Although the reality of climate change has become a political issue, the scientific evidence argues it is real. Consider these points:

  • The change in the atmosphere – NASA data indicates that the levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 years. In 2013, carbon dioxide levels surpassed 400 ppm (i.e., parts per million) for the first time in recorded history, and it continues to rise. At levels above 550 ppm, the carbon dioxide will become harmful to humans
  •  Global temperature increase – NASA data shows an increase in global temperatures. Best scientific estimates suggest a rise of 1.4 degrees Fahrenheit (0.8 degrees Celsius) since 1880. Recent data indicates most of this warming has occurred since the 1970s
  • Sea level rise – EPA data, including satellite measurements, indicates a global sea level rise of 8 inches since 1880 due to melting ice at the polar caps and the thermal expansion of “warming oceans”
  • The warming oceans – NASA data indicates the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees Fahrenheit since 1969
  • Shrinking ice sheets – NASA’s data shows Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006. Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between 2002 and 2005
  • Declining Arctic sea ice – NASA data indicates that the Arctic sea ice has declined rapidly over the last several decades. In response, NASA has launched “Operation IceBridge” to image the Earth’s polar ice and understand processes that connect the polar regions with the global climate system
  • Glacial retreat – factually, glaciers are retreating around the world, including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa
  • Extreme events – According to the EPA the number of record high temperature events has been increasing, while the number of record low temperature events has been decreasing, since 1950. Concurrently, intense rainfall events are increasing
  • Ocean acidification – According to the National Oceanic and Atmospheric Administration (NOAA), acidity of surface ocean waters has increased by about 30 percent since the Industrial Revolution. This increase results from the amount of carbon dioxide absorbed by the upper layer of the oceans, which is increasing by about 2 billion tons per year
  • Decreased snow cover – NASA satellites reveal that the spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier

The preponderance of scientific evidence suggests that the climate is trending toward catastrophic change. This leads to an important question, “Why?” I’ll address “Why?” in my next post.