claim: "The Pacific Decadal Oscillation (PDO) is a temperature pattern in the Pacific Ocean that spends roughly 20-30 years in the cool phase or the warm phase.
evidence: Thresholds and boundaries The threshold, or tipping point, is the value at which a very small increment for the control variable (like CO2) triggers a larger, possibly catastrophic, change in the response variable (global warming) through feedbacks in the natural Earth System itself.