What Are Greenhouse Gases?
Many chemical compounds found in the Earth’s atmosphere act
as “greenhouse gases.” These gases allow sunlight to
enter the atmosphere freely. When sunlight strikes the Earth’s
surface, some of it is re-radiated back towards space as infrared
radiation (heat). Greenhouse gases absorb this infrared radiation
and trap the heat in the atmosphere. Many gases exhibit these “greenhouse”
properties. Some of them occur in nature (water vapor, carbon dioxide,
methane, and nitrous oxide), while others are exclusively human
made (certain industrial gases).
Why Are Atmospheric Levels Increasing?
Levels of several important greenhouse gases have increased by about
25 percent since large-scale industrialization began around 150
years ago. During the past 20 years, about three-quarters of human-caused
emissions came from the burning of fossil fuels.
What Effect Do Greenhouse Gases Have
on Climate Change?
In computer-based models, rising concentrations of greenhouse gases
produce an increase in the average
surface temperature of the Earth over time. Rising temperatures
may, in turn, produce changes in precipitation patterns, storm severity,
and sea level commonly referred to as “climate change.”
Assessments by the Intergovernmental Panel on Climate Change (IPCC)
suggest that the Earth’s climate has warmed between 0.6 and
0.9 degrees Celsius over the past century and that human activity
affecting the atmosphere is “very likely” an important
How can you help?
America, communities are taking action to help reduce emissions.
From hybrid vehicle fleets in Charlotte, to green buildings in Austin
and homes powered with renewable energy in Seattle, local governments
are moving forward with innovative energy solutions that help to
curb climate warming, save taxpayers and business dollars, and create
Help us with
your own ideas as we make Chester County the best and greenest county