Aug 8, 2019 4:00 AM

New IPCC Report Shows How Our Abuse of Land Drives Climate Change

Cutting out fossil fuels, which the IPCC has called for repeatedly, isn’t enough—we as a species need to fundamentally transform our relationship with the land.

Today brings yet another devastating report from the UN’s Intergovernmental Panel on Climate Change, this time outlining how humanity’s exploitation of land is contributing to climate change. The big takeaway: Cutting out fossil fuels, which the United Nations panel has called for repeatedly, isn’t enough. We as a species need to fundamentally transform our relationship with the land to stand any hope of fighting climate change.

“There are still people talking about, 'OK, well let's reduce our emissions quickly and then we'll be fine,'” says Janos Pasztor, executive director of the Carnegie Climate Governance Initiative, who wasn’t involved in the report. “We won't be fine. It's not enough.”

It’s not enough because cutting emissions doesn’t fix the broken systems that underlie it. This new report takes steps to quantify how our abuse of the land—deforestation, industrial agriculture, draining of carbon-capturing peatlands—is driving climate change, and in turn how that climate change is exacerbating the degradation of land the world over. It’s a vicious circle the human species has to break, and fast.

Take our unhealthy relationship with meat. Demand has skyrocketed in recent decades, in part because booming economies are bringing the poor into the middle class. That demand causes more land to be cleared for livestock, leading to deforestation. Fewer trees means less carbon gets sucked out of the atmosphere. The food supply chain also brings emissions, and the animals themselves emit the extremely potent greenhouse gas methane.

Crop production is problematic too. Nitrogen-based fertilizers—which have massively boosted crop yields over the past few decades—come with serious costs. Excessive use means nitrogen is running into rivers and lakes and oceans, leading to algae blooms that kill fish and block sunlight from reaching aquatic plants—another blow to carbon sequestration. On land, an excess of nitrogen is good for the crops that can metabolize it easily, but the majority of species can’t handle it. Native plants die out and biodiversity suffers, leading to a homogenous landscape. This, in turn, makes the landscape less able to sequester carbon, sacrificing yet another way to mitigate climate change.

The emissions that come from industrialized agriculture—tending the stuff with machinery, packaging it, and shipping it to consumers—are driving more warming that in turn threatens that agriculture. Extreme heat withers crops, fiercer rainstorms degrade fields, and rising seas erode farmland. Soil erosion from agricultural fields may be 100 times higher than the rate at which soil forms. (To help stop that, the report suggests techniques like encouraging the growth of cover crops, which help buffer the soil from those fiercer rainstorms.) Overall, food systems are becoming increasingly insecure.

The problem isn’t just with food. Climate change is altering the nature of land itself. As the planet warms, weather patterns change, and lakes and rivers dry up as desertification takes hold. This, the report warns, kicks off yet another feedback loop: Dry soils strengthen heat waves. Not helping matters is urbanization and the heat island effect—cities absorb solar energy throughout the day and slowly release it at night, leading to warmer evenings. Combined with more intense heat waves, like the one that hit Europe this summer, these higher urban temperatures threaten public health, particularly for the young and elderly. The heat island effect can also intensify extreme rain events, both over a city and in regions downwind.

On top of that, water insecurity presents a looming catastrophe on lands across the world, both for people and plants. Plants that dehydrate to death can’t help sequester carbon, so the report warns we need to get smarter about sustainable irrigation. And rainfall patterns are changing, often in surprising ways, which spells trouble for communities. In Southern California, for instance, models predict that climate change will bring fewer, yet more intense storms. So Los Angeles is preparing itself by building a rain catchment network to store those deluges underground for times of want.

Less developed communities around the world, however, won’t be so lucky. “Extended droughts have led to local collapses of populations, including collapses of major civilizations,” says Michael Kiparsky, director of Wheeler Water Institute at UC Berkeley, who wasn’t involved in the report. “So this isn't something that is just doom and gloom—it has happened in the past.” In today’s global economy, climate refugees might find outside help in the form of aid. But large-scale migrations can also trigger conflict. “The world is a crowded place,” Kiparsky adds. “Places with available land and water have by and large been settled. Rather quickly, climate disruption leads to social disruption.”

