Changing climate, changing Southern Hemisphere fruit industry
From floods to droughts to cyclones, the Asia-Pacific and Latin America have taken a battering from weather events in 2011, following the warmest year on record globally in 2010. While opinions differ on whether the phenomena are a result of human activity, one thing is clear – temperatures are rising and so is the incidence of extreme weather activity. At Freshfruitportal.com we speak to climate experts from Australia and Chile to gauge what is happening, and what might be in store for the fruit industry.
When asked about Australia’s extreme weather this year, The Climate Institute regional projects manager Corey Watts is quick to clarify his country ‘has always been a land of droughts and flooding rains’.
It is something Australian farmers know well, but Watts says with warmer temperatures the likelihood of extreme weather events is now much higher.
“It actually is accentuating those incidents. There are still parts of western and south-west Australia that are still in drought, even though we’re in a La Niña episode,” he says.
“We’re seeing more records being set for hot days and that can result in a reduction of harvests – prior to the 2008 bushfires there was a string of 40 plus degree days, new records were set, and those factors came together as a fire risk. Then the fires started.
“They have become so intense now that they’ve added two new categories; they’ve gone from just extreme to catastrophic. That presents quite a risk not just to people’s lives but to the horticultural industry; not just the direct impact from the fires but the infrastructure, overheating of crops.”
Watts points to the stone fruit industry as one of the biggest victims, due to a lack of frost when high temperatures are reached, but it’s not only crop volumes that are under threat. He says climate change will affect soil nutrients where fruit is grown, which will lead to changes in color and taste.
“Climate change increases the risk to plant health and it could also affect the color of the different fruits - this is one of the risks that have been suggested,” he says.
“If the nutrients are different the color will be different, and that can affect the marketing of the fruit, especially for the export market.”
A ‘Greater Intensity’
In the last 100 years global temperatures have risen by more than 0.7 degrees Celsius, while in the first nine months of 2010 the level of weather-related catastrophes was unusually high.
But is there a link between these events and climate change?
Queensland's peak horticultural body Growcom says there is, while many major international insurance companies like Munich Re and Swiss Re have announced the high incidence of natural catastrophes in 2010 cannot be explained without global warming.
“You’re getting more energy in the atmosphere because there’s more heat, and more moisture that’s been evaporating from the sea, and greater intensity in weather events,” says Watts.
“In the next 20 to 30 years droughts in south-east Australia that will require funding for farming will change from once in every 25 years, to once every two years. We’re seeing a present shift in the climate.
“Then there’s the strong Queensland floods and the affects of a hotter climate on the (farming) sector. In 2007 with Cyclone Tracy, crops were wiped out and you could see it in Sydney when people were stealing bananas to sell on the black market, they were so valuable.
“You had avocadoes and other industries that were struggling, and now you’ve had Yasi and the floods, there’s no doubt something’s happening.”
He says you can’t attribute each individual event to climate change but you can attribute their increased frequency and strength.
“Cyclones are growing in size, are more widespread than we’ve seen before, and while the Queensland floods were not as high as the 74 floods, they covered more of the state; that is mostly consistent the predictions made by scientists for the effects of climate change.
“Two months before the floods in Queensland a scientific panel warned that we would see a marked increase in torrential downpours as a result of climate change.”
Demand and beneficiaries
Watts highlights that not only will climate change pose a threat to many fruit growers, but the damage of catastrophic events could also affect consumption demand, which flows on to how much growers can sell.
“If people have lower disposable income as they’ve been affected by climate change, then that will affect industry too. If climate change affects competitors, some countries will be better off, but there will always be changes in this very tightly connected world,” he says.
“The temperature has risen but there’s also a rise in Carbon dioxide concentrated in the atmosphere, and no one really knows what that will do. Some think that carbon dioxide will have a beneficial effect on some crops, and they might be right. “
On the other side of the Pacific in South America, Chile’s drought has led the government to declare a state of emergency, while Peru too has experienced drought in many areas. Heavy rains in Argentina caused problems for its grape production this season, while Brazil recorded a record drought in the Amazon last year.
