The Basics
Beginning late in the 18th century, human activities associated with the Industrial Revolution has changed the composition of the atmosphere and therefore are influencing the Earth's climate.
Science
For over the past 200 years, the burning of fossil fuels, such as coal and oil, and deforestation have caused the concentrations of heat-trapping "greenhouse gases" to increase significantly in our atmosphere. These gases prevent heat from escaping to space, somewhat like the glass panels of a greenhouse.
Greenhouse gases are necessary to life as we know it, because they keep the planet's surface warmer than it otherwise would be. But, as the concentrations of these gases continue to increase in the atmosphere, the Earth's temperature is climbing above past levels. According to NOAA and NASA data, the Earth's average surface temperature has increased by about 1.2 to 1.4ºF in the last 100 years. Eleven of the last twelve years rank among the 12 warmest years on record (since 1850), with the warmest two years being 1998 and 2005. Most of the warming in recent decades is very likely the result of human activities. Other aspects of the climate are also changing such as rainfall patterns, snow and ice cover, and sea level.
If greenhouse gases continue to increase, climate models predict that the average temperature at the Earth's surface could increase from 3.2 to 7.2ºF above 1990 levels by the end of this century. Scientists are certain that human activities are changing the composition of the atmosphere, and that increasing the concentration of greenhouse gases will change the planet's climate. But they are not sure by how much it will change, at what rate it will change, or what the exact effects will be.
Greenhouse Gas Emissions
In the U.S., the energy-related activities account for three-quarters of our human-generated greenhouse gas emissions, mostly in the form of carbon dioxide emissions from burning fossil fuels. More than half the energy-related emissions come from large stationary sources such as power plants, while about a third comes from transportation. Industrial processes (such as the production of cement, steel, and aluminum), agriculture, forestry, other land use, and waste management are also important sources of greenhouse gas emissions in the United States.
Health and Environmental Effects
Climate change affects people, plants, and animals. Scientists are working to better understand future climate change and how the effects will vary by region and over time.
Scientists have observed that some changes are already occurring. Observed effects include sea level rise, shrinking glaciers, changes in the range and distribution of plants and animals, trees blooming earlier, lengthening of growing seasons, ice on rivers and lakes freezing later and breaking up earlier, and thawing of permafrost. Another key issue being studied is how societies and the Earth's environment will adapt to or cope with climate change.
In the United States, scientists believe that most areas will to continue to warm, although some will likely warm more than others. It remains very difficult to predict which parts of the country will become wetter or drier, but scientists generally expect increased precipitation and evaporation, and drier soil in the middle parts of the country. Northern regions such as Alaska are expected to experience the most warming. In fact, Alaska has been experiencing significant changes in climate in recent years that may be at least partly related to human caused global climate change.
Human health can be affected directly and indirectly by climate change in part through extreme periods of heat and cold, storms, and climate-sensitive diseases such as malaria, and smog episodes.
What You Can Do
Greenhouse gases are emitted as a result of the energy we use by driving and using electricity and through other activities that support our quality of life like growing food and raising livestock. Greenhouse gas emissions can be minimized through simple measures like changing light bulbs in your home and properly inflating your tires to improve your car's fuel economy. There are many steps that individuals can take to decrease greenhouse gas emissions and also save money. This and other websites
Don't Buy, Don't Drive, Don't Fly
There is one step, in particular, that always works and has a carbon weight of zero. Simply, whenever you can, don't buy, don't drive, don't fly. Every time you decide to not buy a product or service and put that money in the bank, you fund your retirement and don't produce a single gram of carbon emissions. If you walk or bike, instead of drive, again
zero emissions. If you use remote meeting tools to get your work done instead of flying to a destination, again almost zero emissions. When you purchase a used product, instead of buying new, again zero emissions. When you give a product to a friend, instead of that friend purchasing something new, again, zero emissions. Ok, the reality is that most places are not setup for zero driving. So 'shoppool', meaning go shopping with a friend. Carpool, which drops one car trip per person. Buy smart, higher quality, longer lasting products, instead of something that must be replaced every two years.
