Humanity will have to manage land more efficiently to avert a climate breakdown, a United Nations scientific report warns. Growing human pressure is already degrading land globally and climate change is adding to these pressures, it said.
Crucially, better land management alone will not be enough to solve the problem. It has to go hand in hand with efforts to reduce greenhouse gas emissions if global warming is to be restrained well below 2 degrees Celsius, the report said.
The Special Report on Climate Change and Land (SRCCL) was prepared by the Intergovernmental Panel on Climate Change, a collection of international scientists brought together by the United Nations to assess the science related to climate change. Its summary was approved by the world’s governments on Wednesday in Geneva and released on Thursday to the media.
The extent and rate at which humans have been exploiting land and freshwater resources is unprecedented in history, the report says. Together with intensified land use, that exploitation has already led to a loss of biodiversity and ecosystem services and has hastened land degradation and desertification, impacting the livelihoods of millions of people.
As the global population increases, land must remain productive to maintain food security. Yet the negative impacts of climate change on vegetation are increasing, said the report, and land's contribution to climate change mitigation measures, such as afforestation and the growth of energy crops, is limited. Bioenergy needs to be carefully managed to avoid risks to food security, biodiversity and land degradation.
Land and Human Activity
The use of land for practices such as agriculture and deforestation affects 75% of the Earth’s land surface, causing widespread land degradation. Changes in land use over the past century already cause as much as 23% of manmade greenhouse gas emissions, and accelerating changes in the climate will have widespread impacts on land. Although land is still a net absorber of carbon, it is possible that climate change will damage soils to the extent where it becomes a net emitter of carbon.
“Land already in use could feed the world in a changing climate and provide biomass for renewable energy, but early, far-reaching action across several areas is required,” said Hans-Otto Pörtner, Co-Chair of the IPCC working group that assesses the vulnerability of socio-economic and natural systems to climate change. Action is also required "for the conservation and restoration of ecosystems and biodiversity,” he added.
The IPCC report has been in the making for more than two years and offers the most comprehensive assessment of the linkages between the breakdown in the climate and the way humans use land, including for agriculture and forestry.
“Governments must unite behind the science. They must now substantially increase their national climate targets by 2020 in line with the 1.5 degree Celsius pathway and cut global emissions by half within the next decade,” the Climate Action Network, a global platform of non-governmental organisations, said in a statement in response to the report. “Nature-based solutions must go together with abandoning fossil fuel use and investing in renewables. This report must form the basis for a renewed political conviction to respond to the climate crisis.”
The IPCC report on land is the latest in a series of alarming scientific reports on the impacts of global warming on humanity and natural ecosystems.
The first global assessment of biodiversity and ecosystem services, released in May this year, held humans largely responsible for a looming mass extinction of species and urged immediate action to avert disaster. The rate of species extinction is accelerating, with grave impacts on people around the world, warned the report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).
While more food, energy and materials than ever before are now being supplied to people in most places, it is increasingly at the expense of nature’s ability to provide such contributions in the future and frequently undermines nature’s many other contributions, the IPBES report said.
Earlier, in October 2018, the IPCC released another special report — Global Warming of 1.5 degrees Celsius — that said “rapid, far-reaching and unprecedented changes in all aspects of society" were required to keep global warming from rising 1.5 degrees above preindustrial levels. An inability to do so could result in runaway climate change, it noted.
The IPCC report on land use reiterates that there is an ecological and climate change emergency in the making by showing how the use of land is worsening the climate crisis.
“Food security will be increasingly affected by future climate change through yield declines — especially in the tropics — increased prices, reduced nutrient quality, and supply chain disruptions,” said Priyadarshi Shukla, Co-Chair of the IPCC working group focused on climate change mitigation. “We will see different effects in different countries, but there will be more drastic impacts on low-income countries in Africa, Asia, Latin America and the Caribbean.”
To avert a climate breakdown, the authors of the report urged the world’s governments to rapidly transform land use and food systems and halt deforestation.
Reduce Food Waste
About a third of global food production is lost or wasted, the IPCC report said. Drastically cutting food waste and switching to more plant-based diets, particularly in societies with high greenhouse gas emissions, while also promoting agro-ecological farming, will go a long way toward curbing emissions and strengthening adaptation, it added.
“This report sends a clear message that the way we currently use land is contributing to climate change, while also undermining its ability to support people and nature. We need to see an urgent transformation in our land use,” said Stephen Cornelius, Chief Advisor on Climate Change and IPCC lead at WWF. “Delayed action will increase the risk of climate change impacts on food security. Those most at risk are the world’s poorest.”
Experts emphasised nature-based solutions to the climate crisis and linked the current problem with the biodiversity crisis. There is a major role for conservation, restoration of natural ecosystems and prioritisation of forests, they said.
“Farming must work with nature, not against it,” said Teresa Anderson, Climate Policy Coordinator at ActionAid International. “A major shift to farming methods that work with nature, reduce emissions, empower women farmers and improve resilience to the impacts of climate change is now essential."
Banner photo: Degraded land cannot support life / Credit: Erce Tumerk via Flickr