Uncertainty is measurable across science and policy, not a vague afterthought. The IPCC AR6 estimates equilibrium climate sensitivity at 3°C, with a likely range from 2.5 to 4°C and a 66% probability, while Arctic sea ice extent shifts by about ±0.5 million km² each year. Economic uncertainty shows up too, with the US Economic Policy Uncertainty Index averaging 150.2 in 2023 against a historical average near 100.
Key Takeaways
- IPCC AR6 estimates equilibrium climate sensitivity (ECS) at 3°C (2.5-4°C likely range, 66% prob).
- Global temperature rise uncertainty: 1.5°C target breached by 202x with 50% prob (CMIP6).
- Sea level rise by 2100: 0.28-1.01m (median 0.6m, RCP4.5).
- The US Economic Policy Uncertainty (EPU) Index averaged 150.2 points in 2023, indicating elevated uncertainty compared to the historical average of 100.
- Global EPU Index reached a peak of 250.4 in March 2020 due to COVID-19, 2.5 times the long-term average.
- In the Eurozone, EPU Index stood at 178.6 in Q4 2023, driven by geopolitical tensions.
- VIX futures curve inverted 15% of time in 2023, signaling uncertainty.
- Implied volatility for S&P 500 options averaged 22% in 2023.
- MOVE Index (bond volatility) peaked at 160 in March 2020.
- Diagnostic uncertainty in cancer diagnosis: 10-20% error rate.
- Treatment efficacy uncertainty: 30% of RCTs show <50% confidence in effect size.
- COVID-19 case fatality rate uncertainty: 0.5-1.5% (early 2020 est).
- Psychometric test-retest reliability: r=0.85 (SEm=4.7 pts).
- Intolerance of Uncertainty Scale (IUS-12) mean: 28 (SD=10).
- Decision under uncertainty: Prospect theory loss aversion λ=2.25.
Uncertainty remains high across climate and markets, from ECS and sea level to volatility and EPU.
Related reading
01 · Category
Climate Uncertainty18 stats
01
IPCC AR6 estimates equilibrium climate sensitivity (ECS) at 3°C (2.5-4°C likely range, 66% prob).
02
Global temperature rise uncertainty: 1.5°C target breached by 202x with 50% prob (CMIP6).
03
Sea level rise by 2100: 0.28-1.01m (median 0.6m, RCP4.5).
04
Arctic sea ice extent min uncertainty: ±0.5 million km² annually.
05
Extreme precipitation freq increase: 7% per 1°C warming (95% conf).
06
Carbon budget for 1.5°C: 500 GtCO2 (66% prob from 2020).
07
TCRE (transient climate response to emissions): 1.65°C/TtCO2 (90% conf 1.0-2.3).
08
Cloud feedback uncertainty: +0.42 W/m²/K (±0.42 range).
09
Ocean heat uptake efficacy: 0.8 (range 0.5-1.1).
10
Permafrost carbon release: 10-100 GtC by 2100 (high uncertainty).
11
Aerosol forcing: -1.3 W/m² (-2.0 to -0.6, 90% conf).
12
Historical warming attribution: 100% human (very likely >50%).
13
Tipping point prob (AMOC collapse by 2100): <10% (low conf).
14
Crop yield sensitivity: -5% per 1°C (with ±20% unc).
15
Hurricane intensity increase: 5-10% per °C (medium conf).
16
Biodiversity loss prob: 20-30% species at risk by 2100 (RCP8.5).
17
Radiative forcing uncertainty: ±0.5 W/m² for total anthropogenic.
18
ECS probability dist: 5-10% chance >5°C.
Interpretation
Climate Uncertainty Interpretation
The IPCC’s latest report serves up a daunting menu of climate uncertainties, each seasoned with probability ranges that together say we are gambling with the planet’s future using disturbingly fuzzy dice.
02 · Category
Economic Uncertainty20 stats
01
The US Economic Policy Uncertainty (EPU) Index averaged 150.2 points in 2023, indicating elevated uncertainty compared to the historical average of 100.
02
Global EPU Index reached a peak of 250.4 in March 2020 due to COVID-19, 2.5 times the long-term average.
03
In the Eurozone, EPU Index stood at 178.6 in Q4 2023, driven by geopolitical tensions.
04
UK's EPU Index averaged 120.5 in 2022, highest since Brexit referendum.
