HOUSTON — A surge of oil production is coming, whether the world needs it or not.

The flood of crude will arrive even as concerns about climate change are growing and worldwide oil demand is slowing. And it is not coming from the usual producers, but from Brazil, Canada, Norway and Guyana — countries that are either not known for oil or whose production has been lackluster in recent years.

This looming new supply may be a key reason Saudi Arabia’s giant oil producer, Aramco, pushed ahead on Sunday with plans for what could be the world’s largest initial stock offering ever.

Together, the four countries stand to add nearly a million barrels a day to the market in 2020 and nearly a million more in 2021, on top of the current world crude output of 80 million barrels a day. That boost in production, along with global efforts to lower emissions, will almost certainly push oil prices down.

Lower prices could prove damaging for Aramco and many other oil companies, reducing profits and limiting new exploration and drilling, while also reshaping the politics of the nations that rely on oil income.