Attribution Science 101

The document introduces attribution science as a method to measure how human-caused climate change affects the likelihood, frequency, and intensity of weather events by comparing current observations with simulated 'counterfactual' worlds. It details Climate Central's specific tools, such as the Climate Shift Index (CSI) for air and sea surface temperatures and the Tropical Cyclone CSI for hurricane wind speeds. The guide distinguishes between different types of attribution—event, trend, source, and impact—and notes that while temperature-related events are highly quantifiable, other severe weather like tornadoes remains an active area of research.

• Event attribution science utilizes advanced computer models and observed data to compare the current carbon-polluted world with a simulated 'counterfactual scenario'—a cooler world without human-caused heat-trapping pollution—to determine how much more likely or intense a weather event has become.
• The ability to quantify the climate change 'fingerprint' varies by weather type: temperature-related events like heat waves can almost always be measured with high confidence, whereas the influence on severe weather such as thunderstorms or tornadoes cannot yet be confidently quantified for specific storms.
• Climate Central has developed three specific attribution tools: the Climate Shift Index (CSI) for daily air temperatures (ranging from -5 to +5), the Ocean CSI for sea surface temperatures (ranging from -1000 to +1000), and the Tropical Cyclone CSI for calculating increases in hurricane wind speeds.
• Attribution science is divided into four subfields: event attribution (specific events), trend attribution (long-term global trends in temperature, precipitation, and sea level), source attribution (tracing pollution to specific industries or entities), and impact attribution (quantifying socio-economic and health consequences).

APA

Climate Central (2025). Attribution Science 101. https://www.climatecentral.org/climate-matters/attribution-science-101

Chicago

Climate Central. Attribution Science 101. 2025. https://www.climatecentral.org/climate-matters/attribution-science-101.

Wikipedia

{{cite report |author=Climate Central |title=Attribution Science 101 |date=3 December 2025 |url=https://www.climatecentral.org/climate-matters/attribution-science-101 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{climatecentral2025attribution, author = {{Climate Central}}, title = {{Attribution Science 101}}, institution = {Climate Central}, year = {2025}, month = dec, url = {https://www.climatecentral.org/climate-matters/attribution-science-101}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }