Mortgage rates are on a rough ride. In just over a month, they're up a full percentage point to around 7.5%, a three-year high. Buyers are pulling back in response, and September home sales look poised for a steep downturn.

How did this happen? Blame surging bond yields worldwide. Mortgage rates are particularly sensitive to the movements of the 10-year Treasury yield (^TNX), which has jumped to multiyear highs in recent weeks.

Read more: How to get the lowest mortgage rates right now

Unpacking what's moving bond yields higher so quickly is more complicated. Economists point to a web of factors causing investors to rewrite their expectations for inflation and economic growth.

"There's clearly a trend," said Daryl Fairweather, chief economist at Redfin. "There's something meaningful happening with us moving into a higher-for-longer economy."

While it's impossible to predict where bond yields and mortgage rates go from here, 8% loans now look like a not-so-distant possibility. Here's why experts told Yahoo Finance the current environment looks like one where rates could stay high, and even keep rising.

Oil prices and Iran

Mortgage rates jolted higher in the weeks after the US attacked Iran on Feb. 28 as investors fretted about rising oil prices and their implications for inflation. Although oil prices have fallen from their peaks, concern remains about how higher energy prices will reverberate across supply chains, potentially worsening inflation.

Apart from oil prices themselves, general uncertainty about the situation in Iran is also pushing rates higher, as investors want more compensation for unknown risks, said Jake Krimmel, senior economist at Realtor.com.

"The geopolitical uncertainty is a huge part of it," Krimmel said. "We're talking about supply shock. That doesn't just touch oil, but probably everything else with trade."

Meanwhile, Treasury Secretary Scott Bessent, who has tried to lower bond yields via buybacks to little effect, has blamed much of the rise in bond yields and mortgage rates on energy prices.

"I don't know if this conflict's going to end next week, next month, in two months, but I believe on the other side of this, energy prices will be much lower and interest rates, mortgage rates will come back down," he said on Monday .

Read more: How soaring Treasury yields could hit your finances

Economic growth

Still, few economists think energy prices alone explain today's higher rates, because the US economy has been showing the kind of growth that typically causes bond yields and mortgage rates to rise.