Ten Points About Global Climate Change
March 2, 2007
On March 2, 2007, Dr. Patrick Minnis, a senior research scientist for NASA Langley Research Center Science Directorate, presented "Climate Change: An Uncertain Future," which contained the following excerpts:
- Climate is determined by weather, but you can't judge climate by weather. Weather is determined by the solar radiation and its distribution on the earth.
- In order to change the climate, you have to change something in the system. The two basic categories of causes of climatic change are: external, or extra-planetary changes that involve solar radiation; and internal, or changes inside the system resulting from such things as volcanic eruptions, snow and ice, aircraft contrails and greenhouse gases.
- The relationship between Earth's temperature record and carbon dioxide concentrations is complicated. Records do show that more carbon dioxide corresponds to warmer temperatures, but changes in CO 2 levels actually lag temperatures by 800 years. So there is not proof either way of CO 2 causing or not causing global warming.
- There is some indication that cloud cover may be decreasing, which would suggest changes to the "brightness of the earth." This brightness is called the albedo, which refers to the fraction of incoming radiation reflected back to space.
- According to the latest climate models, given the current composition of the atmosphere, we could see an increase in global surface temperature of 3.5 degrees Celsius and a 0.2-0.6 meter rise (15-25 inches) in mean sea level by 2100.
- Other climate changes expected to occur include changes in temperature circulation patterns, with most geographic areas getting warmer and very few getting cooler.
- Some coastal areas will disappear, with drier areas turning into marshlands, and tropical conditions may move toward the poles and up mountainsides.
- There will be new areas opening for agriculture, while other areas will no longer be productive. This has happened all along in the history of mankind, but not at the scale we're expecting to see in the future.
- Many species will change because of the increased CO 2 levels and warmer temperatures.
- It appears human activity is the best explanation for global warming. Conservation and the increased use of renewable energy so that we reduce the use of coal and oil will be key concerns.