Is AI Spending Too Big—or Is Earth's Economy Just Too Small? Elon Musk Picks a Side

Tesla and SpaceX CEO Elon Musk says Earth’s entire economy is less than a trillionth the size of a star-powered “K2 economy.” He made the remark while reposting a chart comparing AI infrastructure spending with America’s biggest infrastructure booms.

The chart sets projected AI outlays through 2032 against actual spending from past eras. On those estimates, AI is on pace to outstrip railroads, highways, and telecom. Musk, however, pointed to a far bigger yardstick.

AI Infrastructure Spending Is Set to Top Every Past Boom

A venture investor shared the chart on X with a one-word caption, “Epic.” It tracks average annual US infrastructure spending as a share of gross domestic product (GDP).

An Earth economy is less than a trillionth the size of a K2 economy https://t.co/CiVPMCuGf3

— Elon Musk (@elonmusk) September 24, 2026

According to the chart, AI outlays should average 3.63% of GDP between 2025 and 2032. By comparison, railroads averaged 2.24% from 1870 to 1890. Highways reached 1.13%, while telecom and fiber hit 1.1% around the dot-com era. Meanwhile, canals and electrification trailed at 0.66% and 0.5%.

The data credits Stijn Van Nieuwerburgh, a real estate professor at Columbia Business School. His research puts the total buildout near $8.2 trillion across data centers, power, and IT equipment.

He also warns that losses could spread to pension funds and other lenders if enthusiasm fades. Other skeptics point to circular Big Tech funding deals. Billionaire investor Ray Dalio has issued an AI bubble liquidity warning as well.

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Why Musk Measures Economies in Stars

The “K2” reference points to the Kardashev scale, a framework that ranks civilizations by energy use. A Type II civilization would harness nearly all the power its star produces.

Musk has made this case before. He has argued that SpaceX could outvalue Earth by tapping far more solar energy than humanity uses today. Therefore, space-based industry could eventually dwarf the current economy, in his view.

His nearer-term plans are more modest. In June, he outlined a path to quadrillionaire status that relies on factories on the Moon and Mars. Such outposts would still fall far short of capturing the Sun’s full output.

For now, investors face a nearer question. Can returns justify AI infrastructure spending on a scale set to top the railroad era?