No, Bloomberg, One Chart Does Not Prove the World Is Getting Hot Fast

In a recent column titled “A Chart Climate Denialists Can’t Ignore,” Bloomberg writer Mark Gongloff presents a graph from Berkeley Earth’s Zeke Hausfather as proof that “the world is getting hotter, and fast.” While the chart may accurately display data, it is highly misleading because it doesn’t take the root causes of such temperature records into account, such as the Urban Heat Island (UHI) effect and the warm-biased placement of weather stations that record temperatures, factors that have nothing to do with climate change.

The chart, Gongloff claims, shows that nearly 80 percent of global land areas have experienced record monthly high temperatures in this century alone. From this, readers are told that the evidence is overwhelming and that skepticism about catastrophic climate change is “denial.” It’s a tidy narrative—but like many tidy narratives, it unravels when context and historical data are brought to bear.

The idea that today’s heat is “unprecedented” is simply false. In fact, most all-time state high temperature records in the United States were set long before the 21st century began. As detailed in Climate at a Glance: The Facts on Climate Change (2nd Edition, 2025), “the all-time high temperature records set in most states occurred in the first half of the twentieth century, decades before anyone was talking about human-caused climate change.” This is not a small technicality. It is a direct contradiction of the claim that modern warming is without historical parallel.

The 1930s remain the standout decade for heat in the American record. Data, drawn from the National Oceanic and Atmospheric Administration’s (NOAA) U.S. Historical Climatology Network, show that both the number and intensity of heatwaves peaked during that period. The Environmental Protection Agency (EPA) Heat Wave Index, cited in Climate at a Glance, confirms that the 1930s still dominate in frequency and duration of heatwaves nationwide. A chart from Our World in Data, shown below, verifies the EPA heatwave data:

More recently, the U.S. Climate Reference Network (USCRN)—a pristine system of modern sensors launched in 2005 to avoid problems like urban heat contamination—shows no sustained increase in high-temperature extremes since its inception, seen in Figure 2 below:

This data matters because the United States has the longest, most carefully maintained temperature record in the world. If there were truly a runaway increase in record heat, it would be evident here first. Instead, as The Heartland Institute notes, “there has been no significant warming across the United States since 2005” and “recent warming rates are no higher than in the early 20th century.” The NOAA record confirms this trend: when adjustments and urban heat biases are stripped away, the upward slope of U.S. maximum temperatures largely disappears.

Finally, a chart of high temperature records for the past century, seen below in Figure 3, easily disproves the Bloomberg claim.

What is too often ignored in mainstream reporting is the extent to which temperature datasets have been massaged over the years. Historical temperatures in the far past are routinely adjusted downward, and station siting biases in the present exacerbate the problem, exaggerating the appearance of a steep warming trend. An independent audit of the U.S. surface station network done by Heartland in 2022 found that well over 90 percent of stations fail NOAA’s own siting standards, with many positioned near heat sources such as buildings, parking lots, or air-conditioning exhausts. When only well-sited, rural stations are considered, the long-term warming trend falls dramatically.

This important context is missing entirely from Gongloff’s piece. Instead, readers are presented with an appealing graphic and a few cherry-picked statistics that appear to seal the case. Yet, as the new Climate at a Glance book points out, climate models and global averages often obscure more than they reveal. “Models run too hot,” the book notes, “and they consistently project more warming than is observed in the real world.” The gap between modeled projections and measured outcomes has persisted for decades, which raises questions not about “denial,” but about scientific humility.

In the United States, there has been no statistically significant increase in either the number or intensity of heatwaves since the early 20th century. That is not a matter of ideology—it is a matter of record.

Gongloff closes his piece by warning that the 1930s Dust Bowl may soon “seem like a cool interlude.” That is preposterous – the data tells a completely different story. America’s hottest decade remains the 1930s, and despite rising carbon dioxide emissions, modern heat extremes have not surpassed those early records. Before accepting graphics designed to shock, it’s worth remembering that charts can be constructed to emphasize whatever conclusion the author prefers. History, on the other hand, does not bend so easily.

Ultimately, long-term unbiased data and a proper accounting of the UHI effect destroy Bloomberg’s intentionally alarming claims about a rapidly warming world.