CHANGES IN THE CLIMATE SYSTEM

All major climate changes, including natural ones, are disruptive. Past climate changes led to extinction of many species, population migrations, and pronounced changes in the land surface and ocean circulation. The speed of the current climate change is faster than most of the past events, making it more difficult for human societies and the natural world to adapt. The evidence for rapid climate change is compelling:

CLIMATE CHANGE IS A MAJOR THREAT TO AGRICULTURE. 

Where, how and when we grow food is vitally connected to our climate's normal patterns. Worldwide, farmers are struggling to keep up with shifting weather patterns and increasingly unpredictable water supplies. Farms are more likely to face attacks from weeds, diseases and pests, which reduce yield.

GLOBAL TEMPERATURE RISE

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, with the five warmest years on record taking place since 2010.

OCEAN ACIDIFICATION

Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. 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.

WARMING OCEANS

The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees Fahrenheit since 1969.

EXTREME EVENTS (INFRASTRUCTURE AND TRANSPORTATION ARE AT RISK)

Hot weather, flooding and other extreme weather events damage infrastructure, put heavy burdens on electrical supplies and disrupt how we travel and commute. In Africa, we have also witnessed increasing numbers of intense rainfall events.

SEA LEVEL RISE

Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century.