KYOTO AND CANADIAN AGRICULTURE
An Update
By Terry Daynard, OCPA Executive Vice-President
Canada
agreed to reduce net emissions of greenhouse gases (GHG) by six per cent by the
years 2008-2012, relative to 1990 emissions, at an international conference in
Kyoto, Japan in late 1997. The Government of Canada then created a Climate Change
Secretariat (CCS) and a large number of groups or “tables” to discuss strategies
for meeting this target. The tables of direct interest to corn farmers were those
on agriculture, “sinks,” and transportation energy. The tables have now completed
their reports and the CCS and others in the Canadian government are considering
next steps.
The Agricultural Table considered emissions associated with on-farm operations other than those involving fuel
consumption. (This exclusion seems strange in considering a whole-farm approach to emission reduction, but that’s
the federal approach.) An Environment Canada report on estimated Canadian emissions in 1997 – the last year for
which estimates are available – states that Canadian agriculture was responsible for 64 million tonnes of GHG,
or about 9.4 per cent of total Canadian emissions of 682 million tonnes. Note that these are expressed as CO2 equivalents
with a tonne of methane equivalent to 21 tonnes of CO2 in atmospheric warming potential, and a tonne of nitrous
oxide (NO2) being equivalent to 310 tonnes of CO2. An Agriculture and Agri-Food Canada report issued in 1998 estimated
that CO2 emissions caused by direct and indirect (input manufacturing, etc.) energy consumption in agriculture
were about 26 million tonnes in 1996 - and to this should be added an unestimated amount for off-farm transportation
of farm inputs and products. In total, Canadian agriculture probably accounts for about 100 million tonnes of GHG,
or about 14-15 per cent of the Canadian total.
According to the Environment Canada report, of the 64 million tonnes of GHG emissions attributed to agriculture,
about 40 million is as NO2 from soils, 18 million is as methane from animals (almost all from dairy and beef cattle),
4.4 million is as methane from anaerobic manure storage (mainly swine and dairy) and 4.6 million is as nitrous
oxide from manure exposed to air (mainly beef). Of the 40 million tonnes of CO2 equivalents coming as nitrous oxides
from soil, about five million was linked to synthetic fertilizer applications, six million from manure applications
and from droppings by grazing animals, four million from N fixation by legumes, nine million from crop residue
decomposition, and 11 million as ‘indirect’ losses - e.g., losses coming from soil nitrates after they leave farm
fields. As the Agriculture Table notes, however, all of these estimates are very crude, based on inadequate scientific
data. But they do give some indication of relative importances of agricultural sources (fuel usage not included).
The NO2 oxide emission estimates are the least accurate, with the science being poorly developed. For example,
field data from both the University of Guelph and University of Alberta have shown that 90 per cent of annual NO2
emissions can occur within a 24-hour period in early spring, during a period of ground thawing, snow melting and
water-logged soil conditions. Whether these occur from NO2 created at that time, or from NO2 created over a longer
time period and released then, is unknown, though the former is suspected.
There are some data suggesting that significantly greater NO2 losses occur with N application as anhydrous ammonia
than with other sources of fertilizer nitrogen, though these are very preliminary. Also, though Environment Canada
calculations are based solely on total amounts of nitrogen fertilizer and manure applied, the scientific rationale
for this assumption of direct linkages is weak. For example, in the University of Guelph research, a most significant
factor affecting springtime NO2 emissions appeared to be amount of springtime ground cover (insignificant losses
occur with good ground cover). In addition, late autumn concentrations of nitrates in soil might be expected to
be far more closely linked to springtime losses, than the rates of N allocation many months earlier.
The Agricultural Table recommends the need for much more research, especially in the areas of manure management,
ruminant nutrition (can methane emissions be reduced by changing diets?), nitrate losses from soils and soil carbon
sequestration. The table emphasized the importance of carbon sequestration in agricultural soils as a means of
reducing net emissions.
The size of the potential for storing carbon as added soil organic matter in farm soils is uncertain. The Sink
Table estimated the opportunity at 18 million tonnes of CO2 per year. Although some researchers have suggested
that this estimate may be too high, most of those associated with the Canadian GHG and agriculture process agree
that soil carbon sequestration achieved through no tillage, and altered cropping systems, is crucial in Canadian
strategies to limit net agricultural emissions. This is especially so, given projections for substantial increases
in pork and beef production during the next few years, with associated increases in manure, methane emissions and
NO2 production from manure.
The role of soil carbon sequestration may also be critical to the overall ability of Canada to meet its Kyoto obligations,
given that a six per cent reduction relative to 1990 emission levels will mean a 21-26 per cent reduction compared
to projected business-as-usual estimates for 2008-2012.
Internationally, Canada has still not secured acceptance of its position that agricultural soil sequestration should
be included in a final, amended Kyoto agreement. Allies include the U.S., Japan, Australia and several other developed
countries, though the European Union remains opposed, and developing countries are uncertain about their ability
to use this vehicle. (They may lack the infrastructure and scientific expertise to measure the sequestration in
third world farm soils.) This will come to a head at a 2000 meeting of the Council of Parties (which means participating
countries).
A committee of the Ontario Field Crop Research Coalition chaired by Don McCabe, OCPA director for Lambton, and
a subcommittee of researchers chaired by Dr. Bev Kay, Land Resource Science, University of Guelph, has recently
been created. Its mandate is to plan, secure needed funding and implement research in Ontario - and, perhaps, provinces
to the east - on opportunities to increase soil carbon sequestration through expanded use of no tillage and to
understand how to best reduce NO2 emissions from farm soils, while maintaining or improving farm profitability.
Given the number of sites required and difficulties in measuring relatively small amounts of annual CO2 and NO2
emissions from soils which have high inherent levels of carbon and nitrogen, an estimated $1 million or more in
funding will be required for the multi-year program. The hope is that this can be procured through a combination
of federal, provincial and industry sources. The goal is initiation in 2000.
A
final subject is fuel ethanol. Unfortunately, ethanol fell between the cracks
of the mandates of the Agricultural Table and the Transportation Energy Table.
However, both tables did note the potential for renewable fuels to reduce net
CO2 emissions, but the references are not strong. The best source of information
is a recent study by Levelton Engineering for Agriculture and Agri-Food Canada
and Natural Resources Canada which calculated a 39 per cent reduction in net GHG
emissions when a litre of ethanol made at the Commercial Alcohols Inc. plant in
Chatham replaces a litre of gasoline.
Another recent study completed by Levelton for Agriculture and Agri-Food Canada and released in January, suggests
the benefit could be even higher from the use of corn stover for ethanol manufacture. It should be noted, however,
that the corn stover study was based on projected plant operations, versus analysis of an operating plant in the
case of the ethanol-from-corn-grain study.
Kyoto obligations will figure substantially in future OCPA research and market development plans to reduce tillage,
use N fertilizer and encourage the expanded production of fuel ethanol from corn in Ontario.
References:
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