On July 11, 2026, Ivor Cummins, a biochemical engineer and prominent independent commentator, shared a video clip that he described as one "that should really be shared with every human on the planet." The post quickly gained traction, amassing thousands of likes, reposts, and views. The video clip features excerpts from a U.S. Senate Environment and Public Works Committee hearing, where Dr. David Denning, a geologist, testifies against attributing recent warming solely to human activity. Dr. Denning's testimony is from a 1995 *Science* journal study on North American warming trends, which he argues against attributing recent warming solely to human activity, pointing to historical natural variability. He criticizes efforts to "erase" or downplay the Medieval Warm Period (MWP), a time when temperatures were warmer than today in many regions, evidenced by Viking settlements in Greenland and expanded viticulture in England. This criticism is a significant challenge to the dominant climate narrative, which emphasizes the role of human activity in causing recent warming.

Key Facts and Background

Dr. David Denning's testimony is a decades-old critique of climate data bias, which has resurfaced in the context of the ongoing climate debate. The testimony is from a 1995 *Science* journal study on North American warming trends, which Denning argues against attributing recent warming solely to human activity. This perspective is in contrast to the dominant climate narrative, which emphasizes the role of human activity in causing recent warming. The video clip features excerpts from a U.S. Senate Environment and Public Works Committee hearing, where Denning testifies against the "hockey stick" graph, a 1999 reconstruction of paleoclimate data that depicts relatively stable temperatures for centuries followed by a sharp 20th-century rise. Denning and similar skeptics argue that the graph misrepresents paleoclimate data by minimizing the MWP and Little Ice Age (LIA), creating an exaggerated narrative of unprecedented modern warming.

The Medieval Warm Period and Little Ice Age

The Medieval Warm Period (MWP) was a time of relatively warm temperatures, roughly from 950-1250 AD, which is evidenced by Viking settlements in Greenland and expanded viticulture in England. This period is significant because it challenges the dominant climate narrative, which emphasizes the role of human activity in causing recent warming. The Little Ice Age (LIA), which occurred from approximately 1300-1850 AD, was one of the coldest periods in the last 10,000 years. Denning's testimony highlights the importance of considering natural climate variability, such as the MWP and LIA, in understanding current climate trends. He argues that efforts to downplay or erase these natural climate phenomena are a form of data bias, which can lead to an exaggerated narrative of unprecedented modern warming.

Reaction and Implications

The video clip has sparked a significant reaction, with many viewers expressing concern about the manipulation of climate data. The clip has also been shared widely on social media, with some users praising Cummins for sharing the testimony and others criticizing the content. The implications of Denning's testimony are significant, as they challenge the dominant climate narrative and suggest that natural climate variability may be a more important factor in understanding current climate trends. This perspective has important implications for climate policy and our understanding of the role of human activity in causing recent warming.

What Happens Next

The video clip has sparked a renewed debate about climate data bias and the role of natural climate variability in understanding current climate trends. It is unclear what will happen next, but it is likely that the debate will continue, with some arguing that Denning's testimony is a significant challenge to the dominant climate narrative and others dismissing it as a fringe perspective. The Rockefeller Foundation has committed over