Climate Change By the Numbers

Greenhouse Gases and Human Activity

Human activities cause the release of greenhouse gases
Carbon dioxide levels in the atmosphere are higher today than they have been in 800,000 years
Increases in the concentration of the greenhouse gases CO₂, methane, nitrous oxide, and halocarbons are attributable to human activity since industrialization
75% of human-driven CO₂ emissions come from the burning of fossil fuels for energy
33% of human-driven CO₂ emissions come from the transportation sector
Tropical deforestation accounts for 20% of global CO₂ emissions
The Arctic icecap is declining at a rate of 9% per year
The United States has one twentieth of the world's population, who release one fifth of the world's greenhouse gases
One third of all the CO₂ released by human activity since 1850 has been released by the United States
Americans release 20 tons of CO₂ per person per year, two times the European average and four times the global average
Coal burning power plants in the US release 2.5 billion tons of CO₂ per year, automobiles release 1.5 billion tons
The closest earth has come to the current CO₂ concentration during the past 400 millennia was 320,000 years ago, when the closest relatives to modern humans were the early Neanderthals, and even then CO₂ was only 300 ppm.

Global climate change will lead to more frequent and more severe extreme weather events such as hurricanes, droughts, heat waves, tropical storms, and flooding
A rise in sea level of 16 inches could put up 125 million people at risk for flooding
Land areas defined as "very dry" have doubled in extent since the 1970s
50% of the US population lives near the coast and is therefore vulnerable to sea level rise/ocean effects of climate change
Over 30,000 people were killed in the 2003 heat wave in Europe, which was the worst in 500 years
The Midwest has seen two severe floods of the intensity expected only once every hundred years, in the past 15 years
Category 4 and 5 storms have doubled in the past thirty years

Climate change could become the main driver of species extinction by the end of the century
An average increase of 2 degrees F will put up to 30 percent of the world's species at risk for extinction