Nature needs half

Global warming and the end of incremental thinking

Simple climate action  //   I S S U E   # 4 8   //   R E W I L D I N G

On Monday, the Intergovernmental Panel on Climate Change laid out a stark choice: act now or watch temperatures soar well beyond the 1.5°C of warming. We’re now barreling toward a world 2.5°C to 4°C, hotter than one humanity has ever known. We may experience 1.5°C of warming (the target under the Paris Agreement) within a decade. If there was any solace to be found in the UN’s dispatch, it’s that apocalyptic scenarios — 5°C or more of warming — seems less likely on our current emissions trajectory. But so does a soft landing.

To avoid runaway warming haunting climate scientists’ nightmares, we need to curb human emissions. But it can’t be done alone. We’ll need Mother Nature’s help. Earth’s ecosystems soak up much of our carbon dioxide (and prevent even more from re-entering the atmosphere). Conservation, on a global scale, is essential to restoring a stable climate.

So we’re entering a new era of conservation. Expanding a park here, designating a reserve there is no longer enough. Conserving our climate means conserving vast swaths of our planet’s ecosystems. Two such efforts — “Nature needs half” and the 30x30 movement (a drive to conserving 30% of the US by 2030) — meet those demands.

This week, we’re featuring an interview between our writer Erik Ness and Will Steffen, professor emeritus at the Australian National University’s Fenner School of Environment and Society in Canberra. We’ll see what rewilding means for the climate, and what you can do.

As futurist Alex Steffen has written, it is no longer possible to think in terms of incremental change to achieve a net zero-carbon world. “Every approach that promises both bold action and the continuation of current practices and systems leads us inexorably into magical thinking,” writes Steffen. That might seem scary to some. But the alternative is far less appealing. Change will come whether we like it or not. Action, then, isn’t really a question. It’s just a matter of reacting to disaster, or acting to prevent it. Our poll next week will tell you what you can do.

Michael Coren

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Conservation’s rewilding moment

How much biosphere do we need?

By Erik Ness

Three summers ago, a terrifying thought experiment that became known as Hothouse Earth (no relation) went viral. A study, Trajectories of the Earth System in the Anthropocene, included one ​​particularly dystopian scenario where global warming spirals out of control. Natural carbon cycles are disrupted and become self-reinforcing. Earth slips into an epoch of runaway climate change we are powerless to influence. It’s hard not to revisit this in the wake of the IPCC’s renewed urgency.

“At what point are these tipping points going to basically take control of the system?” asks Will Steffen, lead author and Emeritus Professor with the Fenner School of Environment and Society, at the Australian National University in Canberra. “At what point do you start sliding towards that and can't stop the slide? We'll never know for sure.”

At least, we won’t know until it happens. Right now, scientists think we’re still unlikely to tip into a runaway climate catastrophe. We can still, mostly, define our climate future. Yet today, devastating wildfires in Siberia, Turkey and California echo the grim predictions of the Hothouse Earth report, and revisiting it can also help us understand the powerful potential of conservation to face down the climate emergency.

On January 27, just seven days after taking office, the Biden Administration issued an executive order designed to tackle climate change at home and abroad. Embedded in the announcements was a commitment to increase U.S. conservation lands to 30% by 2030. Often styled ‘30x30’ by advocates, this international movement aims to ambitiously scale up conservation to quell the dual climate and biodiversity crisis. It’s a legislative stepping stone en route to the more ambitious idea that “nature needs half”, the effort to set aside 50% of the planet for nature.

If you’ve spent any time in or around conservation over the last 50 years, the 30x30 and half-earth targets will require a seismic shift in your expectations. We’re accustomed to arguing for conservation in very modest-sized chunks of real estate. If you live in a populated region, one might celebrate 400-acre additions to regional parks, and every now and then you get to celebrate a victory the size of Tongass National Forest or Bears Ears National Monument — an area roughly the size of San Diego.

