OUR GLOBAL CHALLENGE
Climate Change is the defining issue of our time and we are at a defining moment.
Without drastic action today, adapting to these impacts in the future will be more difficult and costly.
The greatest threat humanity has ever faced
Climate activist Greta Thunberg explains why, in August 2018, she walked out of school and organized a strike to raise awareness of global warming, protesting outside the Swedish parliament and grabbing the world's attention. "The climate crisis has already been solved. We already have all the facts and solutions," Thunberg says. "All we have to do is to wake up and change."
"Scientific evidence for warming of the climate system is unequivocal"
Intergovernmental Panel on Climate Change
The planet's average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere. Most of the warming occurred in the past 35 years.
The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of more than 0.4 degrees Fahrenheit (-17 degrees Celsius) since 1969.
The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost an average of 286 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 127 billion tons of ice per year during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade.
Global sea level rose about 8 inches (0,2 meters) in the last century. The rate in the last two decades, however, is nearly double that of the last century and is accelerating slightly every year.
The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.
Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.