Repression and displacement, often violent, of remaining rural populations, illness, falling local food production have all featured in this picture.
We currently face a desperate, almost farcical push for GM crops in the UK and Europe, characterised by hyperbolic and inaccurate claims.
So rather than taking those claims on trust, let's look at the impacts of GM crops in countries that have adopted them. That means North and South America, where GM crops were first launched in 1996.
Argentina and Paraguay
The cultivation of herbicide tolerant crops in Argentina began in 1996 with GM soya and spread swiftly through the country. As Argentina's Grupo Reflexion Rural (GRR) wrote to the Vatican in April 2013,
"The model was based on the political decision that Argentina, which had once been the grain basket of the world and a producer of healthy and high-quality foods, would be transformed into a producer of animal forage, firstly, to provide fodder for European livestock, and then for livestock in China."
At first, herbicide tolerant crops seemed to simplify the farming process, especially for larger mechanised farms. Instead of skillful weed management, farmers applied large quantities of the herbicide glyphosate, mainly from the air.
Small farmers driven to the slums
Powerful groups of investors helped drive GM soya production. Small farmers could not compete and many have left or been driven off their land, often into urban slums.
People who remain in the countryside and small towns find themselves bombarded from the air with increasingly complex mixtures of chemicals intended to combat the problem of increasing weed and pest resistance.
Although GM crops were promoted as a means to reduce levels of pesticides used, pesticide use in Argentina has increased massively, "from nine million gallons (34 million litres) in 1990 to more than 84 million gallons (317 million litres) today".
Stillbirths and birth defects
In 2010, following years of mounting harm and protests, the Faculty of Medical Sciences from the National University of Córdoba called a first meeting for doctors working in the crop-sprayed towns in several provinces of Argentina.
"The physicians stressed that they have been serving the same populations, in general, for over 25 years, but what they found in recent years was quite unusual and strictly linked to systemic sprayings of pesticides.
"For example, Dr. Rodolfo Páramo, a paediatrician and neonatologist at the public hospital of Malabrigo, a Northern city in Santa Fe, highlighted the alarm he experienced when he found 12 cases of birth defects in newborns, out of 200 births per year in 2006.
Repression and displacement, often violent, of remaining rural populations, illness, falling local food production have all featured in this picture.
"This situation is analogous with the four cases of stillbirths due to birth defects in the small town of Rosario del Tala, in Entre Ríos, both areas characterised by massive pesticide spraying."
The evidence is building
Since that meeting, reports of illness caused by agrochemicals have continued to accumulate, along with evidence of failure to apply any rules about spraying, or to inform people about the dangers.
Meanwhile GM crops continue to expand in Argentina, covering around 24 million hectares, some two thirds of the total arable land available, according to the International Service for the Acquisition of Agri-Biotech Applications (ISAAA). The figure is indirectly confirmed by figures for soya just planted (7th February 2014) of 20,350,000 ha. Paraguay has suffered similarly devastating impacts, starting a little later than Argentina.
Repression and displacement, often violent, of remaining rural populations, illness, falling local food production have all featured in this picture.
Indigenous communities have been displaced and reduced to living on the capital's rubbish dumps. This is a crime that we can rightly call genocide - the extinguishment of entire Peoples, their culture, their way of life and their environment.
Forest loss in Argentina and Paraguay
Paraguay has lost nearly a million hectares and Argentina nearly two million hectares of forest since 2004 alone, with GM soya considered to be a major driver.
The impacts include biodiversity loss, including many species found nowhere else, and displacement of indigenous peoples, some not previously contacted, plus impacts on soils and water, regional and local climate change and changes in rainfall.
This is shortsighted destruction driven by short-term profits. And it is criminal - ecocide and genocide rolled into one.
Brazil - the world's largest agrochemical user
Brazil, Uruguay and Bolivia have also been affected by the spread of GM soya. A Brazilian agronomist, Leonardo Melgarejo, who represents the Ministry of Agrarian Development at the country's GMO regulatory body, says that GM crops are weakening the social fabric that is essential if people are to be able to flourish in rural areas.
He also notes that Brazil, where GM crops are grown on 36 million hectares, has become the largest user of agrochemicals in the world. [Google translation into English]
It is leading to a vicious cycle of weed resistance requiring the use of ever more, and more toxic, herbicides. To address this, Brazil is now considering the introduction of a GM crop that tolerates 2,4-D (see below).
The US - more of the same
Here, 'RoundUp Ready' crops - resistant to Monsanto's proprietary herbicide based on glyphosate - were rapidly adopted because they provided farmers a "simple, flexible, and forgiving weed management system", as Charles Benbrook reports in 'Impacts of genetically engineered crops on pesticide use in the US - the first sixteen years'.
As a result, herbicide use increased in the US by an estimated 239 million kilograms between 1996-2011, "with HR [herbicide resistant] soybeans accounting for 70% of the total increase across the three HR crops". That is, soya, maize, and oilseed rape/canola. "Rising reliance on glyphosate accounted for most of this increase."
Gradually news of the appearance of several different kinds of weed resistant to glyphosate began to emerge, increasing year on year until now some 20-25 million hectares may be affected.
The response has been to use older and more toxic herbicides such as 2,4-D in tank mixes of agrotoxics and to develop new 'stacked' GM seeds with several traits for resistance to different herbicides.
Proposing 2,4-D resistant crops, 'stacked' crops and more
Generally known as '2,4-D', 2,4-Dichlorophenoxyacetic acid was discovered through research during World War Two to identify biological warfare agents for destroying crops and first marketed in 1944 by Dow Chemical.
It was widely used in Vietnam as a component of the defoliant Agent Orange. Now Dow Agrosciences seeks to release genetically engineered soybean and corn resistant to 2,4-D in Brazil, Argentina and the US.
Dow's proposed crops are stacked with traits for resistance to other herbicides as well, including glufosinate and glyphosate.
Hardly surprising perhaps, considering that there are already weeds in the US that are resistant to 2,4-D.
Increases in herbicide volumes
Monsanto is also producing genetically engineered seed stacked with multiple traits, notably resistance to the herbicides dicamba and glufosinate.
It is estimated that releasing the 2,4-D products could increase the volume of herbicide sprayed, possibly by up to by 50%, and 2,4-D has negative impacts on crops, ecosystems, animals and people.
The same is true of dicamba. Both are also implicated in the growing number of cases of pesticide drift and destruction of other farmers' crops.
Why should Europe want to repeat the experience?
Faced with this accumulating evidence of severe harm, Europe has been wise to resist the pressure to adopt GM crops for cultivation except for a GM maize mainly grown in Spain.
In the face of the evidence from countries with experience of these crops, and their associated cocktails of agrotoxics, why should Europe be forced to consider another GM crop for cultivation?
But Europe should go further. The soya boom is driven by markets for animal feed, in the form of soya meal or cake, and biodiesel from soya oil. Vast quantities of both are imported into Europe, making it a major driver of South America's unfolding GM disaster.
The EU should surely stop importing GM animal feeds and oils from North and South America.
Europe: for a rich and varied GM-free agriculture
Indeed Europe should change its whole approach to livestock and crop production to address human health impacts, biodiversity loss and climate change.
Far from being a "museum of world farming" as the UK's current environment minister, Owen Paterson, likes to claim, Europe could show the way to a rich and varied GM free agriculture that provides nutritious, healthy food and jobs.
It would at the same time address the profound degradation of soils and accelerating biodiversity loss, caused to a great extent by the industrial model of agriculture to which genetically engineered crops belong.
Helena Paul has worked for 25 years on issues including indigenous peoples' rights and tropical forests; oil exploitation in the tropics; biodiversity, including agricultural biodiversity; patents on life and genetic engineering (GE); and corporate power. She helped co-found GM Freeze and Genetic Engineering Network in 1999 and has been chair of the former ever since.
She has co-authored a number of papers on agriculture, climate change and biodiversity, and the book Hungry Corporations: Transnational Biotech Companies Colonise the Food Chain (Helena Paul and Ricarda Steinbrecher, Zed Books 2003).
This article is an extract from an essay written for a book of essays: The Chains of War - nuclear weapons, militarisation and their impact on society, edited by Angie Zelter, to be published by Luath in Spring 2014.