The world needs people like Andy Jorgensen, a professor of chemistry and environmental science at the University of Toledo. One of Jorgensen’s jobs is to create educational material on global warming, its impact, and what we can do to fight against it.

In a conversation with Redditors, Jorgensen talked Feb. 14 about the difficulty of communicating climate change and the tricks he employs to convert climate-change deniers. We’ve curated and condensed the best bits for ease of reading.

How do you communicate the scale of the emergency while mitigating panic and hopelessness?

I use the analogy of a fever. The Earth’s temperature has changed about 1.8 °F [1 °C] in recent decades. This is comparable to a child with a fever. It is not life-threatening. But it should not to be ignored. By 2050 middle estimates of temperature increase are almost 4 °F, which would be very serious for a child and about the point at which climate scientists say irreversible changes would occur on Earth. By 2100, the rise could be 6 °F—and remember that this is an average, with the Arctic seeing about twice this. So like the child’s fever, we must act quickly and decisively.

Some studies say a big reason for climate-change denial is that climate change makes people feel scared and powerless. It’s more comfortable to believe that something that threatens our entire planet is a myth or a lie. How do you counter that?

I believe there are several reasons why we don’t want to believe—and, more importantly, act. First, we do not like to be told that we need to change, particularly for something as broad as climate change. We don’t even like to exercise when we are told we should. Second, the changes are hard to detect, though that is getting easier. Third, there are those who believe, sometimes for religious or other social reasons, that humans can not possibly change the earth. Looking at photos from Asian cities will tell you that we can.

In my talks, I also include a discussion of what we can do to reduce the problem and note the values—saving money, creating green jobs, using free energy from the sun and wind. I have found from the data I collect at my talks that 20% or so of individuals will change their mind if shown compelling data.

What is the strangest reaction or comment you’ve gotten from a climate-change denier?

I was once heckled by someone who yelled out at a honors banquet that water is a greenhouse gas so are we going to get rid of it. Of course water is a greenhouse gas. Fortunately water, carbon dioxide, and other gases makes the Earth warm enough to live. On average we would be freezing if it were not for these gases. So we like the greenhouse effect, but we don’t like the present enhanced greenhouse effect. Regarding water, the concentration of water in the air is increasing and it affects rainfall, including more instances of intense rainfall. But the increase has not been comparable to the 40% increase in carbon dioxide since the Industrial Revolution.

How do you respond to people that believe, as Matt Ridley presented to the Royal Society last year, that science has not provided sufficient evidence to suggest that global climate change is inherently dangerous?

Deniers make an impact well beyond what their science indicates. Yes, there is little patience with those deniers who keep making false statements—like the so-called pause in temperature increases. The last three years of record increases should close down that argument.

To quote the idea of Richard Alley and others: if a scientist found a truly compelling argument that the present understanding was so far wrong such that the 40% increase in carbon dioxide in the air in a few lifetimes was not the problem, that person would make their reputation. Everyone in climate science would like to be shown that the problem is not as bad as the present evidence indicates, but it has not happened as yet. It would have to be something fundamental in the science, which as been around for over 100 years and in which no one has found a flaw.

What would be your suggestion to increase scientific literacy in the face of strong political resistance?

Early education is valuable for any type of learning, including science. I teach a course that includes elementary education majors and last week I gave my presentation to a group of elementary school teachers. So educating the educators has been an emphasis of mine. Science is not magic or not unintelligible, but it is challenging to teach accurately and in a comprehensible way.

Science matters: It impacts health through nutrition or medicines; through the economy through more efficient autos and appliances that save you money; and in creating career opportunities—they are more jobs in renewal energy than fossil fuel production.

Are voter priorities wrong?

Anthony Leiserowitz and Edward Maibach at Yale University show that 70% of those in the US believe that climate change is happening—and this was polled after the 2016 election. Even about half of the supporters of US president Trump believe that climate change is really happening.

But climate change polls low on people’s priority list because other issues are closer to home: jobs, crime, and for some terrorism. But it is quite clear that climate change will affect your life more than terrorism for the vast majority of people—just more slowly.

So, yes, voters’ priorities are wrong, hence my reason for speaking to so many audiences and on so many forums like this one. It may well take significant negative consequences to move that needle. Recently I have taken to adding a slide to may talk that urges listeners to speak to others. This is real and there is a price to be paid, especially for the younger generation. I got into this area just a few years ago when my first grandchild was born. In 2100, when the world will see major negative impacts which may be almost impossible to avoid, she will be younger than my mother is now. She and her generation will be paying a price, but perhaps we can put a down payment down right now, just like for her college expenses.