According to Cicerone, although geoengineering research is "necessary and justified", implementation should not be considered now. He drew what he called a good analogy to the 1975 Asilomar Conference, where scientists voluntarily agreed to ban certain experiments in recombinant DNA, which was at that time a new area of research. Cicerone suggested that the approach for geoengineering be "research is necessary, but we know we are not ready to try any large-scale intervention – we want to get everybody together to agree on what would be the monitoring and quality assurance, legal implications, and so forth.”

A leading climate scientist, Cicerone reviewed decades of research, some of it conducted by himself and colleagues at the US National Center for Atmospheric Research (NCAR) and the University of California, Irvine. Although his audience of science writers scarcely needed convincing, he described multiple lines of research going back several decades that lead to the conclusion that the Earth is warming and that human activities are the main cause.

Cicerone also addressed the New Horizons in Science meeting in 1988, a time when evidence of anthropogenic global warming was already accumulating. "In the early 1980s," he said, "the prospect that humans were capable of changing the planet's climate by adding greenhouse gases to the atmosphere was widely appreciated."

He recalled musing with climate scientists Veerabhadran "Ram" Ramanathan and the late Stephen Schneider at NCAR in 1985. The researchers asked: "Are we going to live long enough to see a signal of human-caused climate change? What will it be like? How many years will it take?" None of the three expected, he said, that we would see a signal as clearly and as strongly as we are seeing it now. At the time they concluded that by 2010, scientists might just begin to see clear evidence that would convince most people that climate change was happening, whereas in fact this evidence came much sooner.

Having suggested that greenhouse gas emissions must be reduced by 70% from current levels, Cicerone responded to a reporter who asked how that could be accomplished. "There's no magic bullet," he said. The answer will be "a little bit of this, probably, and a little bit of that". In the short run, energy efficiency is the most attractive approach. "We could probably cut back on energy usage by 20–30%, just by adopting efficiency methods," he said. "That's not conservation, that's not changing people's behaviour, that's changing technology."

Conservation, renewable energy and nuclear power would each save a few more percent of emissions, he added. To those who said this grab bag of solutions might seem inadequate to the task, Cicerone replied that it was actually a more stable approach than relying mainly on any one thing. "But it isn't going to be easy," he concluded.