Humans Have Transformed 70% of Land on Earth. We Have a Choice for What We Do Next

By Brian Kahn on at

In what feels like it’s becoming a regular ritual in self-flagellation, scientists have released a new special report documenting the perilous state of our planet. The latest Intergovernmental Panel on Climate Change (IPCC) report focuses on how humans have transformed the very land we depend on for our survival.

If the planet warms beyond 2 degrees Celsius (3.6 degrees Fahrenheit) and we continue on the development path we’re on with extreme inequality and lack of global cooperation, the world could become a hellscape littered with food insecure regions, collapsed ecosystems, and entire swaths of the planet turned over to deserts. But as with other landmark reports on the extinction and climate crises, it neatly illustrates that we have the tools within reach to stop fucking the planet and society. We just need to pick them up and use them.

The report released on Thursday clocks in at 1,300 pages and is the work of about 100 of the world’s top scientists working in fields that cover climate change, diets, forests, and agriculture. The findings it lays out are stark about how we have terraformed the Earth.

Since 1961, the report finds, humans have used “unprecedented rates of land and freshwater” to accommodate now-7 billion and counting humans. That has translated to directly transforming 70 percent of all ice-free land. But every inch of land is being impacted by climate change. And because the air over land warms faster than the ocean waters, the land rate of warming is nothing short of shocking. The report notes that land has warmed twice as fast as the average temperature over land from 2006 to 2015 was 1.53 degrees Celsius (2.8 degrees Fahrenheit) warmer than the pre-industrial average. That means land – you know, the place where we live – has already left the relatively safe bounds of 1.5 degree Celsius threshold outlined in one of those recent jarring IPCC reports.

Of course, the 1.5-degree-Celsius threshold also matters for lots of ocean processes, like causing seas to rise through ocean expansion, so we’re still not technically over the limit. But the fact that we’ve passed it on land should give you and everyone else on Earth pause to think about the precipice we’re standing on.

The report further outlines how much of our tension with climate change runs through land. It’s a huge tug-of-war of competing interests and shifts, and human civilisation is right in the middle of them.

Human land-based activities have led to some of that warming. Agriculture and deforestation, in particular, have played a huge role in releasing greenhouse gas pollution. Land-use changes alone are responsible for 13 percent of global carbon dioxide emissions as well as 44 percent of methane emissions and 80 percent of nitrous oxide emissions. The latter two are greenhouse gases that are much more potent than carbon dioxide, and nitrous oxide also kills the ozone layer as if the climate impacts aren’t bad enough.

This toxic mix of pollutants, in turn, has altered the landscape. Heat waves have baked in drought, particularly in drylands. The report notes that desertification has advanced in drylands by about 1 percent annually from 1961-2010, and since 1980, 500 million people have experienced its wrath. Certain types of land use such as deforestation have exacerbated these climate trends, and most people who have had to contend with desertification are in developing countries in South and East Asia. The water crises that come with drought further reflect poor land management decisions.

At the same time, all the extra carbon dioxide has led to greening in some areas. And land still takes up a huge amount of the excess carbon dioxide human activities are dumping into the atmosphere, but the gravy train won’t last.

Illegal gold mines cut through the Peruvian Amazon. Photo: AP

“Land is important and it’s providing a gift to society in that it absorbs about 22 percent of the greenhouse gases we emit,” Louis Verchot, the landscape restoration theme leader at the International Center for Tropical Agriculture, said in a press call. “These are through natural processes. As we continue to pour more and more carbon dioxide in the atmosphere, the earth system absorbs more and more. This additional gift from nature is limited. It’s not going to continue forever.”

If we keep cranking up the heat on land, eventually its ability to take up carbon dioxide and other climate pollutants will fizzle. In addition, increasingly fierce fires like what we’re seeing in the Arctic this summer or California in recent years will dump some of that carbon dioxide back in the atmosphere. That will lead to further imbalances and crank up the heat even further.

This all ties back to the systems we rely on. I mean, obviously, we rely on Earth as a whole. But when it comes down it, humans require food, shelter, and mobility. These are all things we primarily rely on the land for. And as climate change ramps up, we’ll have a harder time accessing some of those things from the land. The report notes that “stability of the food supply is projected to decrease as the magnitude and frequency of extreme weather events that disruption the food supply chain increases.” That could cause food prices to spike (and in fact, some part of the world are already living with climate shocks to the food system).

But I started by telling you about our choices. And so let’s talk about them because the whole point of these reports isn’t to be a death knell for society. They’re written so world leaders and even the peons like you and I can make better decisions than the ones that got us to this place.

“There are a lot of actions available for us now,” Pam McElwee, a reporter author and human ecology at Rutgers who clearly must read Gizmodo, said in a call with reporters. “We don’t have to wait for some technological innovation.”

Chief among them are restorative agriculture practices that would turn around the trend of soil erosion, outlined in the report, that’s happening 10-20 times faster than new soil is being created. In real terms, that means planting cover crops, practicing no-till agriculture, avoiding profligate fertiliser application, and turning away from the whole factory farm thing.

For those of us who aren’t farmers, we can also make choices about our diets and food waste. The report estimates up to a quarter of all food grown doesn’t end up on plates. Research published earlier this year found that we could feed 9 billion people if we adjusted our diet to include less meat and fixed our broken agriculture system. Having eaten that diet, I can tell you it’s not that hard.

It also dips into some of the tradeoffs we could choose like whether we plant more forests that could sequester carbon while leaving less land to grow food.

“My argument would be natural climate solutions alone won’t get us where we need to be,” McElwee said. “When they’re combined with demand-side measures, that’s where we get the maximum benefits.”

None of this is to say the world will make the right choices or that it will all be great even if we do. The report uses modelled futures known as shared socioeconomic pathways of SSPs in nerd talk. In scenarios where we keep marching down the path we’re on, food insecurity becomes a “very high” risk concern along with swath of degraded land and acute water scarcity.

The sort of best-case scenario is dubbed SSP1, which the report notes is a world of 7 billion people with “high income and reduced inequalities, effective land-use regulation, less resource-intensive consumption, including food produced in low-GHG emission systems and lower food waste, free trade and environmentally-friendly technologies and lifestyles.” Sounds great!

Yet even then, the world would face a “high risk” of land degradation if the world warmed more than 2 degrees Celsius (3.6 degrees Fahrenheit). Still, it’s our best shot of a more functional planet and society. And time to get on track is running out.

“The window is closing rapidly on the world of SSP1,” McElwee said. “That’s a key message of this report.”

Featured image: Getty