Scientists’ claim that human activity is destroying nature to the point it could potentially doom humanity itself may seem too immense for the average person to fully understand, but a Canadian professor heavily involved in the writing of the new United Nations report sees it differently.

Kai Chan sees signs of the problem in the recent floods in Ottawa and elsewhere. He says climate change likely contributed to the flooding by leaving the capital with an exceptionally high snowpack and giving it conditions that warmed extremely rapidly.

When the water started to flow, the ground wasn’t able to absorb it as easily as in the past, because wetlands and other areas had been paved over in the name of development.

“Those kinds of events are usually a breakdown in nature’s ability to provide those self-supporting services,” he told on Monday from Paris, where a United Nations report providing the most comprehensive look ever at the decline of nature was unveiled.

“We’re talking about maintaining the conditions … that enable us to grow food. We’re talking about the watersheds that provide us with clean water. We’re talking about the wetlands and the rivers, and the … floodplains that mop up floodwaters and prevent flooding, which we saw in Ottawa.”

Chan, a professor at the institute for Resources, Environment and Sustainability at the University of British Columbia, was a co-ordinating lead author of the report.

The report found that one million plant and animal species could face extinction within decades, while humans are facing significant risks when it comes to food and water security, as well as overall health.

It lays blame for these problems at the feet of land development, overfishing, human-caused climate change, pollution and other human activities. It forecasts what Chan described as a “more chaotic” future for humanity if the decline of nature is not addressed in a significant way – even without taking into account human reactions to the worsening situation.

“What is not so clear is how people would respond,” Chan said.

“We can’t tell you whether there’s going to be social collapse in 2050 [because] that is dependent on too many things that are yet to be decided.”

The thinking goes something like this: droughts and other extreme weather events will be more frequent. Among other effects, this will have a significant impact on food production, leading to price increases and shortages. As those resources become scarcer, history suggests that humans will be more likely to turn to conflict.

Though not specifically covered in the assessment, it’s that threat of conflict and overall social unrest that has Chan concerned about the world his daughters will grow up to see.

“I want them to live in a world where we have banded together, we have looked at the scale of the problem and we have thrown the full weight of our human resources into solving that problem in a fair and equitable matter,” he said.

“I don’t want to live in a world where we continue to stick our heads in the sand and deny that it’s happening and fight between ourselves about the limited resources and the difficult conditions that so often result.”

Chan has a number of ideas for how Canada can confront the looming crisis, including building ecological literacy into school curricula and pushing environmental science to the forefront of news coverage about devastation caused by extreme weather events.

“All of those stories deserve to represent at least a little bit of what we know about how those things come about,” he said.

On the government side, he sees promise in carbon pricing and the new regulations for environmental assessments proposed in Bill C-69, though he’d prefer if they went further.

Ultimately, though, he believes the biggest change needed is for the world to find a way out of the existing dichotomy where environmental protections are seen as harmful to economic activity – likely by finding better ways to link the two together.

“Pretty much anywhere on the planet, we’re faced with this choice between damaging development and the jobs that go with it … or allowing it to be exported elsewhere where they’ll do the same kind of extractive activities but probably [with] less environmental protection,” he said.

“If it weren’t like that, if we had a situation where across the board, globally, we accepted that development had to mitigate the major environmental impacts that it causes … it wouldn’t be a trade-off between jobs and the environment, because everywhere we would be protecting the environment.”