Several other sources, the world is nearly one degree warmer than it was before the 1900s. The global average temperature for the first 10 months of 2018 was 0.98C above the levels of 1850-1900. Being one degree warmer might not sound like a problem, but if no action is taken, the world may experience a number of catastrophic events. For example, sea levels will rise and the ability to grow crops may be endangered.