When it comes to climate change, science-based facts prove the looming problem is real. But to gain broader understanding among skeptics and the general public, advocates should refocus their conversations on the positive outcomes of climate action, says Rob Jackson.

“What people care most about are health and safety,” said Jackson, the Michelle and Kevin Douglas Provostial Professor at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth). “These factors motivate people more than the greenhouse gas question.”

Jackson delivered a comprehensive talk Jan. 25 titled How Cutting Greenhouse Gas Emissions Improves Our Water, Air, and Health, as part of the Earth Matters lecture series co-sponsored by Stanford Continuing Studies and Stanford Earth. About 60 people attended the lecture, including community members, students, and Stanford faculty.

Beginning with the history of climate science, Jackson discussed a wide variety of research in the field, including global warming predictions, the impacts of fracking, and how policy changes have curtailed methane leakage.

“Well over 100 years ago, people had already made the link from burning fossil fuels to changes in the Earth’s atmosphere,” Jackson said. “They understood the basic physics, and the basic physics has not changed since then.”

There is “no uncertainty that the Earth is warming” and it has been 40 years since we have experienced a cooler-than-average year, said Jackson, who chairs the Global Carbon Project, an initiative that places fossil fuel emissions in the context of natural carbon dioxide sources like deforestation and ocean uptake and release. To explain the concept of cumulative emissions, Jackson described the atmosphere as a bucket that can hold only a certain amount of CO2 before a given temperature increase occurs.

Analyses of cumulative emissions show people generated about 500 billion tons of CO2 through 1960, and that number has increased to about 2,000 billion tons today. Presenting a graph of current global fossil fuel emissions, Jackson reflected on some positive aspects of current trends: Fossil fuel emissions have been stable for the past three years. Previously, lower CO2 emissions only occurred when the economy shrank, he said.