Productive land for food production, bioenergy, or preservation of nature is a
limited resource. Climate change mitigation puts additional pressure on land
via higher demand for bioenergy to replace fossil fuels and via restrictions on
deforestation—two processes that limit the availability of land for food production,
and may thus also raise food prices. Methane and nitrous oxide emissions
from agriculture may also need to be reduced to efficiently mitigate climate
change. This thesis deals with this in three ways.
In papers I–II, we estimate greenhouse gas emissions from food production
for current diets and expected future developments, together with alternative dietary
developments and potential technical improvements in the agricultural sector.
Costs and possibilities for reaching climate goals are analyzed for the different
diets. The results indicate that a phase out of ruminant products would cut
mitigation cost in half, for staying below a 2?C limit, and it may be necessary if
the climate sensitivity is high.
In papers III–IV, a conceptual and transparent partial equilibrium model of
global land-use competition is developed, analyzed and applied. The model is
to a large degree analytically explored and price differentials between crops are
derived. The model is subjected to a detailed characterization of its mechanisms
and parameters that are critical to the results. We conclude that the total amount
of productive agricultural area and bioenergy yields are of crucial importance to
the price impacts from large-scale introduction of bioenergy. We also show how
limiting bioenergy production to marginal land could be difficult to implement in
practice.
In paper V, we use two established indicators for poverty and sensitivity to
food-price changes to capture peoples’ vulnerability to rising food-prices in four
Sub-Sahara African countries/regions. In contrast to previous studies, we include
all food products instead of just one or a few main staples. We found that the vast
majority of people are net consumers of food and that the inclusion of more than
main staples increases their net position as consumers and thus vulnerability to
high food prices.