Jonica writes that "there has been a decline in global agricultural production of Maize, Wheat and Rice".
But she is actually referring to a decrease in the GROWTH RATE of output. Cereal output of itself (all three plus several other species like oats or barley) has been growing steadily since 1961, and in fact cereal production in 2014 is an all-time record, overcoming the previous all-time record of 2013, which in turn overcame the previous all-time record of 2011, and so on. Data up to 2013 are all in FAOSTAT, for 2014 preliminary estimates see FAO's Cereal Supply and Demand Brief, http://www.fao.org/worldfoodsituation/csdb/en/.
Now, the growth rate is not equivalent to the potential production growth allowed by technology and natural resources, but to the amount dictated by demand. As incomes grow, demand for staple food (like cereals) tends to stagnate while demand increases for other foods (fruit, vegetables, vegetable oils, meat, dairy products and so on). Per capita output of cereals is in fact stagnant since the 1980s, and food consumption of cereals is actually declining, while overall food consumption improves steadily in terms of calories, protein and micronutrients. Per capita output of those other foods correspondingly increases too. As population growth further decelerates as expected in coming decades, and per capita incomes continue to grow, this process is expected to continue. Even if the proportion of cereals going to other uses, such as animal feed or feedstock for biofuels, have been (slightly) increasing, per capita output of cereals is stalling, due to (slightly) declining per capita human consumption of cereals as food. One may promptly find this out by going to FAOSTAT production section to get the series of cereals (total), and to the population section to get population, copy both to a spreadsheet and do the division. For human food consumption of cereals one has to go to FAOSTAT's Food Balances section, choose Commodity Balances - Crop primary equivalent, and then select "Cereals (excluding beer)" in the Items box (while selecting "World" and the years desired). Per capita cereal output has been oscillating between 320 and 350 kg/year since about 1980 (the higher figure was only achieved in 2013 and 2014, but slightly lower figures were common in the 1980s). Per capita food consumption of cereals has gone from 127 kg/yr in 1961 to 148 in 1986 and 144 in 2011 (latest year available). Calories per capita at world level have grown from 2194 in 1961, to 2568 in 1986 and 2868 in 2011, but calories from cereals are much more stable: 929, 1124, 1115 in the same years. The substitution of other foods for cereals is going on in all regions, including the more poorly fed like Sub Saharan Africa or South Asia. At world level, all the very significant increase in calories since 1990 came from non-cereal foods, and this is also the tendency for all major regions of the globe. So basing the analysis on cereals alone is bound to be misleading.
Jonica also writes: "I really do not see why climate change has beneficial implications for agriculture."
In fact, it does not have to be beneficial, on the whole. Most projections show a global (small) negative effect. But that small negative effect on total agricultural production (which in turn results from rather pessimistic and precautionary assumptions about the future) applies to the output that would be achieved in the future in the absence of climate change, not to the output achieved today. In the absence of climate change, that future output would be much larger than today's, so the small negative effect of climate change would not matter much. Anyway, just to respond to Jonica's implied question: climate change beneficial effects on agriculture arise from several sources; one is the improved agricultural conditions in temperate zones: new lands become cultivable in North America and Eurasia due to a warmer climate, and many lands in temperate regions improve their productivity due to lengthening of growing period, and the like. Secondly, more CO2 in the atmosphere increases photosynthesis (especially for C3 crops like wheat) and reduces water needs for C4 crops (like maize). Thirdly, global warming means also more global rainfall, albeit some regions would get drier (e.g. Northern Mexico or Southern Africa); increased rainfall is in general beneficial for agriculture by increasing the flow of irrigation water and improving conditions for rain-fed cultivation, especially in semiarid zones. The increase in CO2 in recent decades is already having that effect on crops and natural vegetation, as shown by several studies such as the Donohue article I cited in a previous post to this forum.
With the expected growth in population and income, demand for food and hence the required food output by 2050 is estimated to be 50-70% larger than in 2000. These figures imply an annual growth rate between 0.81% and 1.06% per year from 2000 to 2050; food output grew already by 39% in 2000-2013 at an annual 2.56%, so the required growth in the remaining years to 2050 should be just 22.6%, at annual 0.55%.
