Yes, I believe human accomplishments have long-term meaning. Humans created nuclear weapons and now we are living every day with the threat of catastrophic nuclear war. What humans have done to destroy the ozone layer has led to global warming and if steps are not taken to reverse carbon dioxide and other greenhouse gas emissions, there will be no future on earth.
There are of course positive human accomplishments as well. For example, advances in medicine and science have led to the eradication of many debilitating diseases. In addition today we have vaccines for infectious diseases like polio, smallpox, measles, rabies and flu.