Five Facts on Climate Change

The nature, pace and causes of climate change (of which global warming is a part) have been the subject of research and debate for many years, but the clear scientific consensus is now that climate change is happening, and that human activities are the cause.  Further, there are disturbing signs that climate change is happening rapidly, especially with the melting of polar ice. Learning Life offers the following five facts to help better understand the pace and severity of this global threat.

1) 97%

The percentage of climate scientists worldwide who agree that the climate warming trend is very likely due to human activities. Nearly 200 scientific organizations worldwide have come to this conclusion, including the Intergovernmental Panel on Climate Change, NASA Goddard Institute for Space Studies, Amazon Environmental Research Institute, European Science Foundation, and the Japanese Meteorological Agency.

2) 9 out of 10 of the warmest years since the year 2000

Since climate temperature recording began in 1880, 9 of the 10 warmest years have occurred in the 21st century, including 2013.  Each of the last three decades has been warmer than the last, and the current warming is unprecedented in the last 1,300 years, as ice cores and other historical evidence show.


3) 1,141 lives and $175 billion

The number of lives lost and the total economic cost of weather-related disasters caused by climate change in the United States over just the past two years. These costs are from 25 separate climate- and weather-related disasters.  Note: While any given weather disaster may not be due to climate change, climate change may have increased the number and severity of weather disasters.

4) 6.6 feet

The maximum level scientists expect the sea level to rise by the year 2100. Sea levels have been rising for decades.  Climate scientists are 90% certain that sea levels by this time will rise a minimum of 8 inches and a maximum of 6.6 feet.  In the U.S. alone, over eight million people live on coasts at risk of flooding. The 8-inch minimum is based on past sea level rising rates. The 6.6 feet maximum is based on ocean warming and “maximum plausible” loss of polar ice sheets and glaciers.

5) 400 parts per million (ppm)

The highest concentration of carbon dioxide (CO2) in the atmosphere in the last 800,000 years, according to data gathered from studying ice core records. That record reading was taken at the Mauna Loa Observatory in Hawaii on May 9, 2013, and matched readings from other sites in the Northern Hemisphere that year.

Carbon dioxide in Earth’s atmosphere contributes to global warming. Before the Industrial Revolution began in the mid-1700s, CO2 in the atmosphere is estimated to have been about 280 ppm, and had never exceeded 300 ppm in 800,000 years, until the early 20th century.  The excess 120 ppm trap up to 1.88 watts of energy per square meter of the Earth’s surface. This equates to 23 billion megawatts of energy trapped in the atmosphere every day, the same amount of energy produced in the United States in all of 2013.  As the U.S. Government’s website notes, “we are in uncharted territory.”