Climate change, or "global warming" in my opinion.
People aren't taking the steps needed to at least slow down the effects. While this is more long term, effects are definitely seen today. Among suffering plant and animal species, some land is being lost due to rising sea levels. Some places in the future could be uninhabitable due to the rising temperatures, even some cities in the next 10 or so years. But those numbers are definitely not able to be predicted 100%.
https://climate.nasa.gov/effects/
https://www.google.com/amp/miami.cbs...r-by-2025/amp/