Final answer:
By analyzing air bubbles in ice cores and other proxies like tree rings and plant stomata, scientists can track historical greenhouse gas levels. This data shows a significant rise in atmospheric CO2 levels since the Industrial Revolution, illustrating the impact of human activities.
Step-by-step explanation:
Tracking Greenhouse Gases from the Past
Scientists track greenhouse gases from 100-1000 years ago using various methods. A primary method is analyzing air bubbles trapped in ice cores from Greenland and Antarctica, which provide snapshots of atmospheric CO2 levels from up to 800,000 years ago. These records reveal fluctuations between 180-280 parts per million (ppm), with higher levels during warm interglacial periods. Other methods include examining the stomatal index of plant leaves, tree ring analyses for climatic changes, and studying past drivers of global climate change such as Milankovitch cycles. The culmination of these efforts shows a steady increase in atmospheric CO2 since the onset of the Industrial Revolution, further confirming human impact on greenhouse gas concentrations.
These historical data are graphically represented in numerous studies, including ones that show the correlation between CO2 levels and Earth’s temperature over millennia. By studying these graphs and the underlying data from various proxies, scientists have been able to conclude that the Earth's temperature rise is linked with the increasing concentration of greenhouse gases. This provides a vital understanding of the climate system and highlights the influence of human activities since industrialization. The graph showing the steep rise in carbon dioxide levels after the Industrial Revolution until present day serves as a strong visual indicator of human impact on the Earth's atmosphere.