Historical Perspective:
A couple of decades ago, the U.N. Intergovernmental Panel on Climate Change (IPCC) maintained that individual weather events couldn't be attributed to climate change.
Over time, scientific understanding has evolved, allowing researchers to attribute some extreme events to climate change despite inherent uncertainties.
Current Challenges and Usage:
Scientific and data challenges persist in the attribution of extreme events to climate change.
Attribution outcomes are used to estimate richer countries' historical liability for climate-related 'loss and damage' (L&D) and assess legal liability for adverse events like floods and droughts.
Various methods are used for attribution, raising questions about the maturity of this science for use in legal and multilateral contexts.
Value of Extreme-Event Attribution
Importance for 'Loss and Damage':
No formal cost-benefit analysis of attribution exercises exists, but experts argue they are critical for the L&D process.
L&D lacks a unique definition but has gained importance in climate talks under the U.N. Framework Convention on Climate Change.
Demands from Developing Countries:
Economically developing countries, especially those 'particularly vulnerable', demand L&D funds to compensate for climate change-induced damage.
The criteria for identifying 'particularly vulnerable' countries are crucial.
Case of India:
As a developing country highly vulnerable to climate change, India is unlikely to qualify for L&D funding.
This raises the question of whether climate finance should focus solely on adaptation and mitigation or also include L&D funds.
Legal Accountability Concerns:
Developed countries oppose legal accountability for extreme events to avoid potential lawsuits.
Understanding whether attribution reports can be used as evidence of culpability in court is essential.
Attribution of Asian Heatwaves
Recent Attribution Report:
A recent report by World Weather Attribution (WWA) found that climate change made heatwaves across Asia nearly 45 times more likely.
The process involves comparing conditions during the heatwaves with a counterfactual world without climate change.
Methodology:
The counterfactual world is modeled based on available data, running climate models without increased greenhouse gas emissions.
Data insufficiency, especially for rainfall, poses a significant challenge, while models are better at capturing temperature-related events at regional scales.
Implications and Future Actions
Hyperlocal Attribution Challenges:
Reliable hyperlocal attribution remains a future goal, but moral questions about subsequent actions persist.
Attribution exercises need to be integrated with governments' adaptation and mitigation strategies.
Impact on Population and Businesses:
Identifying hotspots of extreme events could influence people and businesses to relocate.
Governments must respond to such decisions, and attribution science needs to be reliable.
Selection of Extreme Events for Attribution
Event Selection Challenges:
Scientists face challenges in selecting which extreme events to attribute.
The WWA used regional scales and varying definitions, considering daily, three-day, or monthly average temperatures.
Natural and Human Factors:
Heatwaves can be influenced by natural factors (e.g., El Niño) and human activities (e.g., urbanization, deforestation).
Weather events are unique, making reliable attribution easier on a subcontinent scale than on a local scale.
Scientific Questions:
Different scientific questions can yield different answers from the same analysis (e.g., intensity vs. frequency of heatwaves).
The WWA report used multiple approaches to answer attribution questions, but the materiality of differences in a legal context remains unclear.
Human Action and Extreme Events
The impacts of extreme events depend on the hazard and the vulnerability and exposure of the affected population.
Financial consequences are also influenced by various factors, raising the question of whether attribution should consider impacts.
Reliable attribution is vital for L&D negotiations.
Governments should agree on historical responsibilities to fund developing countries, build adaptation capacity, and finance mitigation efforts.
In a resource-constrained world, a cost-benefit analysis of attribution exercises is necessary.
Clear roles for attribution in the overall climate action landscape must be established.
COMMENTS