Dessler has been consulted by newspapers and has given talks on climate change and government policy. On January 16, 2014 he testified before the US Senate Committee on Environment and Public Works. He stated that with almost 200 years of study by the scientific community of the climate system a robust understanding has emerged. He continued stating, the climate is warming and "humans are now in the drivers seat". He concluded, "We know that, over the next century, if nothing is done to rein in emissions, temperatures will likely increase enough to profoundly change the planet." He gave a talk at the Goddard Space Flight Center in 2013 titled, "The Alternate Reality of Climate Skeptics" in which he explained how "climate skeptics have constructed an alternate reality to believe it [sic]. In this way, the debate over climate change turns into a debate over which reality should be believed." In 2010 when US Senator James Inhofe attempted to block the US Environmental Protection Agency from regulating greenhouse gases under the Clean Air Act, Dessler told reporters he was confident that individual errors dont invalidate the scientific consensus that global temperature is rising stating, "That's not how science works." He asserted his confidence that the climate is warming due to human activity and that this will have "catastrophic impacts" stating, "The evidence includes a mountain of data." Dessler cited replication by multiple institutions as support.
Dessler has suggested that scientists advocating for climate change mitigation should tell their personal stories and that this would reveal the strategy of ad hominem attacks by climate change deniers, an attempt to portray scientists to audiences as "not like them." He said by revealing their backstory scientists can build trust and show people that they share their values. In December 2013 Dessler spoke at a workshop about his experiences with a request for all of his emails at Texas A&M from the American Tradition Institute's Chris Horner using the Texas Public Information Act. He had received support from Scott Mandia of the Climate Science Legal Defense Fund, the Public Employees for Environmental Responsibility and the Union of Concerned Scientists.