But rising temperatures have brought benefits to some regions, according to Agro-climate professor Fernando Santibañez from the Universidad de Chile.
“Progress has clearly been observed for some species around the south, like vines, pome fruit and cherry trees, where there are many private projects in the lake and river regions, including Aysen,” he says.
“For temperate countries, clearly climate change has pushed and will continue to push the lines of where some species can be cultivated in the south.
“Not to speak of Argentina, where there are regions that couldn’t grow soybeans but are today growing them, just because the rain has increased. It’s the same with cotton, which are growing in zones where they didn’t before.”
He explains that a slight increase in temperature can make some crops grow earlier, as seen in the difference between Copiapó and Santiago, where higher temperatures by two degrees means plants flower around one month earlier.
In terms of competitive advantage as the effects of climate change advance, Santibañez says the South American continent has two important buffers; the Amazon Rainforest combined with the cold Humboldt Current which runs up the Pacific coast from Antarctica.
“Firstly, the tropical forest still has a relatively large mass, which is not the case in Africa or on any other continent, so this is an important cushion to mitigate climate change in tropical areas – Latin America would have a much more difficult situation if it didn’t have the cushion of the Amazon Rainforest,” he says.
“In the temperate part, we have a large regulatory effect that’s called the Humboldt Current, which makes the ocean cold and prevents large increases in temperature or other extreme events associated with climate change.
“We’re pretty far from having more heat waves and cold snaps like those in Europe and the United States, we’ll hardly get those problems here, and presumably our hikes in temperatures are not going to be in the same magnitude of what is going to happen in the Northern Hemisphere – we have a privileged position in the world because of this.”
The effects of aridity
While it may have a relative advantage, South America’s climate situation is far from perfect. While growers in Chile’s south can now grow some crops more easily, the northern zone has suffered.
“In Chile we can say good things have happened in recent decades, for example horticulture, but climate change has been wiping out some crops in the north such as wheat, which is now impossible to grow in the IV region on the coast,” he says.
“Chile produced wheat in that area for 200 years, but as the farmers themselves say, it’s simply not viable, it’s impossible.
“These are very gradual events, changes we observe very slowly and therefore it is not easy to identify an immediate and direct impact for a significant agricultural phenomenon, but in general we can say there clearly has been increased climate variability and that is absolutely proven.”
He says the extreme events in Chile alternate between dry and wet years more abruptly, between La Niña and El Niño periods.
“In Latin America, even more than in Chile, there are studies showing that the number of such destructive storms have increased fivefold in some regions of Latin America,” he says.
“The number of drought episodes and also fires due to extreme weather events have increased by more or less threefold. There are precedents, records, verifiable observations that show in the last two decades we have begun to deal with a hostile climate.”
Santibañez says high rainfall runoff has caused erosion problems in Chile’s northern and central zones, so the fruit industry needs to introduce more soil protection systems, like vegetative cover and run-arrest systems, especially for avocado crops on slopes.
He says there are many tasks ahead, as climate change will exacerbate Chile’s water problems.
“With climate change it could be that renewable water systems diminish their ability to produce water, such as the mountains – all the models say they should be less able to produce water and river flows to some basins will fall by 10, 20, 30 per cent.
“Therefore the number one task to adapt to these conditions is a program for efficient use of water resources, involving works in river water regulation, water harvesting system, water infiltration systems to recharge groundwater and high efficiency irrigation technology.”
Risk to future generations
Watts says one of the most unfortunate aspects of climate change is that the horticulture industry has contributed very little to carbon dioxide emissions, yet it will affected by changing weather conditions so much.
“The carbon footprint of the horticulture industry is low so in a sense they are the victims of other people’s pollution. It’s good that Growcom has come out and said, this isn’t good enough.
“The increased risk of this will be borne by future generations, and what we’re doing is making life much harder for them. Some people think it’s either adapt or mitigate, but there’s no reason why you can’t have both.
“There is a choice between the amount of adaptation, mitigation and suffering; all of these things are inevitable, and unfortunately that includes suffering, but we can act to mitigate the effects of climate change".