environment

Farmers among biggest victims of climate change

Food waste, soil erosion, deforestation and, yes, methane from cows feature in a major IPCC report on land. Farmers emerge not only as contributors to climate change, but some of its most significant victims.

Farming needs to change to help save the climate - but if other emitters don’t slash their carbon outputs to save the climate and, consequently, farming, our food supply will be in trouble. 

The IPCC’s Special Report on Climate Change and Land is the first time the global network of scientists has looked at land use and climate change in the broadest sense, and the authors have warned that food security will suffer if global warming overshoots 1.5C or, especially, 2C.

The report makes clear that much of the onus is on industrial, transport and other emitters to urgently cut greenhouse emissions to give food growers the friendly climate they’ll need to feed a growing and increasingly affluent global population.

Agriculture itself is in a tricky position: its existence as an industry is non-negotiable if people are going to continue to eat.

But the way people use land currently is responsible for about 23 percent of global emissions, counting both deforestation and farming emissions. That figure is higher - up to 37 percent - if emissions from the whole food system are counted.

The report lists the numbers: Agriculture creates the lion’s share of nitrous oxide (82 percent), almost half of methane (44 percent) and 13 percent of carbon dioxide. Those emissions are rising and projected to rise further, as the global population grows and gets wealthier - changing its diet accordingly.

On the other hand, land (and the plants we grow on it) is a huge natural sink for emissions, absorbing the equivalent of 29 percent of total CO2 emissions, the report says.

The pressing problems of climate and land use described in the report are often circular. For example, global heating worsens land’s contribution to further heating, because soils have reduced capacity to act as sinks for carbon sequestration at higher temperatures.

There are plenty of solutions suggested: increasing soil carbon, rescuing peatlands from destruction and farming more sustainably can help the climate while allowing more food to be grown on less land. Efficient farming of more nutritious food can leave more room for land to grow carbon-sucking forests and more bioenergy crops. (Although using too much land for bio-energy could create its own problems, the report says.)

The key message for people using - and making policy about using - land is that there is no path to keeping inside 1.5C or even 2C warming that does not involve significant help from agriculture and forestry.

And for other emitters, cutting carbon and saving land's food-growing functionality is crucial for everyone's benefit: “Deferral of greenhouse gas emissions reductions from all sectors implies trade-offs including irreversible loss in land ecosystem functions and services required for food, health, habitable settlements and production, leading to increasingly significant economic impacts on many countries in many regions,” says the summary.

And farmers emerge from the report as climate victims in the most serious sense. Many farmers live in countries where per-capita emissions are negligible, and many of those same countries are most at risk from desertification, dust storms, heat waves and reduction in crop yields. Even cows do not do well outside their comfort range of temperatures.

The summary for policymakers - aka the more digestible version that's released for politicians and other non-scientists - highlights several pressing issues, some of them particularly relevant here in New Zealand.

Here are our five top takeaways.

1. Yes, you can still eat meat (but the environmental costs of food must be factored in).

There were rumblings online that the IPCC might be about to launch a major push for global vegetarianism or veganism. Of course, it hasn’t, but the report gives a nudge towards “plant rich” and “balanced diets” based on national nutritional and health guidelines.

Animal products have a place in global diets, the report envisages, but they must be grown sustainably and with low greenhouse gas emissions.

And all food should reflect the environmental costs of growing it, the report says (while acknowledging it's not yet always easy to measure the environmental damage represented by an end product).

Animal agriculture features in several of the less promising statistics. Methane, for example, has been rising since 2007 after a lull in growth. Biological methane from farming makes up a larger proportion of methane emissions (relative to methane from the fossil fuel industry) than it did before 2000. “Ruminants and the expansion of rice cultivation are important contributors to the rising concentration,” says the summary.

Nitrous oxide is also rising, with poorly-managed and over-applied fertiliser cited as a major source. Also, animal poop. “There has been a major growth in emissions from managed pastures due to increased manure ... Livestock on managed pastures and rangelands accounted for more than one half of total anthropogenic N2O emissions from agriculture in 2014."

In a statement accompanying the report, Debra Roberts, a co-chair of one of the IPCC working groups, said: “Balanced diets featuring plant-based foods, such as coarse grains, legumes, fruits and vegetables, and animal-sourced food produced sustainably in low greenhouse gas emission systems, present major opportunities for adaptation to and limiting climate change.”

By 2050, dietary changes could free several million square kilometres of land and prevent between 0.7 and 8.0 gigatonnes of carbon dioxide a year from entering the atmosphere, compared with business as usual, says the summary.

The focus on healthy, plant-centred diets and sustainable meat and dairy might not be a bad thing from New Zealand’s perspective as an exporter.

When the authors of the IPCC land report met in Christchurch last year, several of them talked about the need to shift away from high rates of meat consumption in the developed world, and how the growing world population could not eat the way people in many developed nations currently do.

But they also said New Zealand might be well-placed in a global push to make food more nutritious and sustainable, if farmers could claim to grow the climate-friendliest, most sustainable dairy and meat around.

Diet's not the whole picture of food consumption, though. 

One of the most bracing figures in the report is about food waste. While it's not the first time it has been said that a third of food produced is wasted or lost, the report stresses the climate consequences of this: food lost and wasted is responsible for 8-10 percent of all human-made greenhouse emissions - emissions that were produced in the service of feeding absolutely no one.

The problem is complex and different in each country, but the summary seems to point to this as an obvious area for action.

2. Pukekohe's problem is everyone's problem

New Zealand is pretty well aware of its problem with a growing Auckland, which is diligently gobbling up the best productive soil in the nation under subdivisions and lifestyle blocks.