You win some, you lose most. For every small victory, conservationists suffer a daily death by one thousand cuts. Between 2001 to 2017 the United States lost natural area to development at a rate exceeding a football field every 30 seconds. Failing at conservation leads us ever closer to Hothouse Earth.

Converting nature to real estate is a double climate punch. Intact nature stores enormous quantities of carbon, and when we plow it under or build on top of it, that carbon is released. Intact nature also continually stores carbon. Development severs this link to the carbon cycle.

Conservation is perhaps our strongest road away from Hothouse Earth because, no matter how good our tech or our markets, we need nature to cycle carbon out of the atmosphere and back into ecosystems. That’s why it is so devastating that the Amazon rainforest is now emitting more carbon dioxide than it stores.

Conservation and climate activists often talk about living in a world of wounds. Embracing the idea that nature needs half is about flipping the script — plotting an affirmative path and going on the offensive.

Shot by Nikole Turrell for Hothouse

This week, we dig into the literature and put some fundamental questions to Will Steffen and a few other conservation experts about 30x30, map out the progress made so far, the shift in mindset that is needed to make a significant transition, and what each of us can do to take part in this critical movement.

The idea that nature needs half, and to conserve 30% of our land by 2030, sounds like marketing. Where’s the science?

30x30 is indeed a campaign, but the science behind it and the nature-needs-half movement is deep and broad. As early as the 1970s, conservation scientists in Florida were urging the state to set aside half of its land to preserve natural cycles. As the field of conservation biology matured, the scientific rationale escalated. Nature Needs Half arose from the work of people like Harvey Locke of the Yellowstone to Yukon Conservation Initiative, and pioneering ecologist Reed Noss. Their advocacy for large landscape preservation and restoring large predator populations led naturally to more sweeping plans. The Half Earth Project arose from E.O. Wilson’s long advocacy for biodiversity, crystalized in his book Half Earth. If you want to geek out at a high level on the science, read Wilson’s book, or visit Nature Needs Half to find links to numerous supporting papers.

Half is not an exact science. Steffen explains that, of nine planetary boundaries, the biosphere and physical climate are co-equals in their power to override the remainder. “How much biosphere do you need? We're a little bit more aggressive than the 50%” he says. Steffen’s group simplified the Earth system, looking mainly at major forested biomes because they play an inordinately important role in terms of the carbon cycle, the water cycle, and as habitat. Three stood out: The temperate forests of North America, the boreal forest of Canada and Siberia, and the Amazon. “We argue that you actually need three-quarters of those forests to be intact,” he says. Half is the minimum, and we should do better.” Local priorities may call for more.

That all sounds very ambitious. How far have we got?

According to the conservation  definitions used by 30x30 we have currently protected about 12% of the U.S. land mass, plus 26% of the ocean. By comparison, approximately 60% of U.S. land in the lower 48 states are in a natural condition. We’ve protected a lot, and, despite persistent losses, have the potential to protect a lot more.

Can we stop worrying so much about carbon if we focus on nature?

No. “We have to get out of fossil fuels,” says Steffen. Our energy systems are liberating fossilized carbon (in the form of coal, oil, and gas) sequestered by Earth’s plants millions of years ago. Degraded ecosystems cannot handle much more on a time scale meaningful to humans. 

Is this all going to become government land? Aren’t some people already upset about how much government land there is?

Some interest groups have already dug in behind traditional battle lines. The state of Kansas has already passed a law to “defend” against what it calls the 30x30 “land grab.” The Biden Administration has stated that it will rely on voluntary conservation to reach targets, and hopefully community alarm over drought and fire will coalesce into a more collaborative approach. Government-sponsored conservation work like the Conservation Reserve Program is popular and traditionally oversubscribed. With new funding from carbon markets and by tweaking the biodiversity objectives, these approaches could be even more effective while bolstering rural economies. There is also significant support for 30x30 within the hunting and angling community.

Even within the U.S. we’ll need a variety of approaches. If you look only at forested lands there’s a continental divide, with much of the Eastern forest in private hands, while Western forests are more public. Nationwide there is strong support—a January poll found that four out of five voters favor 30x30 objectives, while a majority (51%) already strongly favor the plan.

