Biodiversity Leakage: Rewilding’s Biggest Problem

December 2nd, 2025
Brogan Jones

Since the rewilding topic was first announced, I had a feeling that it was going to be an uphill battle for the affirmative to win in most traditional rounds. This was mainly because I worried that the aff would have to prove that rewilding is the only feasible solution to climate change, or that it’s a necessary component of any sustainable solution. If the aff is unable to prove that, then the neg has a pretty easy path to the ballot:

Prove that there are some drawbacks to rewilding in the United States (such as agricultural production, economic harms, etc.)
Bring up that there are countless other alternative ways to address the climate crisis

Combine those two factors, and you’re pretty much left with minimal reasons to vote affirmative. However, upon actually researching rewilding, I realized that it was indeed going to be an uphill battle for the affirmative in most traditional rounds, but not necessarily for the reasons that I had initially thought. Instead, I realized that the real challenge for the aff wasn’t going to be defending rewilding as a policy, but rather defending where that policy is carried out.

Because the entire path to the ballot for the affirmative in most rounds depends upon winning the climate change debate, any negative argument that manages to turn climate change is going to be a big roadblock for the aff. Unsurprisingly, one of the most common negative arguments that I’ve encountered does just that. The argument, in its simplest form, is that rewilding land in the US (and really any part of the Global North) is uniquely bad because it sacrifices the least biodiverse land, which is most important for agriculture, and instead shifts that agricultural production to the more biodiverse Global South, resulting in a net biodiversity loss. This is known as biodiversity leakage. There’s a lot of great evidence and examples to back this up as well:

A report from Yale Environment found that, “as wealthy countries rewild farmland, they are driving the destruction of forests in poorer countries that are more abundant in wildlife. When industrialized nations in Europe and North America reclaim farmland, “the resulting shortfalls in food and wood production will have to be made up somewhere.” The report goes on to detail how nations in Africa and South America tend to pick up the slack, potentially incurring 5x more damage to biodiversity than benefits.
Another article further explains the concept, detailing how rewilding nature-depleted nations can push food and fuel production overseas. One expert even stated that we would be, “increasing our footprint…offshoring the problem.”
A report from the University of Cambridge emphasizes just how harmful this phenomenon would be to conservation efforts, undoing countless amounts of progress that have been made towards protecting biodiversity in the Global South. The article notably states that, “if protesting a logging concession in the USA increases demand for pulp from the tropics, then we are unlikely to be helping biodiversity.”

From an affirmative standpoint, this is a tough argument to get around, as it’s a pretty logically appealing concept. It’s also a great strategic move from the negative, not only because it is a tough argument to counter, but also because a lot of affirmative evidence on this topic is bound to be about rewilding as a general concept, not necessarily about rewilding in the United States. And, even if proposals are about rewilding in the U.S., they are unlikely to have examined any of these impacts or trade-offs. A lot of the affirmative evidence is simply lacking a response to this argument, meaning it’s a strategic exploitation of that weakness. This doesn’t mean that the argument is necessarily a checkmate. The affirmative could point to successful biodiversity gains from rewilding projects across Europe. Another response could be that not a significant amount of agricultural land would necessarily need to be sacrificed, or that if it were, that wouldn’t necessarily mean that production would shift to the Global South. Still, even though there are some responses to it, I would still call biodiversity leakage one of the strongest arguments on this topic. It allows the negative to get around a lot of the affirmative, to outright say that it’s not rewilding as a policy that the negative takes issue with, but rather where the affirmative is proposing that policy be carried out.