We're now half way through the first decade of the 21st century, and I am finding it hard not a shake off an eerie sense that we are in times much akin the the first decade of the 20th.
I sense great changes are coming, changes that will seem obvious in hindsight, but are not clear today. The 1900s set in motion all the political and nationalist movements (communism, the arms build-up and division of Europe into the alliances that would lead to the carnage of World War One and all its horrendous consequences) that would dominate the 20th century. The importance of these changes was apparent to very few at the time.
I believe, personally, that global warming is going to be the most important factor, but I sense there are others that I am simply missing. Only an intuitive feeling without much substance, but it's there.