Global Climate Change: Evidence and Causes Maureen Knabb 1 , Tim Lutz 2 , and Win Fairchild 1 Department of Biology 1 and Department of Geology 2 West Chester University
2 Q#1: Based on your current knowledge, which statement is closest to your thoughts about the scientific evidence for global climate change? A. There is no evidence; it’s a scare tactic promoted by environmentalists and some politicians. B. There is evidence for climate change, but no evidence that human activities are involved. C. There is some evidence that humans are having an effect on climate. D. The evidence is clear that humans are significantly affecting climate.
3 Q#2: Based on your current knowledge, which statement is closest to your thoughts about the consequences for humans of global climate change? A. The effects of climate change, if any, will be small compared to natural changes that have occurred before. B. The effects of climate change will be minor except in poor, less developed countries. C. Climate change will significantly affect many countries. D. The effects of climate change will be catastrophic around the world.
4 You are an intern working with a U.S. Senator who is required to make important decisions about legislation designed to limit the impacts of global climate change. Imagine that…
Your job is to help the Senator… Understand the science behind climate change. Appreciate the impact of global climate change. Assess the effects of human activities on global climate change. 5
6 Climate refers to time and space patterns of precipitation, temperature, and wind. For example, temperature and precipitation differ across the United States. What is climate?
7 Climate change occurs when the patterns change in time (e.g., winter months get warmer) and space (e.g., monsoon rains occur further south). Suppose winter in Pennsylvania began to look like winter in Florida? What is climate change?
8 • Climate changes naturally on a range of timescales, from decadal (10’s of years), centennial (100’s of years), millennial (1000’s of years), and longer (glacial cycles, e.g. Ice Ages). • Climate changes naturally on a range of spatial scales, from local and regional to global. Why is studying climate change a scientific challenge?
9 • Climate determines the type and location of human- managed ecosystems, such as agricultural farmlands. • Climate affects the weathering of rock, the type of soil that forms, and the rate of soil formation. Why should we be interested in climate change?
10 • Climate helps to determine the quantity and quality of water available for human use. • Climate determines the severity of droughts, storms, and floods. Why should we be interested in climate change?
11 Climate largely determines the nature and locations of biomes (major terrestrial ecosystems, defined based on their plant communities).