FORTUNE - New data from OKCupid shows that climate denial, also referred to as "petromasculinity," was the biggest deal-breaker for dating app users. Of 250K users surveyed worldwide by OKCupid, 90% of users said it was important for their match to care about climate change. Over the past three years, 6M users have been surveyed, and results show that 81% of users were concerned about climate change.