> BUT, we've been building huge data centers for decades and they are minuscule compared to the size of the earth. My skeptic meter maxed out when i saw a Tesla with a "End Data Centers" bumper sticker on it. This is just the latest popular panic, isn't it?

Latest popular panic, yes, but also physical size relative to the whole planet isn't the relevant factor even for things which have very low power or energy densities like solar power and hydroelectric dams. Local impact on various resources (electricity, water for cooling, noise/thermal/particulate pollution between the compute and any on-site power supply) is somewhat more important.

  Five traverses at four facilities in the Phoenix, Arizona metropolitan area, ranging from a 36 MW single-building data center in Mesa to a 169 MW colocation campus in Chandler, reveal downwind air temperature warming as high as 2.2 °C, with average downwind air temperatures 0.7–0.9 °C warmer than corresponding upwind areas. Thermal signatures were detectable at distances up to 500 m from facility perimeters.

Being within a few hundred meters of a building that's consuming tens to hundreds of megawatts will do that, yes. I have no idea how big a normal factory would be to consume that much while running.