05
China's EPU Index hit 300+ in 2022 amid zero-COVID policy shifts.
06
EPU Index correlates with -0.45 with US GDP growth over 1985-2023.
07
1% increase in EPU reduces investment by 3.5% within a year, per Baker et al. (2016).
08
VIX Index (fear gauge) averaged 25.4 in 2022, vs. long-term 19.7.
09
During 2008 crisis, VIX peaked at 80.86 on Nov 20, 2008.
10
Uncertainty shocks explain 20% of US business cycle fluctuations.
11
Firms delay hiring when EPU rises above 150, per 2021 study.
12
Brazilian EPU Index averaged 220 in 2023, highest in emerging markets.
13
Japanese EPU at 140 in 2023, linked to yen volatility.
14
Indian EPU peaked at 400 during 2016 demonetization.
15
EPU forecast error for GDP is 1.2% higher per 100-point rise.
16
Small firms' investment more sensitive to EPU, dropping 6% per 100-point increase.
17
EPU Granger-causes stock returns with -0.3 coefficient over 1985-2020.
18
During trade wars, US-China EPU averaged 350 in 2019.
19
EPU reduces R&D spending by 4.2% per standard deviation shock.
20
Historical EPU average (1985-2023) is 112 for US, with std dev 65.
Interpretation
Economic Uncertainty Interpretation
The world's economic dashboard is currently lit up with more warning lights than a Christmas tree, as policy uncertainty from Washington to Beijing makes businesses hesitate on hiring and investment, which historically acts like a lead weight on growth.
03 · Category
Financial Market Uncertainty20 stats
01
VIX futures curve inverted 15% of time in 2023, signaling uncertainty.
02
Implied volatility for S&P 500 options averaged 22% in 2023.
03
MOVE Index (bond volatility) peaked at 160 in March 2020.
04
OVX (oil volatility) averaged 40 in 2022 amid Ukraine war.
05
Realized volatility of Bitcoin was 65% annualized in 2023.
06
GARCH models show uncertainty persistence of 0.95 for equities.
07
2022 saw 25% of trading days with >2% S&P moves.
08
Credit default swap spreads widened 200bps in banking crisis 2023.
09
FX volatility (USD/EUR) hit 12% annualized in 2022.
10
Gold volatility averaged 18% in 2023, hedging uncertainty.
11
Skewness in equity returns increased to -0.5 in high uncertainty periods.
12
Jump risk premium is 5% higher during VIX>30.
13
Tail risk (VaR 1%) worsened to -6% daily in 2020 crash.
14
Dispersion in analyst forecasts rose 30% when VIX>25.
15
Crypto market cap volatility 80% vs. stocks 20% avg.
16
LIBOR-OIS spread averaged 50bps in 2023 stress.
17
Equity risk premium rose to 6.5% in 2022 uncertainty.
18
Options gamma exposure hit records in 2023, amplifying vol.
19
Comovement of stocks increases 40% in high vol regimes.
20
High-frequency trading share drops 15% during vol spikes.
Interpretation
Financial Market Uncertainty Interpretation
While the VIX curve inverted only 15% of the time in 2023, a cacophony of spiking bond, oil, and crypto volatilities, widened credit spreads, and harried market behavior reveals that uncertainty wasn't just signaled—it was the lead actor, demanding a 6.5% premium and turning every minor options trade into a potential plot twist.
04 · Category
Health Uncertainty21 stats
01
Diagnostic uncertainty in cancer diagnosis: 10-20% error rate.
02
Treatment efficacy uncertainty: 30% of RCTs show <50% confidence in effect size.
03
COVID-19 case fatality rate uncertainty: 0.5-1.5% (early 2020 est).
04
Vaccine effectiveness wanes 20-40% after 6 months (Omicron).
05
Antibiotic resistance prediction uncertainty: 50% failure rate by 2050 models.
06
Genetic testing false positive rate: 5-10% for BRCA1/2.
07
Long COVID prevalence uncertainty: 10-30% of cases.
08
Dementia diagnosis accuracy: 70-90% inter-rater agreement.
09
Blood pressure measurement variability: ±5 mmHg within-visit.
10
Surgical outcome prediction models AUC: 0.75 (moderate unc).
11
Rare disease diagnosis delay: 5-7 years avg, 20% misdx.
12
Mental health dx reliability (kappa): 0.4-0.6 for depression.
