Global Warming FAQ

The document identifies human activity—specifically the burning of fossil fuels and tropical deforestation—as the primary cause of global warming. It explains that carbon dioxide (CO2) is the most significant driver of climate change due to its high radiative forcing and abundance, outweighing other heat-trapping gases and natural climate drivers like solar intensity. The text clarifies that the ozone hole is not a cause of global warming, though both result from human atmospheric alterations. Observed impacts include a 1°C increase in global average surface temperature since the pre-industrial age, rising sea levels, and ecological shifts such as thawing permafrost and altered species ranges.

• Human activities, primarily the burning of fossil fuels for electricity, transport, and business operations, as well as tropical deforestation, are the main drivers of global warming.
• Scientists distinguish human-induced CO2 from natural sources by analyzing the ratio of heavier to lighter carbon atoms, which shows that fossil fuel emissions have been the largest contributor to atmospheric CO2 since the pre-industrial era.
• Carbon dioxide is the most critical heat-trapping gas because it has the highest positive radiative forcing of all human-influenced climate drivers compared by the IPCC between 1750 and 2011.
• Natural factors, such as changes in solar intensity, cannot account for the magnitude and distribution of the rise in global mean temperature over the last century.
• Observed indicators of global warming include a global average surface temperature increase of approximately 1°C since the pre-industrial age, alongside rising sea levels and the thawing of permafrost.

APA

Union of Concerned Scientists (2008). Global Warming FAQ. https://www.ucs.org/resources/global-warming-faq

Chicago

Union of Concerned Scientists. Global Warming FAQ. 2008. https://www.ucs.org/resources/global-warming-faq.

Wikipedia

{{cite report |author=Union of Concerned Scientists |title=Global Warming FAQ |date=16 July 2008 |url=https://www.ucs.org/resources/global-warming-faq |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{unionofconcernedscientists2008global, author = {{Union of Concerned Scientists}}, title = {{Global Warming FAQ}}, institution = {Union of Concerned Scientists}, year = {2008}, month = jul, url = {https://www.ucs.org/resources/global-warming-faq}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }