Way back in the '70's, we were careening dangerously into the next Ice Age... until we weren't. Anyway, based on past patterns, we are due for a return to a colder climate but the margin for error is in the the thousands of years and we could have one or dozens of warm periods before it comes. Climate changes. Adapt.
If humanity is fated to disappear in 500 years, it will be because of mass hysteria.