Signs of Climate Change

1 / 5
If left unaddressed, the current signs of climate change will progress into more devastating, permanent effects that will dramatically change our way of life.
If left unaddressed, the current signs of climate change will progress into more devastating, permanent effects that will dramatically change our way of life.
2 / 5
The long, steady line shows the relatively stable level of atmospheric carbon dioxide, which remained at around 285 parts per million (ppm) until humans began burning fossil fuels in the mid-19th century (short line).
The long, steady line shows the relatively stable level of atmospheric carbon dioxide, which remained at around 285 parts per million (ppm) until humans began burning fossil fuels in the mid-19th century (short line).
3 / 5
More frequent occurrences of extreme weather, such as last spring’s floods in Nashville, Tenn., are among the numerous signs of climate change.
More frequent occurrences of extreme weather, such as last spring’s floods in Nashville, Tenn., are among the numerous signs of climate change.
4 / 5
The famous Grinnell Glacier (in Glacier Nation Park, Mont.) has undergone a dramatic recession in recent years. The top photo, taken in 1940, shows the very beginnings of Upper Grinnell Lake in the bottom left corner of the glacier. The bottom photo, from 2004, shows hte expansion of the lake due to the melting of the glacier. As global warming continues, the park is expected to lose all of its namesake glaciers by 2030.
The famous Grinnell Glacier (in Glacier Nation Park, Mont.) has undergone a dramatic recession in recent years. The top photo, taken in 1940, shows the very beginnings of Upper Grinnell Lake in the bottom left corner of the glacier. The bottom photo, from 2004, shows hte expansion of the lake due to the melting of the glacier. As global warming continues, the park is expected to lose all of its namesake glaciers by 2030.
5 / 5
Shorter, milder winters have allowed pine beetles to expand their range, and new regions are experiencing major forest damage, such as California’s Easter Sierra Nevada mountains.
Shorter, milder winters have allowed pine beetles to expand their range, and new regions are experiencing major forest damage, such as California’s Easter Sierra Nevada mountains.

Our planet is undergoing dramatic changes right before our eyes. I am concerned about the connection these changes have with climate change, and I believe we can’t ignore the evidence or climate change science any longer. Misinformation and political debate surround this topic, despite consensus among respected scientific societies including the American Meteorological Society, the U.S. National Academy of Sciences and the Intergovernmental Panel on Climate Change (IPCC). To better understand the current phenomena and to better analyze climate-related headlines, let’s start by looking at the basic science of how our planet’s climate works.

Climate Change Science

The sun provides the solar radiation required for Earth to maintain a stable, life-supporting temperature. Solar radiation is cyclical; it stops at night. Earth’s atmosphere contains greenhouse gases (carbon dioxide, methane, nitrous oxide and water vapor), which help maintain the planet’s stable temperatures. These greenhouse gases cloak Earth like a blanket and allow shortwave radiation from the sun to pass through the atmosphere and warm the planet. They also absorb some of Earth’s outgoing radiation and then reradiate some of this absorbed energy — which would otherwise be sent into outer space — back to the Earth’s surface. Without the right mix of greenhouse gases, Earth would be too cold to support life.

Increased concentrations of greenhouse gases are now causing the planet to get warmer. This current warming is primarily the result of human actions, especially the release of carbon dioxide when humans burn carbon-based fossil fuels (coal, oil and natural gas). The extraction, processing and burning of fossil fuels has created an atmospheric overload of greenhouse gases.

Humans started using fossil fuels as an energy source during the Industrial Revolution. Before then, atmospheric levels of carbon dioxide were about 285 parts per million (ppm). In 2009, the level reached 390 ppm — substantially higher than any time in the past 800,000 years. (See the climate change chart in the Image Gallery.) Since 1850, Earth’s surface temperature has risen 1.3 degrees Fahrenheit, and the 20th century was warmer than any time period in the past 400 years.

  • Published on Jul 15, 2011
Comments (0) Join others in the discussion!
    Online Store Logo
    Need Help? Call 1-800-234-3368