*Volcanic Eruptions & Temperature The steady warming trend of recent decades has been temporarily interrupted three times by large volcanic eruptions. The red line is an average of climate model simulations for the 1900′s and demonstrates the models’ ability to replicate the temperature impact of large volcanic eruptions. IPCC http://climatecommunication.org/climate/natural-factors/
By injecting sulfate particles into the atmosphere, volcanic eruptions (blue spikes above) have had a temporary cooling influence on the planet. For example, the cooling influence of the 1991 Mt. Pinatubo eruption masked global warming for a few years. Similarly, some of the warming we would have otherwise experienced has been masked due to reflective sulfate particles (purple) produced by coal-fired power plants and wood smoke. The Sun’s output (orange) has varied slightly according to its 11-year cycle but has shown no upward trend. The warming effect of greenhouse gases (red) is by far the largest influence. It is also cumulative and long-lived; we are not yet experiencing the full warming influence of the greenhouse gases we have already put into the atmosphere. NASA/GISS *Warming & Cooling Forces
scienceagogo.com GLOBAL TEMPERATURES & CARBON DIOXIDE
*Carbon Emissions, CO2 Concentrations & Temperature Change http://climatecommunication.org/clima te/the-problem/
*Greenhouse Gas Concentrations Increases in concentrations of these gases since 1750 are due to human activities in the industrial era. Concentration units are parts per million (ppm) or parts per billion (ppb), indicating the number of molecules of the greenhouse gas per million or billion molecules of air.
wattsupwiththat.com Graph of CO2 (Green graph), temperature (Blue graph), and dust concentration (Red graph) measured from the Vostok, Antarctica ice core as reported by Petit et al., 1999. Higher dust levels are believed to be caused by cold, dry periods. TEMPERATURE & DUST LEVELS
capitalclimate.blogspot.com Global Surface Mean Temperature Land vs Ocean
South Cascade Glacier cumulative net mass balance set to zero at 1965 so that the three glacier records are more easily compared. Mass balance refers to the total amount of mass that a glacier has during a given year taking into account the amount lost to melting and the amount gained by new snowfall. Global Glacier Decline *GLACIAL MASS