A globally unprecedented crisis is facing China, thanks to the illegal but still-all-too-common practice of selectively aborting female fetuses. By 2020, China will find itself with 30 million more men of marrying age than women. What will this imbalance mean in practical terms? Here are five educated guesses:

1. A rise in imported mail-order brides

When Chinese men fail to find wives locally, they will likely look abroad. An early-1990s boy boom in South Korea has led to a similar imbalance, a sharp uptick in the number of "mixed" Korean marriages — 11 percent by 2008 — and a rise in "Kosian" (Korean-Asian) children.

2. An uptick in gay relationships

Homosexuality is not especially well-tolerated in China, but that could change as men — and society — run out of options, says Rudi Stettner in IndyPosted. Currently, it's believed that 90 percent of the estimated 25 million gay Chinese men marry women, often without confessing their sexual orientation, says University of Shanghai sexologist Liu Dalin, as quoted in The Economist. That option will dry up, and while lobbyist efforts to persuade Chinese legislators to approve gay marriage are making headway, it's slow going.

3. A kidnapping epidemic

Crime has doubled in China over the past 20 years, says The Florida Times-Union in an editorial, especially when it comes to "bride abductions and female trafficking." This problem may reach epidemic proportions when "scores of young men who [have] no prospects for marriage as a way of attaining a family or social status" come of age.

4. A real estate bubble

As women become scarce and harder to impress, men may be forced to attract mates with premium real estate, says Joe Weisenthal in The Business Insider, thus bidding up the market. The gender imbalance has already jacked up China's savings rate, says The Economist, as "parents with a single son save to increase his chances of attracting a wife."

5. A war to thin out excess men

Chinese officials are clearly worried about the gender imbalance, says Peter Hitchens in The Daily Mail, and if their current propoganda-based efforts to dissuade parents from killing or aborting female offspring don't work, "a war to cull the surplus males" is in the realm of possibilties. It's hard to say, because "nothing like this has ever happened to any civilization before."