1. What are climate change indicators and why are they useful? They are indicators that help us understand observed long-term trends related to the causes and effects of climate change. They include greenhouse gasses, weather and climate, oceans, snow and ice, health and society, and ecosystems.
2. What are the two largest sources of greenhouse gas emissions in the US? Electricity generation is the largest U.S. emissions source, accounting for 32 percent of total greenhouse gas emission. Transportation is the second-largest source of greenhouse gas emissions, accounting for 27% of total greenhouse gas emission.
3. How do current carbon dioxide concentrations in the atmosphere compare to concentrations in the past 100 years? 500,000 years? They are unprecedented and higher than any levels recorded since the beginning of the industrial era. Almost all of this increase is attributable to human activities. They are compared with the past 800,000 years.
4. What is meant by the term climate forcings? Does an increase in forcings cause cooling or warming? It refers to a change in the Earth's energy balance, leading to either a warming or cooling effect. An increase in the atmospheric concentrations of greenhouse gases produces a warming effect.
5. How much have temperatures changed in Tennessee in the last 100 years? Which areas of the US have experienced the most temperature change and by how much have the temperatures changed in these areas? Unusually hot days are becoming less common and decreased by 15-25% and unusually cold days are becoming less common and decreasing by 5-15%.
6. Which decade showed the most severe heat waves in US history? What is expected with the pattern of record high and record low temperatures. What has been observed in the last few decades?[NOTE: You will have to look at the “Learn More” section to answer this question correctly!] 2001-2010 was the warmest decade. Being that 2012 was the warmest year on record, it looks like the...