In an era where climate denial often hides behind the complexity of natural cycles, Dave Borlace delivers a rare, data-driven dismantling of the "Grand Solar Minimum" theory. He doesn't just dismiss the idea that the Sun is cooling our planet; he uses the very physics of solar irradiance to prove that even a historic solar dip would be a mere footnote against the roaring trend of human-induced warming. For busy readers trying to cut through the noise of weather chaos, this piece offers a crucial reality check: the Sun is not the villain, nor the savior, in our current climate crisis.
The Physics of the Sunspot
Borlace begins by grounding the reader in the sheer scale of our star, describing it as a "massive nuclear fusion reactor" that converts "about 600 million tons of hydrogen into helium" every single second. He meticulously traces the history of solar observation, from Galileo's telescope to the modern Wolf index, establishing that while the Sun does have an 11-year cycle of activity, the variations are minuscule. He explains that while sunspots and magnetic flips are fascinating, they result in a total solar irradiance variance of only "one point four watts per square meter."
This framing is effective because it forces the reader to confront the scale of the numbers. Borlace breaks down the math of radiative forcing, showing that after accounting for Earth's spherical shape and reflectivity, the actual energy change is a tiny "0.25 watts per square meter." He notes that this works out to "about zero point zero one eight percent" of the total energy hitting Earth. By isolating the solar variable so precisely, he strips away the mystique that often surrounds solar minimum theories.
"Blaming the Sun is a cop-out. We've caused climate change and we all need to change our lifestyles radically if we're to stand any chance at all of fixing the problem."
The Data vs. The Myth
The core of Borlace's argument rests on a direct comparison between solar activity and global temperature trends. He points out that while some cite the "Maunder Minimum"—a period of low sunspots from 1645 to 1715—as the cause of the "Little Ice Age," the timing doesn't actually align. He writes, "the onset of the Little Ice Age occurred between 1560 and 1600 at least 50 years before the beginning of the maunder minimum." Instead, he leans on paleoclimate data suggesting volcanic activity was the primary driver, not the Sun.
Borlace then pivots to the modern era, presenting a stark contradiction: "since 1970 global temperatures have shot up by almost nine point seven degrees Celsius while the amount of solar energy reaching the earth has actually declined." This divergence is the smoking gun. He cites a study by Geert Filner and Stefan Rahmstorf, which models a scenario where solar activity drops to Maunder Minimum levels today. The result? A temperature reduction of "no more than 0.3 degrees Celsius." This is a devastatingly small number in the context of current warming trends.
Critics of this view might argue that solar cycles have complex, non-linear effects on atmospheric circulation that simple irradiance charts miss. However, Borlace counters this by highlighting the distinct "fingerprint" of greenhouse gas warming: the upper atmosphere is cooling while the lower atmosphere warms, a pattern the Sun cannot produce. He emphasizes that the increase in extreme weather events is "entirely predictable and explainable within the context of human-induced global warming."
The Human Element
Ultimately, Borlace frames the solar minimum theory not just as a scientific error, but as a psychological escape hatch. He suggests that "it's understandably tempting to blame these chaotic weather patterns on the Sun" because it allows us to "delude ourselves that climate change has nothing to do with human beings." He argues that this narrative lets society off the hook, avoiding the "culpability" required to address the root causes: burning fossil fuels and unsustainable agriculture.
He contrasts the natural, slow-moving solar cycles with the unprecedented speed of current warming, stating that the rate of temperature increase is "completely unprecedented in our planet's history." By anchoring the discussion in human agency, he shifts the focus from an uncontrollable cosmic force to a solvable policy challenge. The administration and global bodies must focus on the actual drivers—carbon dioxide and other greenhouse gases—rather than chasing a solar ghost.
"The increase in these types of weather events is entirely predictable and explainable within the context of human-induced global warming."
Bottom Line
Borlace's strongest contribution is his ability to translate complex radiative forcing data into a clear, undeniable narrative: the Sun is not the driver of current climate change. The piece's greatest vulnerability is its assumption that the audience is willing to accept the uncomfortable responsibility that comes with this conclusion. However, the evidence is robust, and the verdict is clear—watch for continued attempts to conflate natural solar cycles with anthropogenic warming, but trust the data that shows the Sun is a bystander, not the cause.