The onset of the New Year has been greeted by concerning stories about a new global epidemic. The World Health Organization has warned that a new epidemic in South America is “explosively” spreading and declared it a Public Health Emergency situation.

As of early February, the Zika virus has spread to as many as 33 countries in the Western Hemisphere and is now sprouting elsewhere. Countries in South America have now seen thousands of new cases of microcephaly, a brain defect syndrome presumably caused by the virus.

Brazil, one of the countries hardest hit by the epidemic, is now mobilizing all its national resources to combat this mosquito-borne disease. For Brazil, this epidemic could not come at a worse time, as the upcoming summer Olympics in Rio de Janeiro is just 172 days away.

A strong travel advisory already issued by many countries will certainly affect the summer games in terms of the number of tourists and, potentially, participating players. According to medical researchers, it was a previous global sporting event — World Cup 2014 in Brazil — that brought this Uganda-originating disease to the country.

The sudden spread of the Zika virus is a hallmark of the two new defining factors of the global community of today: globalization and global warming. It was as long ago as in 1947 that this virus was first identified in a Ugandan forest. Since then, only sporadic outbreaks have been reported, making it an endemic disease confined to certain places.

In just a few years, however, the disease has traveled and spread with alarming speed. The pathogen can travel with tourists and mix with other people just as easily as we people can. So, once regional endemics are now waiting for detonators of fast travel and global events so as to be propelled to far corners of another continent in a matter of days or weeks.

And yet, the fast travel and a variety of global events will continue their course in a straight line in the future. A new pandemic is ready to emerge at any time.

On the other hand, the new infectious disease is the latest evidence of the formidable danger of the global warming. The warmer weather has enabled mosquitoes to breed better and survive longer. Heavy rainfalls and the resultant stagnant water have also contributed significantly. The rising temperature and intense downpours globally introduce an optimal environment for mosquito-borne diseases.

As we know, the term global warming usually invokes a vision of rising sea levels, drowning coastal towns and disappearing islands. But it seems that before water takes a heavy toll on us, warm weather caused-diseases, old and new, will claim more casualties.

As a matter of fact, Brazil has been fighting against mosquito-borne diseases for a long time. In a 2005 trade dispute with European Union involving an import ban of retreaded tires from Europe, the Brazilian government underscored the importance of controlling the mosquitoes as a critical public health issue in the country and attempted to justify the import ban from that perspective.

While the position of Brasilia did not ultimately prevail, its explanation did expose the extent of the national health problem posed by mosquitoes. Recent development of Zika virus apparently shows the urgency of the problem in the country.

The existing problem has been further exacerbated by global warming. In fact, the record indicates that 2015 was the warmest year in South America since record-taking began.

As global warming is an issue where we cannot change the tide overnight, we will probably continue to see breaking stories of new epidemics in future newspapers. The sooner we change the tide, the more likely we keep these diseases under control.

Therefore, global warming is not just a “green” issue, but also a critical health issue. The Zika spread is yet another example pointing to the need to combat global warming, and combat it as soon as possible.

By Lee Jae-min

Lee Jae-min is an associate professor of law at Seoul National University. — Ed.