13
Imaging interpretation discordance: 20% for mammograms.
14
Prognosis uncertainty in ICU: 25% calibration error.
15
Drug interaction prediction accuracy: 85% (false neg 15%).
16
Obesity risk heritability uncertainty: 40-70% variance.
17
Sepsis mortality prediction: SOFA score C-stat 0.74.
18
Alzheimer's biomarker uncertainty: 15% false pos amyloid PET.
19
Tolerance to uncertainty scale (TUS) avg physician score: 45/75.
20
Lab test reproducibility: 10% CV for troponin assays.
21
Heuristic bias in dx: 30% error attribution to unc.
Interpretation
Health Uncertainty Interpretation
In the grand, humbling theater of medicine, we are all simultaneously experts and amateurs, wielding sharp tools on a canvas that stubbornly blurs, which is why the wise physician carries not just a stethoscope but also a healthy dose of doubt.
05 · Category
Psychological Uncertainty15 stats
01
Psychometric test-retest reliability: r=0.85 (SEm=4.7 pts).
02
Intolerance of Uncertainty Scale (IUS-12) mean: 28 (SD=10).
03
Decision under uncertainty: Prospect theory loss aversion λ=2.25.
04
Ambiguity aversion: 70% prefer known prob over unknown.
05
Anxiety disorder prevalence tied to high IU: OR=2.5.
06
Cognitive bias unc: Confirmation bias affects 85% judgments.
07
Overconfidence calibration: 75% accuracy claimed vs 60% actual.
08
Risk perception distortion: People overweight 1% risks by 10x.
09
Wu-Yang ambiguity index: 0.3 avg in experiments.
10
Mindfulness reduces IU by 15% post 8-week MBSR.
11
Choice under unc: Ellsberg paradox replicated in 65% subjects.
12
Self-efficacy uncertainty: Bandura scale SD=8/100.
13
Attributional ambiguity in stereotypes: 40% variance.
14
Future time perspective unc: Shortens by 20% in depression.
15
Neuroticism correlates r=0.45 with IU trait.
Interpretation
Psychological Uncertainty Interpretation
We are reliably inconsistent creatures, who overthink known risks, dread the unknown, and are often confidently wrong about both.
06 · Category
Scientific Measurement Uncertainty18 stats
01
Standard uncertainty in IQ tests: ±3 points (68% conf).
02
Type A uncertainty in length metrology: 0.1 μm for 1m gauge.
03
Monte Carlo method error for dose calc: <2% (k=1).
04
Propagation of uncertainty formula: δy = sqrt(∑(∂y/∂xi * δxi)^2).
05
Coverage factor k=2 for 95% conf interval in normal dist.
06
Bias uncertainty in pH meters: ±0.02 units.
07
Combined std uncertainty u_c = 1.2% for mass balances.
08
Expanded uncertainty U=95% conf = 2 * u_c in metrology.
09
Degree of equivalence |D_b,i| < 1.5 μm in CCM key comp.
10
Random uncertainty dominates 70% in low-precision sensors.
11
Systematic error correction uncertainty: ±0.5% post-calib.
12
Sensitivity coefficient matrix in multivariate unc prop.
13
Welch-Satterthwaite approx df=15 for effective freedom.
14
Particle size dist uncertainty: 5% RSD via laser diffraction.
15
Thermal expansion coeff unc: ±1e-6 /K for steel.
16
Flow rate meter unc: 0.5% (k=2) for turbine meters.
17
Refractive index unc: 1e-6 at 589nm for air.
18
Voltage standard Josephson unc: 0.15 parts in 10^9.
Interpretation
Scientific Measurement Uncertainty Interpretation
The universe whispers its secrets with a margin of error, so whether you're measuring IQ, steel, or the very fabric of reality, remember that certainty is just a confidence interval in a world ruled by witty, unyielding uncertainty.
Reference
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APA
Sophie Moreland. (2026, February 27). Uncertainty Statistics. Gitnux. https://gitnux.org/uncertainty-statistics
MLA
Sophie Moreland. "Uncertainty Statistics." Gitnux, 27 Feb 2026, https://gitnux.org/uncertainty-statistics.
Chicago
Sophie Moreland. 2026. "Uncertainty Statistics." Gitnux. https://gitnux.org/uncertainty-statistics.
Sources & references
52 datasets cited across this report · attribution is report-level