It is the increase in the temperature of the world.It has many effect.Some of the major effect include : Rise in tempreture, Glaciers melting, Ozone Layer depletion etc
Prediction in the Future
For the past 25 years, the generally accepted range for this potential warming has stood between 1.5 and 4.5°C. Which is a big range when you consider what a one-degree bump can do. Think 5 to 10 percent less rainfall during the dry season in the Mediterranean, southwest North America, and southern Africa. Reach 3°C of warming and Earth will lose 100,000 square miles of wetlands and drylands.
Some of the long-term effects of global climate change in the United States,according to the Third and Fourth National Climate Assessment Reports: