The combination of accelerating climate shocks, land abuses and over exploitation of water resources, which is occurring at “unprecedented rates” across planet Earth, is undermining the ability of humanity to feed itself, the UN has warned.
In a global assessment released in Geneva on Thursday by the UN Intergovernmental Panel on Climate Change (IPCC), it concludes it will be impossible to keep global temperatures at safe levels unless there is also a transformation in the way the world produces food and manages land.
Prepared by 108 leading climate scientists from 52 countries, it says the window to address the threat is closing rapidly. A half-billion people already live in places turning into desert, and soil is being lost between 10 and 100 times faster than it is forming, it finds.
Among the measures put forward in the report is a proposal for a major shift towards vegetarian and vegan diets, which is will be controversial in the Irish context as the agriculture sector is hugely dependent on dairying and beef.
Attempts to solve the climate crisis by cutting carbon emissions from motor vehicles, heavy industry and power plants will be insufficient, it finds. Reducing emissions from agriculture and food production will be essential to keeping global warming well below 2 degrees, as committed to under the 2015 Paris Agreement.
"We're not telling people to stop eating meat. In some places people have no other choice. But it's obvious that in the West we're eating far too much," said Prof Pete Smith, a lead author and environmental scientist from Aberdeen University.
The impact of intensive agriculture – which has helped the world’s population increase from 1.9 billion a century ago to 7.7 billion today – has also increased soil erosion and reduced amounts of organic material in the ground and accelerated desertification. Land has been turned from an asset countering climate change by capturing carbon into a major source of greenhouse gas emissions.
Destruction of vast areas of tropical forest for ranches can be directly linked to global temperature increases, the IPCC finds, Such land abuses must be stopped to avoid catastrophic climate heating, the scientists conclude.
The imminent threat to global food production dominates much of the report, which took two years to compile. Humans now exploit 72 per cent of the planet's ice-free surface to feed, clothe and support Earth's growing population, the report notes. At the same time, agriculture, forestry and other land use produces almost a quarter of greenhouse gas emissions – in Ireland, farming is responsible for in excess of 33 per cent of emissions.
About half of all emissions of methane, one of the most potent greenhouse gases, come from cattle and rice fields, while deforestation and the removal of peat lands cause further significant levels of carbon emissions, it says.
These current problems are predicted to worsen as the global population is predicted to reach almost 10 billion by 2050.
"Climate change exacerbates land degradation through increases in rainfall intensity, flooding, drought frequency and severity, heat stress, wind, sea-level rise and wave action," the IPCC states.
The assessment coincides with confirmation of rising greenhouse gas emissions globally. In addition, Arctic sea-ice coverage reached near record lows for July – Alaska no longer has any ice within 150 miles of shore. Heatwaves that hit Europe last month were between 1.5 and 3 degrees higher because of climate change. Global temperatures for July were 1.2 degrees above pre-industrial levels for the month; the highest ever recorded while Kenya has already broken through the 1.5-degree level.
The IPCC warned last year that rises greater than 1.5 degrees risk triggering climatic destabilisation while those higher than 2 degrees make such events even more likely.
Dangerous tipping points
"We are now getting very close to some dangerous tipping points in the behaviour of the climate, said Bob Ward, policy director at the Grantham Research Institute on Climate Change and the Environment. The IPCC's latest work reveals, it is going to be very difficult to achieve the cuts we need to make to prevent that happening, he told the Guardian.
The report emphasises land will have to be managed more sustainably so it releases much less carbon. Peatlands will need to be restored by halting drainage schemes, while food waste will have to be reduced.
“The consumption of healthy and sustainable diets, such as those based on coarse grains, pulses and vegetables, and nuts and seeds… presents major opportunities for reducing greenhouse gas emissions,” it adds.
Policies need to include “improved access to markets, empowering women farmers, expanding access to agricultural services and strengthening land tenure security”, it states. “Early warning systems for weather, crop yields, and seasonal climate events are also critical.”
It also warns that plans by some governments to grow trees and burn them to generate electricity in an emerging bioenergy sector will compete with food production unless carried out on a limited scale.
The report offered a measure of hope by setting out pathways to address the looming food crisis. These incorporate a major re-evaluation of land use and agriculture worldwide as well as consumer behaviour. Proposals include increasing the productivity of land, wasting less food and persuading more people to shift their diets away from beef and other types of meat.