This expected growth is not all that scary: production is increasing already much faster than required to reach that goal, as it has been doing for more than half a century. The rate of growth of food output has been almost permanently around 2.5% per year in every decade since the sixties. By all accounts it is extremely unlikely that the average growth rate for 2013-50 falls so precipitously as to fall be just 0.55% per year. But even in that unlikely case, and with such minuscule annual growth, the output in 2050 would indeed be 70% greater than in 2000, thus responding to the expected demand from an expected population of about 9.5 billion as per the latest UN projections (on which more below). Notice, furthermore, that projected demand by 2050 includes the excess demand of obese and overweight people, which are expected to increase in numbers and fatness in the intervening years, in both rich and developing countries, under the pessimistic assumption that nothing stops or slows down the wave of over-eating that pervades the world today and is reaching emerging countries very fast.
Even if no further technological innovation occurs in agriculture from here to 2050 (another implausible assumption in the century of biology), the mere process of diffusion of existing technology throughout developing and emerging countries, which is already taking place, would cause an annual increase in production far greater than 0.55% per year.
Jonica also writes that "it is predicted that we will be 10 billion by 2050".
Not quite. The latest UN figure (medium variant) for 2050 is 9.55 billion, a bit above previous projections of 9.2-9.3 bn. This slight increase is in turn only due to an apparently innocuous change in assumptions introduced in recent UN updates: up to 2010 it was assumed that fertility rates would converge to a common value of 1.85 children per woman; since 2010 it was suddenly assumed that they would converge to replacement level (2.1 children), thus increasing the projection for 2050 (and even more for 2100). There is no sign of such convergence of all countries (at different pace) to a common value; changes in fertility are a function of income and education, but the UN demographers did not take those factors into account, nor the fact that incomes and education are rising fast throughout the developing growth, and are expected to keep rising, thus putting the brakes on fertility. A regression model over all countries, with those variables set at the values observed in recent decades, and then projected to the future with the expected growth in per capita incomes adopted for the IPCC climate change projections, would predict continuing low (and decreasing) fertility at world level. I won't bet the farm on mothers in China or Brazil starting to bear more children any soon.
Improving the lot of the poor, so they can afford their daily bread (and also their daily cheese, chicken, peaches, and all other foods they may care about, plus all other necessaries of life) is the main priority and challenge, not the production of food which is already more than enough for everybody, and is expected to keep being so in the foreseeable future.
@Jonica Otarra 's comment of 6 April.
Jonica writes that "there has been a decline in global agricultural production of Maize, Wheat and Rice".
But she is actually referring to a decrease in the GROWTH RATE of output. Cereal output of itself (all three plus several other species like oats or barley) has been growing steadily since 1961, and in fact cereal production in 2014 is an all-time record, overcoming the previous all-time record of 2013, which in turn overcame the previous all-time record of 2011, and so on. Data up to 2013 are all in FAOSTAT, for 2014 preliminary estimates see FAO's Cereal Supply and Demand Brief, http://www.fao.org/worldfoodsituation/csdb/en/.
Now, the growth rate is not equivalent to the potential production growth allowed by technology and natural resources, but to the amount dictated by demand. As incomes grow, demand for staple food (like cereals) tends to stagnate while demand increases for other foods (fruit, vegetables, vegetable oils, meat, dairy products and so on). Per capita output of cereals is in fact stagnant since the 1980s, and food consumption of cereals is actually declining, while overall food consumption improves steadily in terms of calories, protein and micronutrients. Per capita output of those other foods correspondingly increases too. As population growth further decelerates as expected in coming decades, and per capita incomes continue to grow, this process is expected to continue. Even if the proportion of cereals going to other uses, such as animal feed or feedstock for biofuels, have been (slightly) increasing, per capita output of cereals is stalling, due to (slightly) declining per capita human consumption of cereals as food. One may promptly find this out by going to FAOSTAT production section to get the series of cereals (total), and to the population section to get population, copy both to a spreadsheet and do the division. For human food consumption of cereals one has to go to FAOSTAT's Food Balances section, choose Commodity Balances - Crop primary equivalent, and then select "Cereals (excluding beer)" in the Items box (while selecting "World" and the years desired). Per capita cereal output has been oscillating between 320 and 350 kg/year since about 1980 (the higher figure was only achieved in 2013 and 2014, but slightly lower figures were common in the 1980s). Per capita food consumption of cereals has gone from 127 kg/yr in 1961 to 148 in 1986 and 144 in 2011 (latest year available). Calories per capita at world level have grown from 2194 in 1961, to 2568 in 1986 and 2868 in 2011, but calories from cereals are much more stable: 929, 1124, 1115 in the same years. The substitution of other foods for cereals is going on in all regions, including the more poorly fed like Sub Saharan Africa or South Asia. At world level, all the very significant increase in calories since 1990 came from non-cereal foods, and this is also the tendency for all major regions of the globe. So basing the analysis on cereals alone is bound to be misleading.
