The content of this website is no longer being updated. For information on current assessment activities, please visit http://www.globalchange.gov/what-we-do/assessment
Major Warming and Cooling Influences on Climate
The figure above shows the amount of warming influence (red bars) or cooling influence (blue bars) that different factors have had on Earth’s climate over the industrial age (from about 1750 to the present). Results are in watts per square meter. The longer the bar, the greater the influence on climate. The top part of the box includes all the major human-induced factors, while the second part of the box includes the Sun, the only major natural factor with a long-term effect on climate. The cooling effect of individual volcanoes is also natural, but is relatively short-lived (2 to 3 years), thus their influence is not included in this figure. The bottom part of the box shows that the total net effect (warming influences minus cooling influences) of human activities is a strong warming influence. The thin lines on each bar provide an estimate of the range of uncertainty. Image Reference: Forster et al.1
References
- 1. [3] Forster, P., V. Ramaswamy, P. Artaxo, T. Berntsen, R. A. Betts, D. W. Fahey, J. Haywood, J. Lean, D. C. Lowe, G. Myhre et al. "Changes in Atmospheric Constituents and in Radiative Forcing." In Climate Change 2007: The Physical Basis, edited by S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor and H. L. Miller, 129-234. Vol. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK and New York, NY: Cambridge University Press, 2007.
Summary
| High-resolution | High-resolution JPEG |
|---|
