As a new coronavirus spreads within China and to other countries, I’m reminded of my time in Hong Kong during the SARS outbreak of 2003.

Back then, I spent an otherwise beautiful spring wearing masks in public but mostly working from home, as I reported on the disease and the struggle to contain it.

Every day at the same time I checked an official Hong Kong website, which I trusted completely, to see that day’s new cases. I remember my relief as the number finally trended down. When it was over, it felt as though SARS had been just a shot across the world’s bow.

For one thing is certain: The next pandemic will come, and it may resemble the Spanish flu of 1918, which infected half a billion people. The questions are when, where and how, and whether we’ll be ready collectively. I say “collectively” because a pandemic, like climate change, doesn’t respect passports or borders. We don’t quarantine, cure or save “America First,” or “China First” or anybody first; we either put humanity first or we all lose.

There are other links between climate change and pandemics (and, to be clear, the current outbreak is still far from being one). The main connection is that global warming actually creates new disease vectors. As the permafrost thaws in places like Siberia, viruses that have been frozen for millenniums, and against which animals and humans no longer have any resistance, will resurface.

And as desertification and other side effects of warming move the boundaries between habitats, species will come into contact with creatures they’ve never encountered before. That’s how viruses start their journey.

What, then, are my lessons from the SARS outbreak? First, we must plan for human nature, both in its perfidy and its heroism. I observed SARS crash into various cultures in totally different ways.

China at first suppressed information about it, fearing economic loss or political turmoil. But that allowed the virus to spread farther and faster for longer than was necessary. And once China did open up on the subject, its people no longer trusted the government’s information. Rumors circulated and often prevailed over facts, hampering the official response.

Singapore, by contrast, lived up to its reputation for iron discipline with immediate quarantines that I initially considered draconian and illiberal but came reluctantly to respect. Taiwan initially showed the darker side of individualism, as some hospital workers, to protect themselves and their families, shirked their duties. In Hong Kong (and then Taiwan and other places, too) the opposite happened, as nurses and doctors cared for the victims and valiantly fought the virus.

Nobody who’s read Albert Camus’ “The Plague” or Jose Saramago’s “Blindness” should be surprised that human beings, individually and in crowds, will respond unpredictably to such crises. Some will hoard scarce medicine or food that’s more urgently needed by others. Some will break quarantines to be with loved ones. Some will do their duty, others won’t.

The biggest lesson, which China seems to have learned, is that the government must be ruthlessly honest and transparent. The more facts, the better. Hide nothing. It was my trust in that Hong Kong website that eventually made me believe SARS was waning. Once trust between the population and the state breaks down, controlling an outbreak becomes almost impossible.

Another lesson is, thankfully, one we’ve already learned. Screening and surveillance, which should be used with caution in free societies, becomes necessary in an outbreak and is effective. Even now various airports around the world are digitally observing the body temperatures of passengers arriving from Wuhan, the center of the new outbreak.

Quarantine should be voluntary at first and actively encouraged by employers and government. Whoever can work from home, via Skype and such, should do so, without fearing recrimination. The more people can keep acting on their own volition, the more “agency” they believe they have, the calmer and more cooperative they will remain. Once an outbreak goes out of control, of course, quarantines must become mandatory.

But the most profound lesson is that we must cooperate as a species, with a geopolitical approach that seems to have gone out of fashion: multilateralism. We’ve always been locked in an arms race between the evolution of viruses, bacteria and fungi and our medicines against them. When a new virus appears, it potentially threatens all of us and should be fought by all of us together.

That means a new bug’s genome, wherever it’s first collected, should be sequenced and immediately made available, like open-source computer code, to certified researchers everywhere. (You still need the World Health Organization or some such body to accredit the scientists, lest the genome gets into the hands of terrorists). All labs and scientists should then share their insights with the entire profession.

The bad news is that we cannot be sure that humans will rise to global threats such as climate change or pandemics, because we’re so prone to put what we perceive to be our own interests, or our nations’, first, only to suffer the consequences later.

The good news — and this too is something I learned from SARS — is that every time we do join together to defeat a new threat, we’re reminded how much we have in common, and fight better the next time.

Andreas Kluth is a member of Bloomberg’s editorial board.