The Guardian (USA)

Meat, dairy and rice production will bust 1.5C climate target, shows study

- Damian Carrington Environmen­t editor

Emissions from the food system alone will drive the world past 1.5C of global heating, unless high-methane foods are tackled.

Climate-heating emissions from food production, dominated by meat, dairy and rice, will by themselves break the key internatio­nal target of 1.5C if left unchecked, a detailed study has shown.

The analysis estimated that if today’s level of food emissions continued, they would result in at least 0.7C of global heating by the end of the century, on top of the 1C rise already seen. This means emissions from food alone, ignoring the huge impact of fossil fuels, would push the world past the 1.5C limit.

The study showed that 75% of this food-related heating was driven by foods that are high sources of methane, ie those coming from ruminant livestock such as cattle, and rice paddy fields. However, the scientists said the temperatur­e rise could be cut by 55% by cutting meat consumptio­n in rich countries to medically recommende­d levels, reducing emissions from livestock and their manure, and using renewable energy in the food system.

Previous studies have shown the huge impact of food production on the environmen­t, particular­ly meat and dairy, but the new study provides estimates of the temperatur­e rises their emissions could cause. These could be a significan­t underestim­ate, however, as the study assumed animal product consumptio­n would remain level in the future but it was projected to rise by 70% by 2050.

“Methane has this really dominant role in driving the warming associated with the food systems,” said Catherine

Ivanovich, at Columbia University in the US, who led the research. “Sustaining the pattern [of food production] we have today is not consistent with keeping the 1.5C temperatur­e threshold. That places a lot of urgency on reducing the emissions, especially from the high-methane food groups.”

“We have to make the goal of sustaining our global population consistent with a climate-safe future,” she said.

The contributi­on of global food production to the climate crisis is complex because it involves several important greenhouse gases, all of which have different abilities to trap heat and persist in the atmosphere for different amounts of time. Previous studies have converted the impact of methane and other gases into an equivalent amount of CO2 over 100 years, but this underplaye­d the high potency of methane over shorter timescales.

The research, published in the journal Nature Climate Change, treated each greenhouse gas separately for 94 key types of food, enabling their impact on climate over time to be better understood. Feeding this emissions data into a widely used climate model showed that the continuati­on of today’s food production would lead to a rise of 0.7C by 2100 if global population growth was low, and a 0.9C rise if population growth was high.

“As we had already reached more than 1C warming above pre-industrial levels by 2021, this additional warming [from food production] alone is enough to surpass the 1.5C global warming target,” the scientists concluded. “Our analysis clearly demonstrat­es that current dietary production and consumptio­n patterns are incompatib­le with sustaining a growing population while pursuing a secure climate future.”

Food-related temperatur­e rise could be curbed, the researcher­s said. If people adopted the healthy diet recommende­d by Harvard medical school, which allows a single serving of red meat a week, the rise could be cut by 0.2C. Such a diet would mean a big cut in meat eating in rich nations but could mean an increase in some poorer countries.

Cutting methane emissions from cattle using feed additives and better management of manure could avoid another 0.2C, the researcher­s said, while switching to green energy in the food system would cut 0.15C. Ivanovich said the emissions reductions options included in the study were those possible today but that future technologi­cal advances might be able to reduce emissions further.

“We already know that livestock production has a disproport­ionate contributi­on to climate change – even using traditiona­l metrics, in 2021 we showed that 57% of emissions from the food system arise from animal agricultur­e,” said Prof Pete Smith, at the University of Aberdeen, UK. “This very neat study uses a simple climate model to show the disproport­ionate impact of methane emissions from agricultur­e on temperatur­e increases, and throws light on the importance of reducing methane emissions from the food system.”

Only a third of the world’s countries have included policies to cut emissions from agricultur­e in the climate plans they have submitted under the UN Paris agreement. The researcher­s said their work was aimed at increasing the understand­ing of the impact of global food consumptio­n on future global heating. Ivanovich also said policies to cut emissions had to protect access to food and livelihood­s for vulnerable population­s.

would give up such an advantage, but there’s weakness of that world: it’s an unstable one. Being a gatekeeper only works while there is a fence around your product, and it only takes one company to decide (willingly or not) to make something almost as good available for free to blow a hole in that fence for good.

The other world is one where the AI models that define the next decade of the technology sector are available for anyone to build on top of. In those worlds, some of the benefit still accrues to their developers, who are in the position to sell their expertise and services, while some more gets creamed off by the infrastruc­ture providers. But with fewer gatekeeper­s in play, the economic benefits of the upheaval are spread much further.

There is, of course, a downside. Gatekeeper­s don’t just extract a toll – they also keep guard. OpenAI’s API fees aren’t a pure profit centre, because the company has committed to ensuring its tools are used responsibl­y. It says it will do the work required to ensure spammers and hackers are kicked off promptly, and has the ability to impose restrictio­ns on ChatGPT that aren’t purely part of them model itself – to filter queries and responses, for instance.

No such limits exist for Stable Diffusion, nor will they for the pirate instances of LLaMA spinning up around the world this week. In the world of image generation, that’s so far meant little more than a lot more AI-generated porn than in the sanitised world of DallE. But it won’t be long, I think, before we see the value of those guardrails in practice. And then it might not just be Meta trying to jam the genie back in the bottle.

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 ?? Photograph: David Litschel/Alamy ?? A cattle farm in central California, US. If people adopted the Harvard healthy diet, which allows a single serving of red meat a week, the rise could be cut by 0.2C.
Photograph: David Litschel/Alamy A cattle farm in central California, US. If people adopted the Harvard healthy diet, which allows a single serving of red meat a week, the rise could be cut by 0.2C.

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