Global Warming Timeline 1880-2019
Arguments For Global Warming
Global Warming Dispute
Although some dispute that Carbon-dioxide emissions are related to global warming, the above timelapse clearly shows that the acceleration of Earth’s warming precisely match with the steep increase in CO2 emissions around the 50’s, 80’s and turn of the millenium in the graph below.
Carbon Dioxide Acts As The Earth's Thermostat
Carbon dioxide causes about 20 percent of Earth’s greenhouse effect; water vapor accounts for about 50 percent; and clouds account for 25 percent. The rest is caused by small particles (aerosols) and minor greenhouse gases like methane. Without greenhouse gases, Earth would be a frozen -18 degrees Celsius. With too many greenhouse gases, Earth would be like Venus, where the greenhouse atmosphere keeps temperatures around 400 degrees Celsius1Effects of changing the carbon cycle, NASA.
Water vapor concentrations in the air are controlled by Earth’s temperature. Warmer temperatures evaporate more water from the oceans, expand air masses, and lead to higher humidity. Cooling causes water vapor to condense and fall out as rain, sleet, or snow.
Carbon dioxide, on the other hand, remains a gas at a wider range of atmospheric temperatures than water. Carbon dioxide molecules provide the initial greenhouse heating needed to maintain water vapor concentrations. When carbon dioxide concentrations drop, Earth cools, some water vapor falls out of the atmosphere, and the greenhouse warming caused by water vapor drops. Likewise, when carbon dioxide concentrations rise, air temperatures go up, and more water vapor evaporates into the atmosphere—which then amplifies greenhouse heating.
So while carbon dioxide contributes less to the overall greenhouse effect than water vapor, scientists have found that carbon dioxide is the gas that sets the temperature. Carbon dioxide controls the amount of water vapor in the atmosphere and thus the size of the greenhouse effect.