The global population is now at 8 bn, a milestone that brings daunting — but not insurmountable — climate challenges: Earlier this week, the global population reached 8 bn people and is on course to reach 10.4 bn by the 2080s, the UN said. These figures, along with the fact that in many parts of the world we’re witnessing aging populations and severe climate change-linked catastrophes, are raising concerns about resource allocation and the economic viability of a growing human population.

More people could mean an even tighter strain on our dwindling natural resources: Meeting food, water, fuel and housing needs — all of which are increasingly coming under pressure due to climate change — for this growing population will become a major challenge in the years to come, the UN warns. This is also a problem when considering the fact that growing incomes will likely continue to hike demand for mass-produced consumer goods.

Making matters even more difficult is that much of the growth is concentrated in areas where climate risks are especially high: In places like sub-saharan Africa, which will experiencing the most growth over the coming decades “sustained rapid population growth can thwart the achievement of the Sustainable Development Goals (SDGs),” the UN warned. This includes access to electricity as population growth outpaces energy development, resulting in many countries in the region being held back from “green, resilient, and inclusive development,” the World Bank said recently. This gap in access to electricity will affect some 500 mn people in sub-saharan Africa alone by 2050 if we continue at the current trajectory.

Also troubling is the age demographics of the global population: The number of people 65 and over is expected to rise to some 1.4 bn by 2043 from 783 mn currently, according to UN projections. This means we’re looking at some 623 mn new retirement-age individuals in the coming two decades. Considering that it took some 70 years for this segment of the population to grow by 651 mn, the growth rate is a concerning statistic for many rich countries whose populations are rapidly aging.

The same is true for those over 80 as well: People over the age of 80 reached over 150 mn this year, about twice the number of those belonging to the same age group at the turn of the century.

For countries with aging populations, the economic implications are serious: For Europe, North America and Japan — where people over 65 already makeup at least 20% of the population — economic growth and living standards could take a downward turn, Shruti Singh, economist at the OECD Centre for Opportunity of Equality, told the Financial Times. But some public policy decisions like expanded access to childcare and healthcare could help curb some of these effects.

In Egypt, rapid population growth is more of a problem than aging right now: Egypt is one of eight countries where over half of the projected increase in the world’s population up to 2050 will take place, according to UN forecasts. Egypt’s population has now surpassed 104 mn, rising by more than 1 mn this year alone, and is expected to be near 160 mn by 2050.

But not all countries with a similar GDP are immune to aging: Though not yet at European and North American levels of aging, middle income countries in Latin America and Asia are proving to be the fastest aging worldwide, the UN report says. One third of the global increase in the number of people aged 65 and over will come from East and south-east Asia over the coming three decades.

Could technology force us to reconsider what counts as old? Optimists argue that aging populations in the future might not be as bad as we once thought. As medical advancements continue to take hold around the world, more people are able to live longer and healthier lives than they used to. Since the 1950s we’ve witnessed a drastic reduction in the mortality rate among 65-69 year olds. The real challenge then becomes expanding access to healthcare earlier in life so that those above 65 require less medical attention than they currently do.

There are also a handful of opportunities for low and middle income countries with growing populations: Though rapid increases in the number of youth in low and middle income countries can place a strain on already scarce resources and services like education and healthcare — scaling up financing for these systems could generate huge returns for these countries “generating virtuous cycles that can lift individuals, families and societies out of poverty and reduce inequality,” the UN said in its policy brief.

And ways to mitigate the environmental harm of growing populations: If the primary environmental challenge posed by a larger population comes from the increased demand for goods and fuel in their current form, more sustainable solutions — like expanded renewable energy production and more efficient agricultural practices (which includes a reduction in animal based products — could also help pave a way out of planetary catastrophe in the coming decades, according to the UN.