Here's a simple investment thesis: the future of artificial intelligence is really, really cold. And two massive investors are putting $4 billion behind that idea.

Equinix, the global data center colossus, and the Canada Pension Plan Investment Board (CPPIB), one of the world's largest pension funds, announced a joint agreement Friday to buy atNorth, a leading data center operator in the Nordic countries. They're buying it from private equity firm Partners Group (PGPHF) in a deal valued at roughly $4 billion, pending the usual regulatory nods and closing formalities.

To fund the purchase and future expansion, the partners have lined up a provisional financing package worth about $4.2 billion (or 3.6 billion euros, if you prefer).

Let's break down the ownership. CPP Investments is putting in roughly $1.6 billion for an estimated 60% controlling stake. Equinix will hold the remaining 40%. For Equinix, this isn't just a strategic move—it's a financial one they expect to pay off immediately, saying the acquisition should boost their adjusted funds from operations per share as soon as the deal closes.

So, what exactly are they buying? atNorth runs eight data centers spread across Denmark, Finland, Iceland, Norway, and Sweden, with more sites in the works. The company has secured about 1 gigawatt of power capacity—a massive amount of electricity—and has a pipeline of around 800 megawatts of capacity expected to come online over the next five years. Crucially for the AI boom, several of its facilities are already equipped with liquid cooling systems, which are essential for handling the intense heat generated by high-density AI and high-performance computing servers.

This brings us to the "why." Why the Nordics? The companies pointed to the region's potent combination of strong technical talent, resilient economies, abundant access to renewable energy (think hydro and geothermal), and, yes, that famously cool climate. Keeping thousands of power-hungry servers from overheating is a lot easier and cheaper when the outside air is cold.

"The scalable sites of atNorth are very complementary to Equinix's connectivity services and global footprint. Combined with our joint focus on sustainability, this acquisition is expected to enhance our ability to help customers unlock the full potential of the Nordics' expanding digital landscape," said Bruce Owen, President of EMEA for Equinix.

He added, "For businesses looking to scale with resilience, Equinix offers a future-ready infrastructure for long-term success, maintaining the jurisdictional and data sovereignty of organizations operating in the region."

From the seller's perspective, atNorth CEO Eyjólfur Magnús Kristinsson called the deal "a powerful validation of atNorth's journey and its market position as the leading Nordics data center platform." He noted it should enhance the company's access to capital and deepen relationships with hyperscale cloud customers. The company will continue to operate under the atNorth brand.

In early trading Friday, shares of Equinix were flat at $948.02.