To understand the relative influence of each greenhouse gas, so-called forcing values (given in watts per square metre) calculated for the time period between 1750 and the present day are given below. Accessed March 2016. http://acdb-ext.gsfc.nasa.gov/Data_services/merged/index.html. A similar figure with many of these gases appears in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report.14 Satellite measurements of ozone were processed by the National Aeronautics and Space Administration and validated using ground-based measurements collected by the National Oceanic and Atmospheric Administration. Another process, the “biological pump,” involves the uptake of dissolved CO2 by marine vegetation and phytoplankton (small, free-floating, photosynthetic organisms) living in the upper ocean or by other marine organisms that use CO2 to build skeletons and other structures made of calcium carbonate (CaCO3). . Overall, this rate of accumulation has been linear (that is, uniform over time). The logarithmic relationship predicts that the surface warming potential will rise by roughly the same amount for each doubling of CO2 concentration. 2010. Ozone data have been averaged worldwide for each year to smooth out the regional and seasonal variations. Lüthi, D., M. Le Floch, B. Bereiter, T. Blunier, J.-M. Barnola, U. Siegenthaler, D. Raynaud, J. Jouzel, H. Fischer, K. Kawamura, and T.F. Historic CH4 records from Antarctic and Greenland ice cores, Antarctic firn data, and archived air samples from Cape Grim, Tasmania. Report 14 . In general, greenhouse gas concentrations have been particularly high during warm periods and low during cold periods. A number of oceanic processes also act as carbon sinks. CO2 has consequently accumulated in the atmosphere at an average rate of 1.4 parts per million (ppm) by volume per year between 1959 and 2006 and roughly 2.0 ppm per year between 2006 and 2018. Etheridge, D.M., L.P. Steele, R.L. Over time, these gases are removed from the atmosphere by chemical reactions or by emissions sinks, such as the oceans and vegetation, which absorb greenhouse gases from the atmosphere. Most ozone naturally exists in the layer of the atmosphere called the stratosphere, which ranges from approximately 6 to 30 miles above the Earth’s surface. What Does Stabilizing Greenhouse Gas Concentrations Mean? Carbon dioxide, methane, nitrous oxide, and certain manufactured gases called halogenated gases (gases that contain chlorine, fluorine, or bromine) become well mixed throughout the global atmosphere because of their relatively long lifetimes and because of transport by winds. Oak Ridge, TN: U.S. Department of Energy. This indicator also shows data from satellite instruments that measure ozone density in the troposphere, the stratosphere, and the “total column,” or all layers of the atmosphere. For carbon dioxide, methane, nitrous oxide, and halogenated gases, recent measurements come from monitoring stations around the world, while measurements of older air come from air bubbles trapped in layers of ice from Antarctica and Greenland. www.ncdc.noaa.gov/paleo/pubs/loulergue2008/loulergue2008.html. NOAA (National Oceanic and Atmospheric Administration). Rev. Greenhouse gases warm the planet. 2015. P. Natl. It focuses on the major greenhouse gases that result from human activities. Carbon dioxide (CO2) is the most significant greenhouse gas. Siple Station, Antarctica: approximately 1744 CE to 1953 CE Etheridge, D.M., L.P. Steele, R.J. Francey, and R.L. 2016. Greenhouse gases from human activities are the most significant driver of observed climate change since the mid-20 th century. Changes in stratospheric ozone reflect the effect of ozone-depleting substances. Antarctica: approximately 1903 CE to 1976 CE The warmer the surface, the greater the evaporation rate of water from the surface. For example, roughly 100 million years ago, during the Cretaceous Period, CO2 concentrations appear to have been several times higher than today (perhaps close to 2,000 ppm). Working Group I contribution to the IPCC Fifth Assessment Report. The annual average concentration of carbon dioxide (CO 2 ), the most significant anthropogenic greenhouse gas, increased to 405 and 408 parts per million (ppm) in 2017 and 2018, respectively. Harth, J. Mühle, A.J. IPCC (Intergovernmental Panel on Climate Change). Halocarbons and Other Atmospheric Trace Species group (HATS). 2001. As a result of human activities, however, these gases are entering the atmosphere more quickly than they are being removed, and thus their concentrations are increasing. Global atmospheric concentrations of carbon dioxide, methane, nitrous oxide, and certain manufactured greenhouse gases have all risen significantly over the last few hundred years (see Figures 1, 2, 3, and 4).