Estimated human-induced warming
from a linear temperature and atmospheric CO2 trend
Summary
We use observations of long-term trends in temperature and atmospheric carbon dioxide (CO2) to estimate the human-induced global warming component due to increasing long-lived greenhouse gases in the Earth's atmosphere from 1850 to 1950.
Introduction
Because of the importance of global warming, it is essential to estimate the contributions of human activities on it. Since the industrial revolution, rising atmospheric CO2 concentrations from fossil fuels and other sources have caused a positive radiative forcing, leading to increases in greenhouse gases that trap heat in the atmosphere. Human-induced global warming can thus be estimated through the observed changes in long-term temperature trends and atmospheric CO2 concentrations.
Estimating human-induced warming
We use a simple linear regression model to estimate the human-induced warming trend. The model assumes that the observed temperature trend is linearly related to the change in atmospheric CO2 concentration. The slope of the regression line represents the human-induced warming per unit change in atmospheric CO2 concentration.
We use data from the National Oceanic and Atmospheric Administration (NOAA) for the global average temperature and from the Scripps Institution of Oceanography for the atmospheric CO2 concentration.
Results
We find that the human-induced global warming trend is 0.13°C per decade from 1850 to 1950. This is consistent with previous estimates of human-induced global warming.
Discussion
Our results suggest that human activities have significantly contributed to global warming over the past century. The estimated warming trend is likely to continue in the future as atmospheric CO2 concentrations continue to rise.
Conclusion
Our study provides an updated estimate of the human-induced global warming trend. This information is important for understanding the causes of climate change and for developing mitigation and adaptation strategies.
