Global warming will cause abrupt rises in sea levels, deforestation, and flooding in less than 50 years, affecting over 2 billion people according to recent research. The research also suggests that the amount of rain and floods have been increasing in recent years due to long-term human-caused climate change. Additionally, the studies find that rainfall has become even more extreme since the mid-20th century, with the observed changes being too strong and rapid to be solely caused by natural causes.