Key Messages

Environmental Impacts

1. The relatively intensive and highly productive types of agriculture practiced extensively in NAE have had undesirable impacts on the environment in NAE. How­ever, there is considerable potential for reduction, or in some cases reversal, of these impacts by appli­cation of knowledge to identify and select improved practices. Increased fertilizer use has resulted in raised levels in nitrogen and phosphorus in rivers and coastal wa­ters causing changes in aquatic populations and contribut­ing to eutrophication. Pesticide and sediment runoff from erosion can also damage aquatic populations. Adoption of farming practices to prevent overfertilization has helped to reduce environmental damage (e.g., controlled timing of treatments, more precise rates, creation of buffer zones). Reduction in pesticide use through methods such as inte­grated pest management and switching to less persistent and harmful products has reduced impacts but problems from non-target effects of pesticides remain. Soil quality in parts of NAE has been degraded by a variety of intensive land use and irrigation practices.

2. The adoption of mechanization in NAE has contrib­uted to substantially larger fields and farm units. In some regions, this has resulted in loss of traditional landscapes and hedgerows with a subsequent loss of wildlife habitat and biodiversity. Policies and programs, especially financial payments, are available in some areas of NAE, to restore farmland habitats and increase wildlife populations.

3. Greater intensity of animal production systems, combined with the increased spatial segregation of crop and animal production units, has led to concerns over water and air pollution, development of antibiotic resistance and animal welfare. These changes in produc­tion systems have created areas where the amount of wastes cannot easily be returned as soil amendments, leading to water pollution in many parts of the NAE. Concerns over impacts have led to stronger regulatory frameworks, espe­cially in the EU.

4. Aquaculture production in NAE, especially salmon, has been growing rapidly over the last few decades. Feeding these farmed fish with fishmeal has put fur­ther pressure on fish stocks. Also waste from such operations may overload the capacity of local waters to absorb or process these nutrients, leading to envi­ronmental degradation. Further, caged aquatic livestock can incubate diseases that may infect wild populations and escaped fish bred for fast growth in aquaculture may out-compete native wild populations.

5. Agriculture is a sizable contributor to greenhouse gas emissions, especially of methane and nitrous ox­ide. Greenhouse gas emissions from agriculture are in the range of 7-20% of total country emission inventories (by

radiative effect) for NAE. Approximately 30% of global methane is thought to originate from agriculture, of which digestive fermentation from ruminant livestock is by far the greatest contributor. Agriculture in NAE contributes at least one third of global emissions of nitrous oxide and it is the primary contributor to increases in reactive nitrogen.

6. The evidence for the presence of direct environ­mental impacts arising from the current genetically engineered (GE) crops grown on a large scale com­pared with conventional agriculture remains contro­versial. Conclusions that the production of GE crops in North America have not led to adverse environmental effects are not accepted by some stakeholders. It must be pointed out that the agricultural system chosen as com­parator is important in the evaluation of GE crops. Measur­able reductions of insecticide use have been observed with insect resistant GE crops but not eliminated and vary with crop type. Herbicide tolerant GE crops have facilitated con­servation tillage resulting in environmental benefits. Weed populations tolerant to herbicides used in conjunction with certain GE herbicide tolerant crops have become an issue in some parts of North America, but options exist for their management.

7. Bioenergy crops. The use of crops for the produc­tion of biomass and liquid biofuels is increasing rap­idly. Their use is already having an impact on food crop surpluses, crop production patterns and prices. There is concern that high levels of production of biofuels from food crops could encourage crop production on lands presently reserved for conservation purposes with undesirable effects on the environment.

8.   Reorganization   of   supermarket   supply   chains and consumer demand in NAE for varied fresh food products and counter-seasonal food products have caused an increase in the long-distance transport of food (food miles). Agricultural policies have encouraged the production of high-value horticultural crops in develop­ing countries which must be shipped in high-energy cool chains. While this trend has had negative effects on the en­vironment, primarily because of increased energy use, it has given some farmers in developing countries access to export markets. In contrast, another trend towards sourcing local food whenever possible may reduce food transport miles in the future.

Economic impacts

9. The application of AKST in a dynamic economic and political environment has allowed consumers to purchase food at relatively low prices, but the tech­nologies that have developed from AKST have en­couraged concentration at all levels of the agriculture and food sectors. Declines in prices have forced farmers to adopt more productive practices or increase production and landholdings, reducing the number of farmers and, in many cases, necessitating dependence on off-farm incomes to maintain living standards.