If you are younger than 65 right now and live in a developed country, you have a problem. On the one hand, you know that your society is aging rapidly and that means that the dependency ratio (i.e. the number of working age people who have to finance pensioners) increases rapidly. This will either lead to a reduction in social society and pension benefits over time or to higher taxes on both the working age population and pensioners. Either way, your expected net income after taxes declines, and your lifestyle is increasingly threatened.
Joachim do you think that the effects of climate change on proximate regions will lead to a markedly different outcome than experienced in Japan? The Japanese are notoriously averse to immigration and as an island nation they have the luxury of vast seas to keep unwanted immigrants out. The US and Europe, on the other hand, are connected by land to continents which may be the source of large numbers of emigrants due to cities and regions becoming increasingly inhospitable due to climate change causing heightened water stress, agricultural degradation, prevalence of disease and hotter nights.
You have not even included the big one: automation! The declining opportunities will differ on function and industry but will all contribute to an even greater decrease in the ratio of available dependence.