I have a son who is 2 years old, and he might never see a wild hedgehog.

It is a realisation that came to me only recently. I grew up watching hedgehogs regularly in the garden. They populate the pages of the story books that I once read and which I now read to him – he knows exactly what they are, and he loves them. There are still quite a few hedgehogs left, but the truth is that their numbers have absolutely plummeted in the wild in the UK. So, unless something changes, both soon and radically, there is a very good chance he will never casually encounter one on British soil.

This, as we know, is a pattern being repeated for people everywhere across the gardens, farmlands, wildlands and oceans of the planet. Some people might be willing to accept the idea that the next generation will no longer see the wildlife that we grew up accustomed to, although I am not one of them. However, most people will surely be less willing to accept the problems caused by massive ecosystem degradation, of which hedgehogs and other missing wildlife species are symptomatic. And what all this highlights is that it is not enough – not nearly enough – for conservation to focus on protecting what nature remains. We must find ways to not only halt, but also to reverse, biodiversity loss.

And yet.

I have another son who is 1 year old.

Even in the UK, infant mortality rates for children under the age of 1 have dropped by 62% since the year I was born. A wealth of research suggests that there is a strong correlation between a country’s state of economic development and the survival rate of its youngest inhabitants. In fact, the precipitous global drop in infant mortality rates is one of numerous incredible achievements of economic development over recent decades. Such achievements make a strong moral argument for seeking further economic development, particularly in poorer and/or less industrialised parts of the world.

And economic development activities often come at a cost in that they have certain impacts upon nature – indeed, it is likely that habitat clearance and overharvesting of natural resources remain the two largest threats to global biodiversity. Consequently, we cannot simply protect all of the nature that remains; at least, not if we see value in some form of economic development.

Instead, we must turn to considering the ‘net outcomes’ of human activities for nature. This is not a perspective currently incorporated into leading global conservation agreements, but perhaps it should be. Taking a ‘net outcomes’ approach requires (1) quantifying the likely biodiversity impacts of development, (2) preventing those wherever that is possible or where the impacts are too great to accept, (3) physically compensating for those impacts in a way that balances out any losses, and (4) then going above and beyond by putting in place additional conservation actions. The focus then would not be primarily on retaining the final fragments of impoverished ecosystems, instead, it would be on making sure that net outcomes are positive (minimising impacts, and seeking conservation gains wherever those might be found).

Now is an incredibly opportune time for a shift in the language of and approach towards global conservation policy, given ongoing discussions in advance of the 2020 meetings of the Convention on Biological Diversity (CBD), to be held in China, which will formalise the CBD’s strategic plan for biodiversity for at least the next decade. Adopting a net positive approach now would have major implications for the way that conservation is delivered and encourage greater engagement with nature conservation around the world.

Is it naïve to believe such an approach could work? Perhaps – although environmental policies with a ‘net outcome’ approach have become decidedly mainstream, including for biodiversity, and there is at least some evidence that these fledgling policies can be effective. Indeed, the UK has just launched a commitment to ‘net environmental gain’ across many types of development activities, and the country is far from a leader in this policy space. What is more, out of a very large body of scientific literature on the topic of net biodiversity outcomes has emerged a framework (the Conservation Hierarchy, which is an important element of our new paper on net outcomes today in Nature Ecology & Evolution) that could provide the basis via which net positive outcomes for nature are achieved. As with all approaches to conservation, there are practical challenges to implementation – some of which we flag and explore in the paper – but these are not necessarily insurmountable.

It is undoubtedly true, for better or worse, that biodiversity conservation must involve trade-offs to some degree with economic development activities. The real question is whether the conservation community, and the world, are willing to take the leap from a focus on actions that prevent biodiversity loss and towards a focus on the actual net outcomes of all our activities. The framework exists, with a growing body of science to support it – but does the political will?

If the right calls are made by those who make decisions in 2020, undoubtedly a ‘super year’ for environmental policy, then maybe we can move on from the narrative that economic development is inevitably synonymous with biodiversity loss. Maybe we can continue on a path of more restrained, and fundamentally equitable economic growth that simultaneously allows us to seek the protection and eventual return of the wildlife that we are losing.

And one day, maybe, both of my sons will see a wild hedgehog.