Don't look now, but no less than the United Nations projected the world population to reach 8 billion last Tuesday, 15 November, double the population of 48 years ago. It is a milestone occasion celebrated as World Population day.

Amid falling growth rates, however, the latest projections suggest that the world's population could grow to around 8.5 billion in 2030 and 9.7 billion in 2050. It is projected to reach a peak of around 10.4 billion people during the 2080s and to remain at that level until 2100.

More than half of the projected increase in the global population up to 2050 will be concentrated in eight countries that include the Philippines. The rest are the Democratic Republic of the Congo, Egypt, Ethiopia, India, Nigeria, Pakistan, and the United Republic of Tanzania.

By next year, India is expected to surpass China as the world's most populous country.

Although World Population Day should be an appropriate time to celebrate humanity's diversity and marvel at advancements in health that have extended lifespans and dramatically reduced maternal and child mortality rates, UN Secretary-General Antonio Guterres said it is also a reminder of our shared responsibility to care for our planet and a moment to reflect on where we still fall short of our commitments to one another.

With such ballooning figures, questions are inevitably raised. Will we have enough food for a growing population? How will we take care of more people in the next pandemic? How do we manage climate change?

Environmentalists contend that all these risks have three things in common — health, climate change, and a growing population. Of the three, climate change is what medical experts and groups consider the one at the top of the totem pole due to its consequences on human health.

No less than President Ferdinand Marcos Jr. called on world leaders to act decisively and immediately on pressing global issues, primarily climate change and food security.

In the recent ASEAN summit, Marcos cited the Philippines' experience in dealing with severe tropical storm "Paeng" as among the direct effects of climate change.

"It was a very strange one because it was the very first one in our history where every single part of the country was affected by one typhoon," he told Trudeau.

"From up in the northern part, the northern island of Luzon, all the way down to the southern part of the Philippines. Everybody felt it and felt it badly."

Marcos explained that the consequences of climate change severely impacted the Philippines, which is very vulnerable due to its geography. He described the Philippines as a sink that absorbs carbon dioxide.

During his intervention in the 17th East Asia Summit, the President likewise underscored the importance of attaining self-sufficiency, as well as the adaptability of the Association of Southeast Asian nations despite numerous threats to the global food chain.

"It has become glaringly clear that there is a dire need to strengthen food security towards self-sufficiency in our region, to increase adaptability and resilience in the face of threats to the global supply chain," he said.

Indeed, it is incumbent upon us, for our sake and that of future generations, to act decisively and immediately on climate change.

Addressing the health burden on low and middle-income countries is pivotal. Often, the most vulnerable people in these countries face the greatest harm from climate change without having the resources to protect their health and environment. Population growth can deepen these iniquities.

The impact that food security and climate change have on human health has emerged as a dominant topic in public health research. Therefore, understanding and assessing the role these environmental exposures play in observed health concerns is critical for informing and developing clean air and climate policies, health promotion strategies, and interventions.