Computer companies talk so much about “pipelines” that they sound like they’re in the oil and gas business. But they’re referring to the “pipeline” of graduates with computer science skills—a flow that, in recent years, has slowed to a trickle.

That’s the focus of this week’s Computer Science Education Week. It includes the “Hour of Code,” a program intended to ensure that tens of millions of students, of any age, learn how to program for at least an hour, through almost 200,000 events worldwide. The intention is to demystify code and show that anybody can learn the basics of programming.

“The goal of the Hour of Code is not to teach anybody to become an expert computer scientist in one hour,” the organization concedes. “One hour is only enough to learn that computer science is fun and creative, that it is accessible at all ages, for all students, regardless of background. The measure of success of this campaign is not in how much CS students learn—the success is reflected in broad participation across gender and ethnic and socioeconomic groups, and the resulting increase in enrollment and participation we see in CS courses at all grade levels.”

Why? Because more jobs require computer skills than ever. “Learning computer science also opens the door to high-demand jobs,” writes Phuong Le for the Associated Press. “By 2020, 4.6 million of 9.2 million science, technology, engineering and math jobs will be in computing, according to the U.S. Bureau of Labor Statistics.” “Jobs in computing are growing at twice the national rate of other types of jobs,” agrees Davey Alba in Wired. “By 2020, according to the Bureau of Labor Statistics, there will be 1 million more computer science-related jobs than graduating students qualified to fill them.”

Nonetheless, at the same time, there’s fewer opportunities for kids to study computer science. “Currently, computer science is taught in only about one of four high schools nationwide with fewer in lower middle and elementary school grades,” Le writes. “And only 27 states allow a computer science course to be counted toward graduation requirements in math or science, according to Code.org.”

This is particularly true in poor school districts and districts with large numbers of minorities, according to a recent survey by Google and Gallup. “If you’re Hispanic, Black, or from a lower-income household, your chances of having access to computers or CS learning opportunities are even slimmer” than those in average districts, writes Google in a blog post explaining the study. “Hispanic students are less likely than other groups to have access to computers with Internet at home and are less likely to use computers everyday at school; Black and low-income students are less likely than other groups to have access to CS at school; girls are less likely than boys to have learned CS.”

High schools wanting to teach computer science have three problems, Google writes:

Competing with the computer industry for people with skills to be teachers

Paying to properly outfit classrooms with the hardware, software, and connectivity they need to teach computer science

Needing to devote time to courses related to testing

Moreover, many schools that offer computer science education don’t include programming or coding in those classes, the survey found. “Nearly half of principals who say their schools offer computer science courses also state that computer programming/coding is not part of the coursework,” writes Gallup in the report, Searching for Computer Science: Access and Barriers in K-12 Education. “Of all principals surveyed, three in four report that they do not offer computer science with programming/coding. Only 21 percent of principals surveyed from schools that offer computer science classes say Advanced Placement (AP) computer science courses are available at their schools.”

This may be why, even in the high schools that do offer computer science programs, colleges don’t always give credit for those classes. They often aren’t counted as mathematics, let alone computer science, courses, and instead are considered “electives.” Consequently, fewer schools see the need to offer the classes, and fewer kids see the point in taking them, according to Claire Shorall, a computer science educator in Oakland, CA, who is circulating a Change.org petition to change this policy in the state.

In the good news department, there’s been a surge in interest in studying computer science in recent years, Le writes, noting that in 2015, nearly 49,000 students took the Advanced Placement exam in computer science, a 25 percent increase from the previous year. And a new AP computer science principles course—intended to increase representation among women and underrepresented minorities—debuts next fall, she adds. This is significant because students who had the opportunity to take an AP computer science exam were 46 percent more likely to indicate interest in a computer science major, Alba writes.

Even with these efforts, it may still take a while before the computer scientist pipeline is full. But at least the stream is showing signs of picking up momentum.