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Dec 10 @ 2:00 pm EST – 4:00 pm EST
T for Track: Tracking Water Savings and Recognizing Success
WaterSense’s fourth and final technical training webinar of 2015 for commercial and industrial (C&I) facilities will help participants track ongoing water use to verify water savings from implemented projects and best practices. WaterSense will introduce[...]

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Climate Change: Background and Overview
Table of Contents
Background and Overview
Contributing Causes of Global Warming
Impacts of Global Warming
Reasons for Action
Climate Change Solutions
The Individual's Role
Where To Go for Help
Complete List of Links

Essential Links:

Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Chan...
Intended for managers and scientists working on air quality to provide information on the potential ...

Carbon Dioxide Capture and Storage
Report represents the formally agreed statement of the IPCC concerning current understanding of carb...

IPCC - The Fourth Assessment Report: Impacts, Adaptation and Vulnerability
Formally agreed statement of the IPCC concerning the sensitivity, adaptive capacity and vulnerabilit...

IPCC - The Fourth Assessment Report: The Mitigation of Climate Change
Focuses on the environmental, economic and social aspects of mitigation of climate change.

The Fourth Assessment Report: The Physical Science Basis
Describes fundamental earth science and the historical overview of climate change science.

US EPA - Inventory of Greenhouse Gas Emissions and Sinks
This report by U.S. EPA summarizes the latest information on U.S. anthropogenic greenhouse gas emiss...

What Is Climate Change?

Climate change is the long-term significant change in the patterns of average weather over an appropriate period of time. (The classical period of time is 30 years, as defined by the World Meteorological Organization [WMO]). Climate change may be caused by natural dynamic processes, external factors or "forcings" such as volcanic eruptions or solar variations, or by persistent human-caused (anthropogenic) changes in the composition of the atmosphere or in land use.

Some argue that the Earth's climate is cyclical and the current rise in temperatures is part of that natural cycle. In fact, prior to the dawn of the Industrial Age (pre-1750), changes in climate, or “forcings” were caused by such occurrences as changes in the shape of the Earth’s orbit, changes in the intensity of the sun, and volcanic eruptions.

Through human interference in the carbon cycle by activities such as burning crops, clearing forests, mining, and burning coal and other fossil fuels, we have moved carbon that was in a solid state to its gaseous state, thereby increasing atmospheric concentrations considerably. Since the onset of the Industrial Age, CO2 concentrations have become far greater, primarily from anthropogenic activities. In fact, CO2 levels over the last 400,000 years cycled relatively predictably in line with ice ages, but over the last 200 years, increased from around 280 ppm (parts per million) to more than 370 ppm today. These increases are projected to reach more than 560 ppm before the end of the 21st century.

According to the EPA, prior to the Industrial Era, the Medieval Climate Anomaly and the Little Ice Age defined the upper and lower boundaries of the Earth’s recent natural climate variability. Today, scientists on the Intergovernmental Panel on Climate Change (IPCC), the world's leading scientific and technical body for the assessment of climate change established in 1988 by the WMO and the United Nations Environment Programme (UNEP), acknowledge that human activities are responsible for most of the Earth's warming during the past 50 years.

While there are other greenhouse gases, CO2 is the primary greenhouse gas due to its sheer abundance in the atmosphere. There is a definitive correlation between the higher levels of CO2 and the rise of the earth’s temperature via the greenhouse effect.

What Causes Climate Change?

The Earth's atmosphere acts similar to a nursery greenhouse, allowing in the short wavelengths of visible light and of infrared wavelengths that are near the visible range from the sun. About 30 percent of the radiation is deflected when it hits the Earth's outer atmosphere, while 70 percent of the solar radiation is absorbed by the Earth's surface. The surface heats up and re-emits the energy as infrared radiation, resulting in higher temperatures. The infrared radiation is absorbed by clouds (water vapor) and GHGs(naturally occurring and anthropogenic)and is re-emitted both into space and back toward the ground. This causes the Earth's surface to warm even more, releasing more infrared radiation that is absorbed by GHGs and not allowed to escape back into the atmosphere.

To some degree, the greenhouse effect results in moderating the climate of the Earth so that it remains inhabitable. In fact, without GHGs, the Earth's surface is predicted to be around 60 degrees F (on average) colder than at present.

Current causes of climate change include some natural dynamic forces but currently, and more importantly, anthropogenic activities that emit GHGs. The most important GHGs with respect to climate impact, are carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. More than half the energy-related GHG emissions come from large stationary energy production sources including coal-fired power plants, while about a third come from transportation. Industrial and manufacturing processes (especially energy-intensive industries such as cement, steel, and aluminum production), along with agriculture, forestry, other land use, and waste management, are also important sources.


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The Climate Change Topic Hub™ was developed by:

Contact email: office@pprc.org

Hub Last Updated: 4/28/2015