Final answer:
The period during which the total amount of nitrogen released most rapidly increased is the past 200 years, driven by industrialization, the combustion of fossil fuels, and the use of synthetic nitrogen fertilizers.
Step-by-step explanation:
The total amount of nitrogen released by human activities has increased most rapidly during the past 200 years, particularly with the onset of the industrial revolution. This significant growth can be attributed to two main factors: combustion of fossil fuels and use of synthetic nitrogen fertilizers in agriculture. Industrial processes, transportation, and agricultural practices have led to a rapid increase in the emissions of nitrogen oxides (NOx) and nitrous oxide (N₂O), which contribute to greenhouse gas effects and eutrophication of aquatic environments.
Moreover, the artificial fertilizers increase the bioavailability of nitrogen, boosting agricultural productivity but also causing eutrophication and contributing to climate change. Since the industrial revolution, human activities such as deforestation and fossil fuel combustion have also led to an increase in the concentration of greenhouse gases like CO₂ in the atmosphere, impacting the natural greenhouse gas balance and contributing to global climate change.