beyond reasonable dispute when adjudicating climate law cases23. This approach often involves taking “judicial notice” of mainstream climate science, meaning courts regard anthropogenic climate change as an established fact, obviating the need to litigate scientific basics repeatedly23.

However, this legal methodology can, in practice, result in
underweighting evidence of natural climate variability:

• The dominant legal standard centers on whether human-caused disruptions introduce new or heightened risks to rights, rather than parsing the specific historical roles of natural versus anthropogenic drivers6. Thus, courts sometimes set a lower bar for causal linkage, assuming risks to rights where types of harm are deemed foreseeable consequences of climate change, even if local variability or confounding natural factors exist65.
• Defense arguments in litigation, such as those in Juliana v. United States, have challenged the ability of current science to disentangle anthropogenic from natural variability (especially for region-specific impacts), but such arguments are usually overruled or considered less compelling compared to the broader trend evidence53.
• Some court rulings have acknowledged the complexity and multiple contributors to climate outcomes, yet uphold state obligations for mitigation and adaptation, reasoning that even where natural variability exists, the unprecedented pace and scope of human forcing is sufficient to establish state duties under rights frameworks6.

In summary, while courts do not categorically ignore natural climate variability, their emphasis on human activity is guided by prevailing scientific consensus and the precautionary principle. This can lead to less rigorous scrutiny of the full extent of natural variability’s contribution, particularly where the focus is on the foreseeability and scale of rights-endangering risks from ongoing anthropogenic change. Legal recognition of these risks typically does not require natural and human factors to be weighed equally—potentially overlooking specific nuances of natural variability in individual cases653.

Caveat: There are exceptions, and courts have dismissed some claims where causal links to human activity were too indirect or not supported by sufficient evidence, especially in jurisdictions with stricter standards for standing or causation6. However, the overarching trend is to defer to consensus science prioritizing human-driven change as the principal legal concern.

Question to perplexity.ai: Could ignoring natural variability lead to misjudging climate damage extent?

Answer: (My bolds)

Ignoring natural climate variability in assessing climate damage could indeed lead to misjudging the extent and nuances of that damage. Scientific and assessment literature on climate impacts and natural resource damage emphasizes that both natural variability and human-driven climate change influence climate-related hazards and ecosystem responses, and failing to account for natural variability can complicate accurate attribution and magnitude estimation of damage.

Key points synthesized from relevant sources include:

• Baseline Challenge and Detection Difficulty: Climate change increases variability and the frequency of extreme events such as droughts, floods, and storms, but natural variability also influences these patterns. This complicates establishing a stable baseline for comparison. Ignoring natural fluctuations can lead to an under- or overestimate of true climate-related damages, as it is harder to detect how much harm is caused specifically by human activity versus natural cycles5.
• Attribution Complexity: Natural variability introduces uncertainty when attributing specific events or damages to human-caused climate change. Explicitly considering natural variability in event attribution studies increases uncertainty ranges but still supports the conclusion that human activity raises the likelihood and severity of some events. Neglecting natural variability risks oversimplifying cause-effect relationships and could distort the assessment of climate risks and damages6.
• Changing Reference Conditions: The selection of appropriate reference or baseline conditions for assessing injury to natural resources needs to factor in both long-term trends and natural fluctuations altered by climate change. Static references ignoring natural variability may mischaracterize damage extent or recovery needs5.
• Implications for Risk and Damage Assessment: Failure to incorporate natural variability may lead to misjudging vulnerabilities, underestimating risk likelihoods, and misguided policy decisions. Accurate modeling and impact assessment require analysis frameworks that integrate historical variability alongside anthropogenic warming influences27.

In summary, rigorous climate damage and risk assessments seek to integrate natural variability to improve accuracy and avoid misjudging the scale or cause of damage. While natural variability is not a reason to dismiss anthropogenic climate impacts, acknowledging it refines understanding and strengthens attribution and legal or policy responses.

This nuanced view aligns with the legal and scientific approaches courts rely upon when considering climate damage claims: they defer to comprehensive scientific consensus but remain mindful of uncertainties introduced by natural climate variability.

My Comment:

Not seeing much of that nuance from judges blindly following IPCC nostrums.  The right to a stable climate ignores the fact the modern era is full of both warm and cool periods, including many times without any possible human influence.

See Also

Our Weather Extremes Are Customary in History

IPCC Guilty of “Prosecutor’s Fallacy”

How Do We Know Humans Cause Climate Change?