Researchers used moss samples from two peat bogs in Finland to measure the amount of CO2 released by decaying peat. By analyzing bomb-produced 14C levels, they found a peak in 1965, indicating the age of the peat layer. This allowed them to estimate the CO2 emissions from the bogs and how much was absorbed by living plants. They also observed variations in carbon isotope values, suggesting changes in CO2 emissions due to factors like temperature and precipitation.