Reference no: EM133704061
Exercise - Climate Trends
After completion of this lab, you will be able to:
Read and graph monthly average temperatures by decade from historical data sources;
Analyze trend lines in graphed data for change over time;
Interpret histograms; and
Understand the basis in data for modern climate change
Background
Atmospheric gases play a significant role in maintaining a global energy balance. They affect radiation from the sun on its way to the Earth's surface. Energy from the Sun comes as shortwave energy at the UV and visible end of the electromagnetic spectrum. Energy re-emitted from the Earth is much lower in temperature and longer wavelength. This is the basis for the greenhouse effect. Some of the re-emitted longwave radiation from the Earth is temporarily trapped within the atmosphere before it escapes back into space, resulting in heat retention.
The differing wavelengths between incoming solar radiation and outgoing radiation re-emitted by the Earth allow atmospheric gases to play specific roles in controlling the transmission of these wavelengths. For example, water vapour (H2O), absorbs mostly in the longwave end of the spectrum, blocking energy re-emitted from the Earth (Figure 1). In contrast, oxygen (O2) and ozone (O3), absorb mostly in the shortwave end of the spectrum (high-energy incoming solar radiation). This difference-where high-energy radiation is passed through the atmosphere, but lower energy radiation is prevented from escaping-allows for the greenhouse effect.
One of the first scientific stations to measure carbon dioxide (CO2) concentrations over long periods is still operational at Mauna Loa in Hawaii. The data recorded here have allowed us to track detailed changes in carbon dioxide concentrations over time. These concentrations are usually measured in ppm (parts per million) where 1 ppm CO2 represents 1 CO2 particle per million atmospheric particles.
Since initial measurements at Mauna Loa began, we have enhanced our understanding of global CO2 concentrations with more measuring stations and satellite measurements. This has allowed us to see a spatial distribution in CO2 emissions across the globe, and also better understand global energy budget.