Chapters 1 - U.S. Fish and Wildlife Service

Refuge Resources
emitted to the atmosphere through natural processes, while others are created and emitted solely
through human activities. The emission of GHGs through the combustion of fossil fuels (i.e., fuels
containing carbon) in conjunction with other human activities, appears to be closely associated with
global warming (State of California Office of Planning and Research 2008). The USEPA and the
State of California identify the principal GHGs that enter the atmosphere because of human
activities as: carbon dioxide (CO 2), methane (CH 4), nitrous oxide (N 2O), and fluorinated gases (i.e.,
hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride). The most common GHG that
results from human activity is carbon dioxide, followed by methane, and nitrous oxide.
Carbon dioxide enters the atmosphere through the burning of fossil fuels. Methane is emitted
during the production and transport of coal, natural gas, and oil, and is also emitted as a result of
livestock and other agricultural practices and the decay of organic waste in municipal solid waste
landfills. Nitrous oxide is emitted during agricultural and industrial activities, as well as during
combustion of fossil fuels and solid waste. Fluorinated gases are synthetic, powerful greenhouse
gases that are emitted from a variety of industrial processes and are sometimes used as substitutes
for ozone-depleting substances.
California, where the Refuge is located, is a substantial contributor of GHGs, emitting over 400
million tons of carbon dioxide a year (California Energy Commission 2006). Climate studies
indicate that California is likely to see an increase of three to four degrees Fahrenheit over the
next century. As primary GHGs have a long lifetime in the atmosphere, accumulate over time, and
are generally well-mixed, their impact on the atmosphere is mostly independent of the point of
emission.
The impact of anthropogenic activities on global climate change is apparent in the observational
record. Air trapped by ice has been extracted from core samples taken from polar ice sheets to
determine the global atmospheric variation of carbon dioxide, methane, and nitrous oxide from
before the start of the industrialization (approximately 1750), to over 650,000 years ago. For that
period, it was found that carbon dioxide concentrations ranged from 180 ppm to 300 ppm. For the
period from approximately 1750 to the present, global carbon dioxide concentrations increased
from a pre-industrialization period concentration of 280 ppm to 379 ppm in 2005, with the 2005
value far exceeding the upper end of the pre-industrial period range (IPCC 2007). The IPCC
constructed several emission trajectories of GHGs needed to stabilize global temperatures and
climate change impacts and concluded that a stabilization of GHGs at 400 to 450 ppm carbon
dioxide-equivalent concentration is required to keep mean global climate change below 2°C (3.6°F).
To address GHG emissions at the Federal level, President Obama on October 5, 2009 signed
Executive Order 13514 on Federal Sustainability, setting measureable environmental performance
goals for Federal Agencies. Each Federal Agency was required to submit a 2020 GHG pollution
reduction target from its estimated 2008 baseline to the White House Council on Environmental
Quality and to the Director of the Office of Management and Budget by January 4, 2010. On
January 29, 2010, President Obama announced that the Federal Government will reduce its GHG
emissions by 28 percent by 2020. To achieve this goal, each Federal agency must develop a
“Sustainability Plan” that defines how sustainability goals will be met, energy use will be reduced,
long-term savings will be achieved, taxpayer dollars will be saved, and local clean energy jobs will
be created.
In California, to avert the consequences of climate change, California Assembly Bill 32 (AB 32), the
Global Warming Solutions Act of 2006, was signed into law in 2002. AB 32 establishes a state goal
of reducing GHG emissions to 1990 levels by the year 2020. It also directed the California Air
Resources Board (CARB) to begin developing discrete early actions to reduce greenhouse gases
Draft Comprehensive Conservation Plan/Environmental Assessment 4-33