People have been espousing that we are doomed for decades, but many of them were actually right: we have not meaningfully deviated from the predictions made by the 1972 report The Limits of Growth (https://en.wikipedia.org/wiki/The_Limits_to_Growth) for example. Reality has continued tracking along with our climate models, which were used to predict doom decades ago. Some doomsday scenarios have a preponderance of evidence that they are happening, and I feel that understanding that is not pessimism but realism.
