Scientists estimated global average carbon dioxide concentration at 397.2 parts per million (ppm) in 2014, as the global growth rate of carbon dioxide continues to accelerate. 

Charles Keeling's measurements of carbon dioxide from the summit of Mauna Loa have become a landmark for mankind’s impact on the Earth. In this video, NOAA scientists talk about the history of the observations that allow us to connect Earth's warming climate to the greenhouse gases from burning fossil fuels.

Friday, January 24, 2014

Concentration of carbon dioxide is about 1.4 times what it was before the Industrial Revolution. How much and how fast will Earth warm if carbon dioxide concentrations double the pre-industrial?


It is virtually certain our world will continue to warm over this century and beyond. The exact amount of warming that will occur in the coming century depends largely on the energy choices that we make now and in the next few decades.

As of 2013, the warming effect of long-lived greenhouse gases in Earth's atmosphere has increased by approximately 34% since 1990.

Human activities, mainly burning fossil fuels, are increasing the concentration of carbon dioxide in our atmosphere, amplifying the natural greenhouse effect.

Limiting the Magnitude of Climate Change

Meeting internationally discussed targets for limiting atmospheric greenhouse gas concentrations and associated increases in global average temperatures will require a major departure from business as usual in how the world uses and produces energy. This report from the America’s Climate Choices suite of studies recommends that a U.S. policy goal be stated in terms of a budget for cumulative greenhouse gas emissions over the period 2012 to 2050.