Global warming is real according to three key points: average global temperatures have increased 1.4 degrees since 1880 with the hottest periods in the last 400 years occurring in the last two decades; Arctic regions are experiencing disproportionate warming with ice rapidly disappearing and potentially ice-free summers by 2040; and human activities like burning fossil fuels are the main cause, releasing greenhouse gases and raising Earth's temperature 1 degree Fahrenheit in the past century.