Climate Change

Over the last two hundred years, human activities have altered the earth's atmospheric composition. In addition to the burning of fossil fuels, such as coal and oil, certain land use practices, like deforestation, have contributed to an increase in the amount of heat-trapping greenhouse gases in the atmosphere. Greenhouse gases, such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N20), and water vapor prevent heat from escaping into space, somewhat like the glass panels of a greenhouse. Scientists believe that the increasing concentrations of these gases in the atmosphere are raising Earth's temperature above historic levels.

The Greenhouse Effect

Global atmospheric concentrations of CO2, CH4 and N20 have increased markedly since 1750 and now far exceed pre-industrial values. Scientists have determined the historic levels of greenhouse gasses from bubbles trapped in ice cores that are thousands of years old. The global increases in CO2 concentrations are due primarily to fossil fuel use and land-use change.

According to NOAA and NASA data, the Earth's average surface temperature has increased on average by 1.2 to 1.4 °F in the last 100 years. Other aspects of the climate are also changing, such as rainfall patterns, snow and ice cover, and sea level. The accumulative effects of these changes are challenging traditional approaches to how people, industries, and governments manage and use the Earth's natural resources.

IPCC Findings

The key findings on global warming from the Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC) include:

• Warming of the climate system is unequivocal.
• Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely (~90%) due to the observed increase in anthropogenic (human) greenhouse gas concentrations.
• The amount of carbon dioxide in the atmosphere in 2005 (379 ppm) exceeds by far the natural range of the last 650,000 years (180 to 300 ppm).
• Eleven of the twelve years in the period 1995-2006 rank among the top 12 warmest years in the instrumental record (since 1850).
• Warming in the last 100 years has caused about a 0.74 °F increase in global average temperature.

Annual combustion of fossil fuels adds about 8 billion tons of carbon to the atmosphere. Many models predict that future annual emissions will be 16 billion tons, twice our current rate, by the year 2060. In order to stabilize CO2 output at current levels, projected future carbon emissions would need to be reduced by about 8 billion tons per year by 2060. There are a suite of available technologies for mitigating current CO2 emissions, but it is important to remember that no one tool will “solve” global climate change.

Strategies for change

Strategies for CO2 reductions include increasing transportation efficiency, increased efficiency of heating and electricity production, increased use of biofuels, nuclear energy, renewables such as wind and solar, carbon sequestration, and biostorage. A combination of multiple strategies will have to be implemented to curb CO2 output. Within our partnership we will be focusing mainly on geologic and terrestrial sequestration as a means of reducing CO2 emissions.

Sources:
International Panel for Climate Change (http://www.ipcc.ch/)
Carbon Mitigation Initiative (www.princeton.edu/~cmi/)