Currently, the United Nations (UN) estimates that there are approximately 7.7 billion people in the world, a number that is expected to reach 10 billion by 2050. Moreover, human populations are becoming more dense: 68 per cent of people are expected to live in urban centres by 2050. As these cities become more populated, their reliance on the local environment is expected to increase as well. In addition, climate change is projected to further reduce ecosystems’ ability to meet humanity’s growing demands.

This was the motivation behind a study published in Science this past October that examined the global mismatches between what nature can provide—termed nature’s contributions to people—today and in 2050.

Elena Bennett, a professor in the Department of Natural Resources at McGill and a co-author on the article, further explained the motivation for the study and the way that researchers modelled nature’s contributions to people across the world.

“In this paper, what we really wanted to highlight was when you get a service, […] what slice of that is nature providing, and how important is that?” Bennett said in an interview with The McGill Tribune. “The way the model is built has two components. [First], where is nature that can provide a service? For example, for pollination, where are there pollinators [and habitats] that can support pollinators? [The second part] looks at where that is needed.”

Using three different projections, the two-part modelling approach revealed areas where nature is not meeting the needs of people and is unlikely to meet them in the future. This is especially true in regions in Africa and South Asia. 

The different projections did lead to some unexpected results. A projection labelled ‘fossil-fueled,’ a situation in which human use of fossil fuels has greatly expanded, leads to better overall outcomes for the global human population. In contrast, the ‘regional rivalry’ projection, detailing a world where resources are very scarce, would lead to an overall worse global outcome. Although surprising given the notoriety of the fossil fuel industry, Bennett explained that the outcome would arise due to a closing-off of borders and a reduction in global cooperation in the regional rivalry projection.

“Where Africa and South Asia have issues, it gets worse [under the regional rivalry projection] because there is no ability to use trade to mitigate or ameliorate the situation,” Bennett said. “In the fossil-fueled development, it’s […] development […] with the intention of preserving green space. It’s business-as-usual but with a little intensification.”

This points to the importance of global trade networks in facing environmental change: For example, global food trade is already identified as an important contribution to food security facing a changing climate. Still, trade does not work equally well for all of nature’s contributions to people.

“With other things like flood control, it doesn’t work unless you can move all the people from Bangladesh, [for example],” Bennett said. “But you can’t put more mangroves in Malaysia and hope that it’s going to help.” 

Bennett mentioned that technology can be an important proxy for nature where trade is not able to keep up with human populations.

“In [North America], we don’t rely on wetlands to provide water quality,” Bennett said. “We build water treatment plants. That’s a technological solution to something that, in the right place with a less dense population, nature would have done for us.”

In the study, the best-performing future scenario was labelled ‘sustainability.’ Bennet further elucidated what sustainability might need to look like to improve our global forecast.

“That’s the million dollar question: We don’t know,” Bennett said. “What this paper shows is [that] some combination of [conservation, technology, and trade] is what we really need, but we also really don’t know the implications of these.”