The big change Australia needs to make
People's eating habits are making them unhealthy as well as contributing to global warming that will eventually drive up the price of food.
The latest report from the Intergovernmental Panel on Climate Change (IPCC) shows how much people's diets are contributing to climate change and how changing these could make them healthier as well as address global warming.
The report released today noted the mean land surface air temperature increased by 1.53C between 1850/1900 and 2006/15, which is double the global mean surface temperature of 0.87C.
The Paris Climate Agreement aims to cap global warming at "well below" 2C above pre-industrial levels. The year 2018 was about 1C above it.
"We are already feeling the impacts of climate change, especially in summer with repeated heatwaves" IPCC vice chair Professor Mark Howden of the Australian National University told news.com.au.
"Climate change is already impacting our land systems, our agriculture, forests and biodiversity," he said. "Those impacts will increase significantly in the future."
About 29 per cent of greenhouse gas emissions globally come from the food system but changing this could make people healthier and better off.
"The good news from this report is that we don't have to make a choice between feeding ourselves and living in harmony with nature - solutions that ensure food security are also good for nature, the climate and communities," Australian Conservation Foundation president Mara Bún said.
But food security is at risk if the world doesn't act quickly to tackle climate change.
"This report shows climate change is creating additional stresses on our land, increasing the risks to affected communities and industries of extreme weather events, erosion and fire damage," ACF board member Garry Gale said.
Mr Gale said Australian search was pointing to promising solutions but these would only be commercially viable if governments invested in them, banks and insurers also backed the projects.
"We need to make it easier for farmers to take up precision agriculture - only using what you need - and make their properties wildlife friendly."
Australia's action on climate change so far has been blocked by partisan political challenges and Prof Howden said the country was missing out on opportunities.
"Other countries who are more proactive on climate change are actually making good money out of it," he said. "Whether that is Denmark with its wind turbines or China with its solar panels. There are significant opportunities to being ahead of the curve … at the moment we haven't got an eye on the ball at all and I think that's a huge opportunity that's being missed."
However, if Australia can change the way it manages land, along with changing how people eat and reduce food waste, this could help reduce climate change as well as benefit Australians financially and physically.
CHANGING OUR DIETS
The way that we eat has changed a lot since 1961 and it's not agreeing with us.
Since 1961 the supply of vegetable oils and meat per person has more than doubled and the supply of food calories has increased by about 30 per cent.
On top of this, about 25-30 per cent of the food produced is lost or wasted.
Not only have these factors contributed to extra greenhouse gas emissions, two billion adults are also now overweight or obese, while an estimated 821 million people are undernourished.
Climate change could also make us unhealthier, as higher carbon dioxide levels in the atmosphere lower the nutritional quality of crops.
Economic models are also predicting food prices could rise due to climate change, with cereal prices projected to increase by about 7.6 per cent in 2050.
Encouraging people to eat a more balanced diet could reduce pressure on the land and improve people's nutrition, providing significant health benefits.
Dietary changes would involve eating more plant-based foods, including coarse grains, legumes, fruits and vegetables, nuts and seeds, as well as animal products produced in sustainable and low emissions systems.
By 2050, changing dietary habits could free up several million square kilometres of land and potentially reduce emissions by up to eight billion tonnes of equivalent carbon dioxide a year.
Another shocking fact is the sheer amount of food we are wasting.
Currently about 25-30 per cent of the food produced is being lost or wasted.
The waste is so high that it contributed to 8-10 per cent of human-caused greenhouse gas emissions between 2010 and 2016.
The reasons for food waste vary between developed and developing countries as well as between regions.
But there are options to improve harvesting techniques, on-farm storage, infrastructure, transport, packaging and retail industries. Better education can also reduce food loss.
By 2050, reduced food loss and waste could free up several million square kilometres of land.
The use of bioenergy, such as fuels like ethanol made from plants and other organic sources, will likely play a part in keeping global warming to 1.5C.
The report suggested most pathways to keeping warming to 1.5C include substantial use of bioenergy technologies.
The scale of this industry is staggering.
Up to seven million square kilometres of land could be for bioenergy by 2050, which is equivalent to the size of Australia.
While there are other options that don't involve using as much bioenergy or other carbon dioxide removal options, these pathways rely on faster changes to energy, land, urban systems and infrastructure, as well as behavioural and lifestyle changes to limit warming to 1.5C.
However, the report also noted the production and use of biomass for bioenergy can have adverse side effects, and risks for land degradation, food insecurity, greenhouse gas emissions. This will depend on factors like the initial land use and the climate of the region.
CHANGING HOW WE FARM
In many ways farmers have the most to lose from climate change.
As global warming gets worse, it can exacerbate land degradation through increases in rainfall intensity, flooding, drought frequency and severity, heat stress, dry spells, wind, sea-level rise and wave action and permafrost thaw.
Urban expansion is also projected to see more forests converted to cropland but this could actually worsen climate change and losses in food production.
Changing farming practices can make land more productive as well as reducing greenhouse gas emissions.
The report suggests many technologies and practices are profitable within three to 10 years.
The cost of introducing new practices can range from about $US20 ($29.50) per hectare to $US5000 ($7383) per hectare. The median cost is estimated about $US500 ($738) a hectare.
Despite the cost, introducing these changes can improve crop yields and the economic value of pasture.
Practices for cropland can include increasing soil organic matter, erosion control, improved fertiliser management, improved crop management, for example, paddy rice management, and use of varieties and genetic improvements for heat and drought tolerance.
For livestock, options include better grazing land management, improved manure management, higher-quality feed, and use of breeds and genetic improvement.
GROWING OUR SINKS
Restoring forests do not store carbon indefinitely as they are susceptible to fire or logging but maintaining peatlands can continue to sequester carbon for centuries provided they are not disturbed by things like flood, drought, fire, pest outbreaks or poor management.
Climate change exacerbates land degradation, particularly in low-lying coastal areas, river deltas, drylands and in permafrost areas.
From 1961 to 2013, the annual area of drylands in drought has increased, on average by slightly more than 1 per cent a year.
In 2015, about 500 million people lived in areas that experienced desertification between the 1980s and 2000s.
The highest numbers of people impacted were in South and East Asia, the Sahara region including North Africa, and the Middle East including the Arabian peninsula.
WE MUST ACT NOW
Acting now may avert or reduce risks and losses, and generate benefits to society.
It could reduce the risk to millions of people from climate extremes, desertification, land degradation and food and livelihood insecurity.
But if action is delayed, some options such as increasing organic carbon (like compost) in the soil may not be as effective because soils have less capacity to act as sinks for carbon storage when temperatures are higher.
It may also lead to irreversible loss in ecosystem functions and services required for food and other production, leading to increasingly significant economic impacts.
"Delaying action as is assumed in high emissions scenarios could result in some irreversible impacts on some ecosystems, which in the longer-term has the potential to lead to substantial additional greenhouse gas emissions from ecosystems that would accelerate global warming," the report said.