With increased global trade, the spread of so-called invasive pest species has increased greatly over the last few hundred years. While long-distance trade has long been a feature of civilizations and cultures the world over, something that has changed somewhat in recent times has been the cheapness and speed at which it can occur — a situation that is almost entirely due the exploitation of fossil fuel reserves (and before that unsustainable deforestation of very old-growth tree stands).
Previous to this “cheapening” of long-distance trade, the scale involved was much lesser (meant to cater to the whims of the rich), and didn’t generally involve fresh food. With the rise of long-distance shipping of fresh food, though, has come the long-distance shipping of agriculturally dangerous insect pests and plant pathogens.
Related to all of this, in more recent times, is the part that climate weirding and warming has allowed some pests and pathogens to proliferate rapidly in regions where they either previously weren’t present or weren’t able to maintain more than the barest population levels.
Emerald ash borer beetles. Deer ticks. Malaria-carrying mosquitos. Rust fungus. Etcetera.
Such world travelers now essentially represent plagues on the new territories that they have colonized. Perhaps a bit like the effect that relatively rich foreign tourists have on the beaches of some of the poorer parts of the world? Of course, in this case, rather than littering a location with carelessly discarded detritus (“It’s not my country, who cares?”), the world travelers in question are destroying the agricultural and forestry systems on which much human economy depends.
With such a turn of events many places are now facing a situation whereby only a couple of decades time will see populations forced to crash.
An important but often unspoken component in all of this is that as climate change continues intensifying, such pest plagues will become more and more common. Accompanying the spread of these agricultural and forestry industry pests will be numerous dangerous disease vectors — such as various types of mosquitos prone to carrying dangerous viruses and microbes, ticks, and various types of parasitic nematodes and worms.
This situation will be further amplified by the growing loss of biodiversity. To use the situation with ticks as an example: much of the driver of rapid tick population expansion in many regions around the world in recent times has been the loss of large predatory animals and the subsequent boom amongst common tick carriers (deer, etc.). With further loss of biodiversity such unchecked population growth will become more and more common amongst many types of parasites and pests.
Commenting about the more direct effects of climate change, US Department of Agriculture economist Geoffrey Donovan stated (in an interview with Thomson Reuters Foundation): “You are going to have extreme weather events that can spread these pests more readily. … It cannot be a good thing at all.”
Reuters provides more: “Pests already cause losses of around $220 billion a year, or around 10-16% of harvests, the United Nations’ Food and Agriculture Organization (FAO) said at a conference this week. At the same time, trade in agricultural products is vast: it is worth $1.1 trillion annually, the FAO said, of which food accounts for 80%. But unless this process is carefully managed, it brings increased risks of pests and diseases taking hold in new countries, the FAO warned.
“That can happen with the products themselves, but there are risks too with the packaging in which they are shipped: most is made of wood, said Lois Ransom, chair of the Commission on Phytosanitary Measures (CPM), which organized the conference.
“… The USDA economist Donovan urged experts and officials from 140 countries attending the conference to see trees as a public health infrastructure, ‘a fundamental part of human well-being’. In 2013, Donovan conducted a study that found US counties infested with the emerald ash borer beetle had higher levels of human deaths linked to cardiovascular and lower-respiratory diseases.
“And this increases as the infestation progresses…the more trees die, the more people die,” Donovan told the conference. The study in question estimates that over 21,000 people have died in the US (across 15 states) due to the loss of the trees via death by emerald ash borer beetle.
Expect to see more of the same as time goes by and opportunistic pests and parasites expand their territories into regions where effective biological boundaries do not exist (i.e., predatory animals). The effects that this will have on the world’s agricultural systems are likely to be profound, and to spur mass migrations of various kinds.