Reminder: How Earth’s Temperature is Changing

What's important:  the last decade was the warmest on record for over a century of global atmospheric and oceanic temperatures and each of the 10 warmest years recorded since 1880 have occurred in the last fifteen years.

So, drawing a comparison, how does human activity resulting in greenhouse gas emissions and global warming compare to the emission of volcanoes and the energy of nuclear warheads?

Comparing Global Warming to Volcanoes:

Human activity is by far the largest contributor to the observed increase in atmospheric CO2. Global CO2 levels have risen from 280 ppm prior to the Industrial Revolution to over 390 ppm today. According to the U.S. Geological Survey, human CO2 emissions amount to about 30 billion tons annually—more than 130 times as much as volcanoes produce each year. A case in point, In 1991 Mt. Pinatubo, one of the largest volcanic eruptions of the 20th century was estimated to have emitted 42 million tonnes of CO2. Globally, according to the US Energy Information Administration, human activity contributed 29,195 million tonnes of CO2 to the air in just 2006 alone- nearly 700 times as much as the Pinatubo volcanic eruption.

Comparing Global Warming to Nuclear Warheads:

A portion of the incoming solar radiation from the sun is trapped by greenhouse gases (ie, CO2, CH4, etc) in the earth’s atmosphere and the resulting heat energy absorbed by the oceans constitutes 80-90% of the total heat energy in the earth’s overall climatic system. The upper layers in the global oceans have warmed considerably over the last 15 years and the 2010 hurricane outlook is a dire reflection of this; the U.S. National Oceanic and Atmospheric Administration (NOAA) forecasted an “active to extremely active” hurricane season for 2010. The NOAA projected a 70 percent probability for 14 to 23 named storms, 8 to 14 hurricanes, and 3 to 7 major hurricanes. According to an oceanography study at the University of Hawaii's Joint Institute for Marine and Atmospheric Research, between 1993 and 2008 the upper 700 meters of the earth’s oceans absorbed about 0.6 watts per square meter of energy. That is nearly equivalent to the energy of 2 billion copies of the nuclear bomb that the United States dropped on Hiroshima during World War II.

The change in earth's temperature is important.

Sources:

http://www.nasa.gov/home/hqnews/2010/jan/HQ_10-017_Warmest_temps.html
http://www.noaanews.noaa.gov/stories2010/20100615_globalstats_sup.html
http://www.noaanews.noaa.gov/stories2009/20090916_globalstats.html
http://www.scientificamerican.com/article.cfm?id=seven-answers-to-climate-contrarian-nonsense
http://www.abc.net.au/environment/articles/2010/04/16//2874939.htm
http://www.nytimes.com/cwire/2010/05/20/20climatewire-robot-floats-record-sharp-increase-in-upper-67924.html