Global temperature trends

const width = 928;
const height = 600;
const marginTop = 20;
const marginRight = 30;
const marginBottom = 30;
const marginLeft = 40;

const x = d3.scaleUtc()
    .domain(d3.extent(data, (d) => d.date))
    .range([marginLeft, width - marginRight]);

const y = d3.scaleLinear()
    .domain(d3.extent(data, (d) => d.value)).nice()
    .range([height - marginBottom, marginTop]);

const max = d3.max(data, (d) => Math.abs(d.value));

// Create a symmetric diverging color scale.
const color = d3.scaleSequential()
    .domain([max, -max])
    .interpolator(d3.interpolateRdBu);

const svg = d3.create("svg")
    .attr("width", width)
    .attr("height", height)
    .attr("viewBox", [0, 0, width, height])
    .attr("style", "max-width: 100%; height: auto;");

svg.append("g")
    .attr("transform", `translate(0,${height - marginBottom})`)
    .call(d3.axisBottom(x).ticks(width / 80))
    .call((g) => g.select(".domain").remove());

svg.append("g")
    .attr("transform", `translate(${marginLeft},0)`)
    .call(d3.axisLeft(y).ticks(null, "+"))
    .call((g) => g.select(".domain").remove())
    .call((g) => g.selectAll(".tick line")
      .clone()
        .attr("x2", width - marginRight - marginLeft)
        .attr("stroke-opacity", (d) => d === 0 ? 1 : 0.1))
    .call((g) => g.append("text")
        .attr("fill", "#000")
        .attr("x", 5)
        .attr("y", marginTop)
        .attr("dy", "0.32em")
        .attr("text-anchor", "start")
        .attr("font-weight", "bold")
        .text("Anomaly (°C)"));

svg.append("g")
    .attr("stroke", "#000")
    .attr("stroke-opacity", 0.2)
  .selectAll()
  .data(data)
  .join("circle")
    .attr("cx", (d) => x(d.date))
    .attr("cy", (d) => y(d.value))
    .attr("fill", (d) => color(d.value))
    .attr("r", 2.5);

display(svg.node());

const data = [];
// https://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.csv
d3.csvParse(await FileAttachment("data/gistemp.csv").text(), (d, i, columns) => {
  for (let i = 1; i < 13; ++i) { // pivot longer
    data.push({date: new Date(Date.UTC(d.Year, i - 1, 1)), value: +d[columns[i]]});
  }
});
display(data);