In the fresh produce industry we can no longer bury our heads in the sand. Climate change is already bringing its effects to bear on production in the UK, the Mediterranean basin and elsewhere with clear implications for the trade.
Just last week, the National Farmers’ Union published its own thorough and dispassionate research on the issue with the conclusion that the UK needs a government minister to co-ordinate action and oversee change across society.
“The role of agriculture and horticulture in combating climate change must bring about a radical change in their relationship with government, society and the environment,” says Richard Hirst, chairman of the NFU’s horticulture board. “Horticulture and agriculture in the UK can, uniquely, affect the management of the land, the environment and climate. We already provide produce with low food miles and a commitment to the environment. Both horticulture and agriculture can further tackle climate change through substituting fossil fuels, continued energy efficiency and carbon sequestration.”
Clearly businesses are going to have to adapt to the changing climatic conditions. These in the UK have broadly been identified as warmer, wetter winters, hotter, drier summers and more frequent extreme weather incidents. At the same time they must reduce their climatic impacts. But there are also opportunities.
“We should reward energy conservation rather than simply penalise energy use,” says Hirst. “We expect energy conservation to a be a major win-win for farm businesses that have already suffered large increases in energy costs if government supports effective and practical measures. That is why at the NFU we believe there needs to be a dedicated government minister to co-ordinate climate change review and energy policy, including non-food crops, and bring greater accountability.”
The UK has always had a variable, maritime climate, but there is evidence of greater variation and changes in temperatures and other conditions over recent years that are affecting certain crops. For example, rhubarb has potential problems if it does not receive sufficient cold units early enough in its growing period, and berries and currants also require cold. While in some cases insufficient cold can leave producers without a crop at all, in others it can hinder yield and quality.
Blackcurrant grower Edward Thompson has noticed the effects of climate change in his crop. “We became aware of it following the winter of 1997-98,” says Thompson. “In the spring our plants began displaying symptoms we did not understand.” But it was not until four years later when Thompson visited New Zealand that he understood that an increase in winter temperature was to blame. “Within hours of being in New Zealand and seeing the plants there it became pretty obvious that my plants were showing symptoms caused by lack of winter chill.” As a result, Thompson has changed the practices on his farm considerably. “We have had to introduce new varieties,” he says. “Around 60 per cent of existing varieties do not cope on a commercial scale and we have already seen yields drop dramatically on these. Looking to the future we will be completely dependent on new varieties being bred, with climate change and winter chill requirement as a primary parameter.”
Opportunities that the climate change predicted by the UK Climate Impacts Programme 2002 (UKCIP02) could bring would be a longer season for salad crops and summer vegetables, such as spinach and broccoli, as well as berry fruits, such as strawberries and raspberries. A decline in the number of frosts could make the UK climate suitable for the production of peaches, apricots, walnuts and grapes. And temperature increases will also be beneficial for crops, such as carrots, onions, sweetcorn, peas and beans. All of this could mean less reliance on imports, particularly as other sources will also be dealing with their own climate-change scenarios rendering production difficult.
But, based on UKCIP02, the increase in the number of hot and very hot days could mean damage to some soft fruit and salad crops. It will also create different pest and disease problems such as potato blight.
Any declining levels of summer rainfall will bring an impact that could see crop yields fall and will of course lead to increased irrigation needs. While increases in winter rainfall could cause different pest and disease problems as well as making any late harvesting problematic.
And an increase in extreme weather frequency such as droughts, torrential rain or high winds will bring the possibility of crop damage or total crop loss as well as damage to buildings and structures and potentially unharvestable fields.
UKCIP02 also warns of a rise in sea level which would have huge implications for almost 60 per cent of the UK’s best agricultural land, which lies at five metres or less above sea level, much of it used for the production of fruit and vegetables in the eastern counties.
The issue of CO2 emissions is also a pressing one, as the UK risks missing its 2010 Kyoto targets as it is on a rising trend of emissions. “Horticulture and farming can make a valuable contribution to reversing this trend, putting the government back on track by mitigation and adaptation,” said Hirst.
A major contributor to environmental problems is the burning of aviation fuel. Air freight is therefore likely to come under increasing pressure and domestic production may come into its own. In an extreme scenario there could be a swing back to seasonality in fresh produce as imports may become less acceptable among consumers.
Spain is feeling the effects of climate change to its dear cost. But the frosts in the first three months of this year are just an example of what is set to become far more frequent, warns Professor Millán Millán, executive director of the centre for environmental studies of the Mediterranean, Ceam, in Valencia. “Summer storms in the Mediterranean have been decreasing over the last 20 years and are now at only a third of the levels of 50 years ago,” he says. These storms have been vital to horticulture 60-80km inland as the precipitation they bring accumulates as water in wells. “It may not be much water, but 100 per cent of it is used,” explains Millán.
Part of the reason why the storms have been less numerous is because of the change in land use of the coastal wetlands, which have been built up for tourism. Water therefore does not evaporate, storms form too late in the day and it does not rain, according to Millán. Water vapour stores up over the Mediterranean creating a greenhouse effect and making the sea warmer. This accumulated water vapour has to go somewhere else and can cause strong summer floods in central Europe.
The Mediterranean basin is also getting more torrential rain in the autumn, which can be very destructive for crops, especially when it falls as hail. “This has implications not just for Spain, but southern France, Italy and north Africa,” says Millán. “Basically, the Mediterranean always used to be more regular but it is becoming more chaotic.” This explains the colder temperatures and frosts at the beginning of this year in Spain for example, and means we are also likely to see more extreme weather events more frequently in the Mediterranean basin.
But what of the implications for production? “Growers should get much more accurate weather forecasts,” suggests Millán. “Dry frosts can be fought with the right mechanisms. Up to now, Mediterranean producers have never really had to sharpen their wits against the weather in the same way that Florida citrus growers have. So I think in the future we will see growers getting better protection.”
And of course, Florida has been facing up to hurricanes more recently than the devastation of frosts. According to the National Oceanic & Atmospheric Administration (NOAA) of the US department of commerce, this year’s record-breaking hurricane season is more to do with the fact that the Atlantic Basin is in the active phase of a multi-decadal cycle in which optimal conditions in the ocean and atmosphere, including warmer-than-average sea-surface temperatures and low wind shear, enhance hurricane activity. “Any minor signal of the potential impact of climate change on hurricane activity is grossly dwarfed by the multi-decadal cycle,” a NOAA spokesman says. “It is not just a matter of climate change and warmer water temperatures - that is just one ingredient - there have to be a number of oceanographic and atmospheric parameters.”
So while this hurricane season has shattered records as the first with 26 named storms and the first with 13 hurricanes including three at category five, things look set to continue. “Evidence of this active cycle was demonstrated this year as the Atlantic Basin produced the equivalent of more than two entire hurricane seasons over the course of one,” says David Johnson, director of the NOAA national weather service. “Because we are in an active hurricane era, it’s important to recognise that with a greater number of hurricanes comes increasing odds of one striking land.”
And it is also important to remember that landfall may not just be in the US, but that these storms can also bring devastation to Central America, Mexico and the Caribbean islands, causing problems for a full range of crops but most notably citrus and bananas, mangoes and melons.
“I’d like to foretell that next year will be calmer, but I can’t,” says Conrad Lautenbacher, undersecretary of commerce for oceans and atmosphere and NOAA administrator. “Historical trends say the atmosphere patterns and water temperatures are likely to force another active season upon us.”
The effects of climate change, and the multi-decadal cycle, are therefore here to stay, but there are ways of dealing with them, concludes Millan: “There are mechanisms that can cure diseases if we know when they are coming.”
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