Global interest rates are low and may head lower, driven by slowing economies and the U.S.-China trade war. A less appreciated reason for lower rates is a mountain of debt built up during the past decade.

Debt owed by governments, businesses and households around the globe is up nearly 50% since before the financial crisis to $246.6 trillion at the beginning of March, according to the Institute of International Finance, an association of global financial firms.

The borrowing helped pull economies out of the nasty recession, but left them with high debt burdens that make it harder for policy makers to raise rates. It also makes consumers and businesses more likely to pull back from spending money on new goods if economic conditions weaken.

“Globally, you are at worryingly high levels,” said Sonja Gibbs, managing director for global policy initiatives at the IIF. She said policy makers need to consider debt levels as they adjust interest rates. “There’s going to be an impact on the broader economy.”

In the U.K., Canada and Australia, central bankers have backtracked from rate increases in the past two years after consumers got bruised more than expected. U.S. consumers, who have borrowed to pay for college, cars and everyday spending, have been less affected because their debt burdens are much lower relative to their incomes.