Studies published in peer-reviewed scientific journals state that upward of 97 percent of actively publishing climate scientists agree that the climate is changing, likely due in part to human activity. Many prominent scientific organizations, such as the American Meteorological Society, The Geological Society of America and the American Physical Society, have published statements indicating that they too agree that climate change is real and largely man-made.
The Intergovernmental Panel on Climate Change published its Fifth Assessment Report in 2014 and found that each of the past three decades has been warmer than the preceding decade, and the hottest of any decades on record. The report also found that sea levels are rising, the ice caps are melting and storms and heat waves are intensifying. The report made clear that human activity, mainly emissions of greenhouse gases such as carbon and methane, is driving most of these changes and cautioned that by the end of the decade, the earth could experience an additional 3.7 to 4.8 degrees Celsius of warming at the current rate of emissions.
Since measurements began in 1880, the Earth’s average surface temperature has increased by an average of 1.4 degrees Fahrenheit, according to data from both NASA and the National Oceanic and Atmospheric Administration. The majority of this increase occurred in the same time frame indicated in the Intergovernmental Panel on Climate Change's 2014 publication. 2014 was the hottest year ever recorded, according to NASA scientists.