Hot cows, less delicious wine: The problems food growers face with climate change
Twenty years ago, George Moss didn't often worry about planting trees to shade his cows. Cows in chilly Tokoroa didn't experience searing heat. Now, he's at the end of two extremely hot, dry, summers and he's started having meetings with a tree-planting company. "We are seeing significant change in the climate down here," he says. "We have had droughts, the daytime highs are getting higher and the winters are warmer than they were when we came down here 25 years ago." In 20 years, say Niwa climate projections , temperatures in Waikato, where Moss owns two dairy farms, will be 0.7-1.1 degrees Celsius hotter than they were in 1995. In 70 years, without cuts to emissions, Waikato could be up to 3.1C hotter. READ MORE: * Stuff to publish New Zealand's daily carbon count in print and online * Climate change adaptation as important as mitigation, MP Shane Jones says * Milking it: Work to clean water also curbs greenhouse gas emissions * Farms need drastic change to lessen climate change impact There'll be fewer frosts and more drought days in what is currently New Zealand's lushest dairy country - even if the world meets its carbon targets. Yet when Moss tries to plan for global heating, he struggles to balance a dizzying array of factors. Finances, cutting his own emissions, and working out what crops will grow in a future he can't yet imagine. "It's a wicked problem," Moss says. "You fix one thing and you blow out something else. We need help to find those win-wins." Such wins may be possible, according to a new report from two National Science Challenges , but only with careful planning now. The research, led by Anne-Gaelle Ausseil of Manaaki Whenua Landcare Research, found farmers and growers must adapt faster - or deal with lost production, heat-stressed cows and crop shortages. Beef, sheep and dairy farmers aren't the only ones who are vulnerable. Wine growers risk producing wine that doesn't taste as good as it once did, because some grape varieties will flower earlier. Depending on the farm or vineyard, adapting to climate change might mean planting different grape varieties, sowing maize for cow-feed earlier, changing fertiliser patterns, or protecting cows from over-exertion on hot days, the research says. (Cows cope better with cold than with heat). In some places, farming might have to cease. The key is to start planning early. But to do that, farmers need models that bring in the shifting climate, plant properties, environmental effects, water availability and finances. Those tools are not quite there yet. However, the latest report - from Our Land and Water and Deep South science challenges - shows it is possible to have a successful food-growing sector in a much more challenging climate. "The farming sector could be more resilient and profitable under climate change, if we use precision agriculture and give serious thoughts to what sectors we put in what places," says one of the authors, Waikato University freshwater scientist Troy Baisden. "You can see the possibilities, but we need to drill deeper in each particular region." BEEFY CHALLENGE Focusing initially on three regions - Waikato, Hawke's Bay and Southland - the researchers modelled 80 years of climate change to see what it would do to crop and grass growth. Baisden says they already knew that beef and sheep farms would be hit harder by climate change than would dairying - and the modelling confirmed that. The main reasons are that many dairy farms in dry regions are already irrigated, and they tend to use more fertiliser, making them better at coping with drought, says Baisden. "Dairy systems are simply more fertile, so they work better, even in a dry climate." The climate news was not all terrible for farmers, or people who enjoy eating New Zealand-grown food. Areas that were once too cool for grapes could become ripe for vineyards. Overall, the models found pasture growth around the country could stay about the same, but there would be winners and losers in different regions. Increased carbon dioxide and warmer winters could actually help grass grow in some places, despite drier summers. The maize many farmers grow to supplement cows' diets will grow in a shorter burst, earlier in the year, leaving time to plant wheat, oats or other crops in the same paddocks. On the other hand, animals will feel much more heat stress, so they'll need careful husbandry, including more trees to shade them, the research found. There will be more competition for fresh water for irrigation - especially in Waikato. In a blow to councils' struggling efforts to clean up pollution in lakes and rivers, the modelling also found that more extreme rainfall could worsen nitrates leaching from paddocks into waterways, particularly in Southland. "Many regions will experience a shift in seasons", says Baisden. "In Southland that's relatively positive, but in other areas, particularly the East Coast of the North Island, it's much more difficult. Finding feed for animals over summer and into autumn just gets a lot harder," he says. "The big question is whether farmers have the ability to adapt fast enough." For some, adapting may not be possible. Detailed modelling in Hawke's Bay showed that farmers in some remote areas would likely struggle to grow things. "The hill country areas are quite hard hit," says Baisden. WAY FORWARD The researchers hope their findings will be turned into detailed tools that farmers can use to visualise how they might use land in future. The Ministry for Primary Industries is exploring creating that kind of tool. Moss has already reacted to increased dry spells by planting deeper-rooted chicory in his paddocks, because it withstands droughts better than does ryegrass. He's stopped applying fertiliser during dry summers - it's pointless, since the grass won't grow without water. Researchers are using his land to test ways to shrink greenhouse gases. But he would love to see more detailed modelling, incorporating all the things he needs to think about as a farmer who wants to reduce his impact. "You've gotta develop a vision of what you want to do," Moss says. "Not only do we need to adapt to climate change, and adapt quite fast, but, morally speaking, we absolutely need to minimise our impacts on greenhouse gas and water," he says. "Yet at same time we're trying to maintain profitability. It's not easy, let me tell you."