The report highlights this as a problem globally, as cities grow - often out, instead of up.

“Urban expansion is projected to lead to conversion of cropland leading to losses in food production ... This can result in additional risks to the food system. Strategies for reducing these impacts can include urban and peri-urban food production and management of urban expansion."

Cities are not the only risks to soil.

Right now, soil erosion from agricultural fields is estimated to outstrip the rate of soil formation by 10-100 times, depending on whether the soil is tilled (tilling loses more soil).

As droughts and deluges increase in frequency and intensity, soil will suffer at both extremes. Too dry, and the land erodes or becomes desert. Too much rain and cropland erodes, as well.

Climate change is projected to increase both extreme dry and extreme wet. The summary suggests better land planning rules, farming methods that reduce tilling and employ cover crops (to defend soil between harvests), and farming in ways that help build up organic carbon in the soil - as well as, obviously, combatting climate change to reduce climate extremes. 

3. Plants are already on the move, and food security may suffer

Like sun-seeking, jet-setting retirees, the plants we eat will travel to follow their preferred climates. Changing conditions mean some latitudes are already getting more productive for some crops, but others are seeing falling yields – and the net outcome is more risk to the food supply.

The report's summary says climate change has already affected food production due to warming, changing rainfall patterns, and greater frequency of some extreme events – and while yields of maize, wheat and sugar beets have increased in high latitudes, yields of maize and wheat have declined in other parts of the globe.

How much things change from now depends largely on emissions.

“New knowledge shows an increase in risks from dryland water scarcity, fire damage, permafrost degradation and food system instability, even for global warming of around 1.5°C ,” says Valérie Masson-Delmotte, another working group co-chair. “Very high risks related to permafrost degradation and food system instability are identified at 2°C of global warming.”

Cynthia Rosenzweig, a senior climate scientist at the NASA Goddard Institute for Space Studies, and one of the report's authors, told Newsroom when she was in New Zealand last year, the net outcome of global heating was less food: “When we do these rigorous multi-model projections, what we find is that in the mid- and high-latitudes, things could get better for some decades, as those regions warm. But in the lower latitudes, where primarily the developing countries are, food production is projected to decrease. When we take these results and feed them into the economic models, we find that, overall, globally, there’s a decline in production and an increase in food prices,” Rosenzweig said last year. “We look at the 2020s, 2050s and 2080s and it basically gets progressively worse. It just gets hotter and we get more heavy rainfalls and more droughts, all of which affect agriculture.”

As for the details of what else climate change can do to food-growing land, it’s hard to put it better than the summary itself:

- “With increasing warming, the frequency, intensity and duration of heat-related events including heat waves are projected to continue to increase through the 21st century ...The frequency and intensity of droughts are projected to increase particularly in the Mediterranean region and southern Africa [and] the frequency and intensity of extreme rainfall events are projected to increase in many regions," it says.

- “With increasing warming, climate zones are projected to further shift poleward in the middle and high latitudes.”

- “In drylands, climate change and desertification are projected to cause reductions in crop and livestock productivity ... modify the plant species mix and reduce biodiversity.”

- “The stability of food supply is projected to decrease as the magnitude and frequency of extreme weather events that disrupt food chains increases.”

- “Increased atmospheric CO2 levels can also lower the nutritional quality of crops.”

There might also be higher food prices, depending how we manage things, the summary adds.

4. The vulnerable are most at risk

One of the potentially deadly ironies of climate change is that those who've made the least emissions are in line for worse effects. 

Fittingly, this is the first IPCC report of which the majority of authors – 53 percent – are from developing countries.

The summary says that, within populations, women, the very young, elderly and poor are most at risk of effects of climate change on land.

Food insecurity will hit hardest in many parts of the world where agriculture is already tough.

“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, a third working group co-chair. “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.”

Drought-stricken land has been increasing already, and there are about 500 million people living in areas with a desertification problem, mainly in South and East Asia, around the Sahara, and the Middle East.

Notable mention goes to one wealthy country at risk from desertification, though: Australia warrants a namecheck in the list of areas where desert is spreading because of increased temperatures and less rain. 

Desert growth is, unhelpfully, also another a fueler of climate change, because of the loss of plants that would have absorbed carbon. 

5. What now?

Now that world governments have signed off the report, it will be used in future discussion on government climate action.

The scientific findings will be cited in upcoming negotiations, such as the Conference of the Parties of the UN Convention to Combat Desertification (COP14) in New Delhi in September, and the UN Framework Convention on Climate Change Conference (COP25) in Santiago in December.

The land report is the second of three special IPCC reports that will be released between the inter-governmental body's sixth and fifth full assessments.

(The first special report was on staying within 1.5C, the third will be on oceans and the cryosphere. Another special report, on climate change and cities, is due after the sixth full IPCC assessment report in released in 2022.)

In the meantime, the report is sprinkled with actions that could be taken now to help the climate, and land.

An incomplete list:

- Better forest management, stopping destruction of old forests.

- Farming to sequester more organic carbon in the soil, tilling less, using cover crops, using fertiliser more carefully.

- Regulation: better land use zoning, spatial planning, and incentives (such as payment for ecosystem services).

- Incentives for environmental farm planning, standards and certification for sustainable production.

- Planting trees over badly-degraded or eroding soil. Combining farming and forestry on the same land.

- Saving remaining peatlands, mangrove areas and wetlands from being drained,

- Wasting less food by better harvesting techniques, on-farm storage, infrastructure, transport, packaging, retail and education.

- Changing diets to better follow public health guidelines. 

- Not converting grasslands to crops.

- Better grazing management on sheep, beef and dairy farms to defend the soil.

- Growing more diverse crops and animal products to guard against climate risk.

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