feat: new plot with temps closing in to 1.5°C

README.md

@@ -165,6 +165,36 @@ $ ./hadcrut5_stripe.py --region global
 ```
 ![HadCRUT5 global warming stripe](plots/HadCRUT5-global-stripe.png)
 
+## hadcrut5_close.py — Script usage
+
+```
+usage: hadcrut5_close.py [-h] [-f OUTFILE] [-p PERIOD] [-r {global,northern,southern}] [-v]
+
+Parse and plot the approach of HadCRUT5 dataset to a threshold temperature v2025.1 (stable)
+Copyright (C) 2020-2025 Davide Madrisan <d.madrisan@proton.me>
+License: GNU General Public License v3.0
+
+options:
+  -h, --help            show this help message and exit
+  -f, --outfile OUTFILE
+                        name of the output PNG file
+  -p, --period PERIOD   show anomalies related to 1961-1990 (default), 1850-1900, or 1880-1920
+  -r, --region {global,northern,southern}
+                        select between Global (default), Northern, or Southern Temperatures
+  -v, --verbose         make the operation more talkative
+
+examples:
+  hadcrut5_close.py
+  hadcrut5_close.py --period "1850-1900" --region global
+  hadcrut5_close.py --period "1880-1920" --outfile "HadCRUT5-1880-1920-threshold.png"
+```
+
+Below is a generated plot image for global anomalies related to the period `1880-1920` with a threshold set to 1.5°C.
+```
+$ ./hadcrut5_close.py --period "1880-1920" --region global
+```
+![HadCRUT5 global warming close](plots/HadCRUT5-global-threshold-1880-1920.png)
+
 # License
 
 The Python code of this project is released under the [GPL-3.0 license](https://github.com/madrisan/HadCRUT5/blob/main/LICENSE).

hadcrut5_close.py

@@ -0,0 +1,132 @@
+#!/usr/bin/python3
+# Copyright (c) 2025 Davide Madrisan <d.madrisan@proton.me>
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+"""
+Plotting the approach of HadCRUT5 dataset to a threshold temperature.
+"""
+
+import argparse
+
+import matplotlib.pyplot as plt
+from matplotlib.ticker import MultipleLocator
+import numpy as np
+
+from hadcrut5lib import argparser, HadCRUT5
+
+
+def parse_args() -> argparse.Namespace:
+    """This function parses and return arguments passed in"""
+    descr = "Parse and plot the approach of HadCRUT5 dataset to a threshold temperature"
+    examples = [
+        "%(prog)s",
+        '%(prog)s --period "1850-1900" --region global',
+        '%(prog)s --period "1880-1920" --outfile "HadCRUT5-1880-1920-threshold.png"',
+    ]
+
+    parser = argparser(descr, examples)
+    parser.add_argument(
+        "-f",
+        "--outfile",
+        action="store",
+        dest="outfile",
+        help="name of the output PNG file",
+    )
+    parser.add_argument(
+        "-p",
+        "--period",
+        action="store",
+        dest="period",
+        default="1961-1990",
+        help="show anomalies related to 1961-1990 (default), 1850-1900, or 1880-1920",
+    )
+    parser.add_argument(
+        "-r",
+        "--region",
+        choices=["global", "northern", "southern"],
+        action="store",
+        dest="region",
+        default="global",
+        help="select between Global (default), Northern, or Southern Temperatures",
+    )
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        action="store_true",
+        dest="verbose",
+        help="make the operation more talkative",
+    )
+
+    return parser.parse_args()
+
+
+def plotline(hc5: HadCRUT5, region: str, outfile: str, threshold):
+    """
+    Create a plot for the specified period and arguments and diplay it or save
+    it to file if outfile is set
+    """
+    hc5.datasets_download()
+    hc5.datasets_load()
+    hc5.datasets_normalize()
+
+    years = hc5.dataset_years()
+    ylabel = f"Temperature Anomalies relative to {hc5.dataset_period}"
+
+    regions_switch = {
+        "global": hc5.GLOBAL_REGION,
+        "northern": hc5.NORTHERN_REGION,
+        "southern": hc5.SOUTHERN_REGION,
+    }
+    _, mean, _ = hc5.dataset_normalized_data(regions_switch[region])
+
+    _, ax = plt.subplots()
+    ax.set_frame_on(False)
+    ax.tick_params(axis="both", which="both", length=0)
+    ax.yaxis.set_major_formatter("{x:.1f}°C")
+    ax.yaxis.set_major_locator(MultipleLocator(0.5))
+
+    plt.hlines(
+        threshold,
+        np.min(years),
+        np.max(years),
+        colors="white",
+        linestyles="dotted",
+    )
+
+    ymin = min(mean)
+    plt.imshow(
+        np.linspace(0, 1, 256).reshape(-1, 1),
+        origin="lower",
+        aspect="auto",
+        cmap="coolwarm",
+        extent=(years[0], years[-1], ymin, 2.0),
+    )
+    plt.fill_between(years, ymin, mean, color="w")
+
+    plt.title(f"HadCRUT5: Closing in to {threshold}°C")
+    plt.xlabel("year", fontsize=10)
+    plt.ylabel(ylabel, fontsize=10)
+
+    plt.plot(years, mean, "steelblue", linewidth=2)
+
+    if outfile:
+        plt.savefig(outfile, transparent=False)
+    else:
+        plt.show()
+
+
+# pylint: disable=C0116
+def main():
+    args = parse_args()
+
+    regions = (args.region == "global", args.region == "northern", args.region == "southern")
+    hc5 = HadCRUT5(
+        period=args.period,
+        regions=regions,
+        verbose=args.verbose,
+    )
+
+    plotline(hc5, region=args.region, outfile=args.outfile, threshold=1.5)
+
+
+main()

hadcrut5lib.py

@@ -33,7 +33,7 @@ def copyleft(descr: str) -> str:
     """Print the Copyright message and License"""
     return (
         f"{descr} v{__version__} ({__status__})\n"
-        "{__copyright__} <{__email__}>\nLicense: {__license__}"
+        f"{__copyright__} <{__email__}>\nLicense: {__license__}"
     )
 
 

plots.sh

@@ -30,4 +30,10 @@ echo "creating stripe image ..."
     --region global \
     --outfile plots/HadCRUT5-global-stripe.png
 
+echo "creating plot closing in to 1.5°C ..."
+./hadcrut5_close.py \
+    --period "1880-1920" \
+    --region global \
+    --outfile plots/HadCRUT5-global-threshold-1880-1920.png
+
 echo "done."