Human action, however, has increased the presence of these gases in the atmosphere — mainly, carbon dioxide and methane —, causing them to retain more heat and to increase the temperature on the planet This is what we know as global warming HOW Today's atmosphere absorbs more than 3 watts of incoming solar energy over each square meter of Earth's surface According to NOAA's 19 Annual Greenhouse Gas Index (right axis), the combined heating influence of all major greenhouse gases has increased by 45% relative to 1990 Graph by NOAA Climategov based on data from NOAA ESRLAn increase in the atmospheric concentrations of greenhouse gases produces a positive climate forcing, or warming effect From 1990 to 19, the total warming effect from greenhouse gases added by humans to the Earth's atmosphere increased by 45 percent The warming effect associated with carbon dioxide alone increased by 36 percent
Greenhouse Effect Accessscience From Mcgraw Hill Education