Shot by Nikole Turrell for Hothouse

What’s the relationship between conservation and restoration?

It’s the U.N. decade of ecological restoration and this emerging science has a huge role in carbon mitigation going forward, but it’s not magic.

In the first place, conservation is usually more cost effective and carbon effective than restoration. Pretty much whatever ecosystem you’re thinking of — wetlands, grasslands, coastal mangroves, forest — preventing development will be cheaper than trying to restore, after the fact, the ecological work done by those systems.

At the same time, there are vast tracts of degraded lands in need of rehabilitation — much of it declining or abandoned agricultural and forest land where a little bit of attention to biodiversity and hydrology could go a long way. “You need to restore the biosphere to a well functioning state. Not only for the climate system, but also for other element cycling—nitrogen, phosphorus, and so on,” says Steffen. “We need to completely refigure our societies to become much better stewards of the entire Earth system, which includes the biosphere.”

Restoration is a tricky business on a warming planet. “As the physical climate is changing, the ecosystem that may be adapted to the new climate may not be the one that was there pre-industrially,” Steffen says. “You're going to get a different ecosystem. You want to try to maintain well functioning ecosystems that play the maximum role in the biosphere in terms of habitat, carbon storage, biodiversity, and so on…. You need to have a robust biosphere to allow nature to evolve as the planet evolves, as it always has, which means you need a biodiversity rich system.”

What do you mean by conservation lands? Does my pollinator garden count?

While backyard rewilding projects contribute to biodiversity overall, they aren’t included in the 30x30 total. They do serve as buffer zones, genetic reservoirs, and wildlife corridors, and there is increasing support for this work. In July the Wildlife Corridors Conservation Act, which includes $400 million for projects to reduce wildlife-vehicle collisions, passed the United States House of Representatives as part of the INVEST in America Act.

“If you connect core areas, you have a higher survivorship of any individual species. Let's say one blinks out in one area. The ability for an animal to trot back over and reproduce and restart a population is much higher if there's connectivity,” says Jody Hilty, president and chief scientist of the Yellowstone to Yukon Conservation Initiative. “It actually may help to maintain the overall number of species in any core area.”

Can we possibly set that much land aside? What about the economy, and what about feeding people?

These are old arguments, and easily settled by the large body of work that suggests that the benefits of protecting at least 30% of the world’s land and waters outweigh the costs by a ratio of at least five to one. 

This sounds like one of those scenarios where government promises don’t quite match its achievements. What’s the track record so far?

In 2010 the Convention on Biological Diversity set a range of conservation goals called the Aichi Biodiversity Targets. While some progress was made, particularly on marine reserves, no targets were met, and the next round appears poised to repeat the same mistakes.

Will Steffen likes to tell the story of his Brazilian colleague Carlos Nobre, who was often asked about the Amazon tipping point and how close we could safely get to it. “He says we'll never know for sure,” says Steffen. “He said the only way we'll know for sure where that lies is by tipping it — and that's not a very smart thing to do. This is a risk game, and how much risk do you want to take? We've got to take this precautionary approach, which goes very much against the way a lot of economics and the political systems work. But we've got to change the way we think about these things.”

What can I do?

While conservation is a global issue, it matters most immediately at the local level.  “Get involved in local efforts,” says Jacob Malcom, director of the Center for Conservation Innovation for Defenders of Wildlife.  

Most people either live near or visit conservation lands. At federal, state, and many local levels, there are likely to be discussions about how to implement 30x30 as the policy works its way around bureaucratic and legislative hurdles. “Connect directly with decision makers and advocate for 30x30 and half-earth approaches,” Malcom says. “They're going to need input from local folks. People should get involved. They should speak up and say, Yes, set aside areas from any sort of development and help contribute to 30x30.”

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Hothouse is a weekly climate action newsletter written and edited by Mike Coren, Jemima Kiss, and Cadence Bambenek. Everything we publish is free to read — your donations fund our writers and artists.