Underlying many of these issues is the problem of trees, which are often cut down for lumber or to make room for agriculture or livestock. When trees photosynthesize, they suck up CO2 and spit out oxygen, helping sequester our out-of-control emissions. Which makes Brazil’s accelerated culling of the Amazon all the more alarming.

The sequestration effect is particularly powerful in peatlands, peat being a top layer of slowly decaying organic matter (a precursor to coal) that stores carbon for perhaps thousands of years. But humans have been draining peatlands and replacing them with agriculture or urban development. Peatlands have also been drying out in the Arctic, which is warming twice as fast as the rest of the planet. This compacts them into a rich fuel for wildfires that burn for months at a time, releasing an astonishing amount of carbon into the atmosphere, leading to more warming and more dried peat to burn. Yet another devastating feedback loop between the land and the climate.

Supercharged wildfires elsewhere imperil communities. In California, for instance, climate change has created drier autumns, which unfortunately is the time of year when seasonal winds whip through the state. These fanned last year’s Camp Fire—which blew through the 30,000-person town of Paradise with such speed that many couldn’t escape. Eighty-five people perished, and nearly 20,000 structures were destroyed.

Now, the question is what to do about a problem as tangled as this one, which is touching practically every square inch of the planet. On the food side, technology can certainly help. Better refrigeration in the developing world and food coatings extend the life of foods, cutting down on waste. Genetically engineered crops might better withstand a warmer, drier world. Researchers can also tweak them to increase yields, which means farmers can use less land to produce the same amount of food, freeing up habitats to rehabilitate to their former glory.

Alternative protein options, such as lab-grown meat or plant-based meat, might help wean the developed world off livestock, at least partially. Even a relatively simple fix, like feeding cattle seaweed to cut down on their methane emissions (nearly half of humanity’s global methane output comes from agriculture and other land use), might help. “The more we can optimize feed for the health of the cow and milk production and methane emissions, that's the golden trifecta on the animal side,” says Gabe Youtsey, chief innovation officer of the University of California's Agriculture and Natural Resources division.

But all these ideas need to scale up massively to make a dent in climate change and restore some security to the food system that sustains all human life.

The report lays out the scientifically backed options for avoiding a coming collision between food and climate. For instance, rehabilitating tropical peatlands is a no-brainer. That will boost their carbon sequestration potential and bring back biodiversity that in turn brings in tourism. And tree-planting campaigns can restore lands that had been cleared for agriculture.

When done right, agriculture need not always be a threat to healthy forests. In Brazil, researchers are helping locals switch from cattle farming to cacao, which can grow in the shade, interspersed throughout a forest. Research has shown this technique can actually increase biodiversity and improve soil quality, as opposed to the old way of clear-cutting a forest to make room for grazing and farming. Everyone wins: People keep making a living, species keep their homes, and the forests keep sequestering carbon.

In a twisted way, by dumping massive amounts of carbon into the atmosphere, we’ve provided plants with more of the raw fuel to grow and absorb still more carbon. “But the important finding of this report, I think, is that this additional gift from nature is limited,” says Louis Verchot, a lead author of the report. “It's not going to continue forever. If we continue to degrade ecosystems, if we continue to convert natural ecosystems, if we continue to deforest, we continue to destroy our soils, we're going to lose this natural subsidy we're getting that's protecting us in part from ourselves.”

Where things get tricky, though, is with governance. The overarching issue is there’s not enough political outrage and action toward climate change. Even when there is action, many different parties are after the same goal—not destroying the planet and humanity along with it—but are coming at the solution from different angles. “We have environmental communities looking for decreasing biodiversity loss, we have communities looking at food production,” says Pasztor of the Carnegie Climate Governance Initiative. “It's like a Venn diagram of overlapping objectives, and we have to make sure the overlap is as big as possible and the negative tradeoffs are as small as possible. And this is not really happening.”

That will have to change, because we’re running out of time to both drastically cut emissions and reinvent our relationship with the land, as this new report makes abundantly clear. “We have solved complicated problems before in this world,” adds Pasztor, “and I have confidence this can be done too.”