{
  "question": "In a frozen NASA GISTEMP v4 annual global land-ocean series, how sensitive is evidence for a slope increase near 2015 to endpoints and autocorrelated noise?",
  "scope": "A conditional audit of one unadjusted temperature series, not causal attribution, future prediction, or reproduction of adjusted five-dataset analyses.",
  "prior_knowledge": "Read published summaries and methods of Foster and Rahmstorf 2026; downloaded NASA CSV before registration but have not inspected values, fitted regressions or computed statistics. Published warming and acceleration findings are known.",
  "data": {
    "url": "https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.csv",
    "source_column": "J-D",
    "start": 1970,
    "endpoints": [
      2025,
      2024,
      2022
    ],
    "complete_years_only": true,
    "partial_2026": "excluded; require twelve finite monthly entries for every analysis year",
    "snapshot": "downloaded during session, exact bytes and SHA256 retained"
  },
  "primary": {
    "model": "OLS continuous linear spline: anomaly = intercept + beta*(year-1970)/10 + delta*max(0,year-2015)/10 + residual",
    "endpoint": 2025,
    "knot": 2015,
    "delta_units": "degree Celsius per decade",
    "null": "delta=0",
    "covariance": "Newey-West Bartlett HAC with maxlag=3 and n/(n-3) finite sample multiplier",
    "interval": "two-sided 95% normal approximation",
    "report": [
      "slopes",
      "delta",
      "standard error",
      "interval",
      "two-sided p",
      "residual lag-one correlation"
    ]
  },
  "sensitivities": {
    "fixed_knot": 2015,
    "endpoints": [
      2025,
      2024,
      2022
    ],
    "HAC_lags": [
      0,
      1,
      3,
      5
    ],
    "iid_OLS": "conventional t interval also reported",
    "interpretation": "all sensitivity intervals and p-values descriptive without additional confirmatory claims"
  },
  "selection_adjusted_test": {
    "statistic": "largest extra-sum-of-squares F for adding one hinge to linear trend, over integer knots from 1985 through min(2015,endpoint-10)",
    "null": "linear trend with stationary Gaussian AR(1) residuals",
    "rho": "OLS regression of null residual e[t] on e[t-1], clipped to [-0.95,0.95], clipping reported",
    "innovation_sigma": "sqrt(mean((e[t]-rho*e[t-1])**2))",
    "simulation": "stationary initial residual, recursive AR(1), same years and refitted linear and hinge regressions in every replicate",
    "B": 10000,
    "seed": 20261006,
    "rng": "numpy PCG64",
    "endpoints": [
      2025,
      2024,
      2022
    ],
    "p": "(1 + number simulated maxF >= observed maxF)/(B+1)",
    "MC_uncertainty": "report conditional binomial Monte Carlo standard error and Wilson 95% interval",
    "iid_comparison": "repeat same maxF test with rho=0 and residual standard deviation sqrt(SSE/(n-2))",
    "parameter_sensitivity": "at endpoint2025 repeat AR1 calibration with rho fixed to 0.2,0.4,0.6 and null innovation sigma recomputed",
    "power": "endpoint2025 AR1 plug-in null parameters with true knot2015 and slope increases 0.1,0.2,0.3 C/decade; reject using 95th percentile of corresponding simulated maxF distribution; 5000 replicates per effect, binomial standard error; no data-derived effect used to select alternatives"
  },
  "validation": [
    "separate scalar least-squares refits for selected and subset simulated statistics vs vectorized projection implementation",
    "HAC covariance cross-check against statsmodels if available",
    "deterministic self-reproduction in offline pinned Docker image",
    "complete endpoint and year uniqueness checks",
    "report all planned analyses including non-significant results"
  ],
  "claim_rules": [
    "Only numerical claims about the frozen data and specified conditional models",
    "No inference that a non-significant test establishes no acceleration",
    "No novelty or priority claim",
    "The fixed knot was informed by literature, not discovered prospectively",
    "An AR1 null is a conditional approximation and omits climate forcing, ENSO and observational uncertainty"
  ],
  "publication": "Report plan and all computations in one bundle; deviations explicit; hazard none after review."
}