Jonica also writes: "I really do not see why climate change has beneficial implications for agriculture."
In fact, it does not have to be beneficial, on the whole. Most projections show a global (small) negative effect. But that small negative effect on total agricultural production (which in turn results from rather pessimistic and precautionary assumptions about the future) applies to the output that would be achieved in the future in the absence of climate change, not to the output achieved today. In the absence of climate change, that future output would be much larger than today's, so the small negative effect of climate change would not matter much. Anyway, just to respond to Jonica's implied question: climate change beneficial effects on agriculture arise from several sources; one is the improved agricultural conditions in temperate zones: new lands become cultivable in North America and Eurasia due to a warmer climate, and many lands in temperate regions improve their productivity due to lengthening of growing period, and the like. Secondly, more CO2 in the atmosphere increases photosynthesis (especially for C3 crops like wheat) and reduces water needs for C4 crops (like maize). Thirdly, global warming means also more global rainfall, albeit some regions would get drier (e.g. Northern Mexico or Southern Africa); increased rainfall is in general beneficial for agriculture by increasing the flow of irrigation water and improving conditions for rain-fed cultivation, especially in semiarid zones. The increase in CO2 in recent decades is already having that effect on crops and natural vegetation, as shown by several studies such as the Donohue article I cited in a previous post to this forum.
With the expected growth in population and income, demand for food and hence the required food output by 2050 is estimated to be 50-70% larger than in 2000. These figures imply an annual growth rate between 0.81% and 1.06% per year from 2000 to 2050; food output grew already by 39% in 2000-2013 at an annual 2.56%, so the required growth in the remaining years to 2050 should be just 22.6%, at annual 0.55%.
This expected growth is not all that scary: production is increasing already much faster than required to reach that goal, as it has been doing for more than half a century. The rate of growth of food output has been almost permanently around 2.5% per year in every decade since the sixties. By all accounts it is extremely unlikely that the average growth rate for 2013-50 falls so precipitously as to fall be just 0.55% per year. But even in that unlikely case, and with such minuscule annual growth, the output in 2050 would indeed be 70% greater than in 2000, thus responding to the expected demand from an expected population of about 9.5 billion as per the latest UN projections (on which more below). Notice, furthermore, that projected demand by 2050 includes the excess demand of obese and overweight people, which are expected to increase in numbers and fatness in the intervening years, in both rich and developing countries, under the pessimistic assumption that nothing stops or slows down the wave of over-eating that pervades the world today and is reaching emerging countries very fast.
Even if no further technological innovation occurs in agriculture from here to 2050 (another implausible assumption in the century of biology), the mere process of diffusion of existing technology throughout developing and emerging countries, which is already taking place, would cause an annual increase in production far greater than 0.55% per year.
Jonica also writes that "it is predicted that we will be 10 billion by 2050".
Not quite. The latest UN figure (medium variant) for 2050 is 9.55 billion, a bit above previous projections of 9.2-9.3 bn. This slight increase is in turn only due to an apparently innocuous change in assumptions introduced in recent UN updates: up to 2010 it was assumed that fertility rates would converge to a common value of 1.85 children per woman; since 2010 it was suddenly assumed that they would converge to replacement level (2.1 children), thus increasing the projection for 2050 (and even more for 2100). There is no sign of such convergence of all countries (at different pace) to a common value; changes in fertility are a function of income and education, but the UN demographers did not take those factors into account, nor the fact that incomes and education are rising fast throughout the developing growth, and are expected to keep rising, thus putting the brakes on fertility. A regression model over all countries, with those variables set at the values observed in recent decades, and then projected to the future with the expected growth in per capita incomes adopted for the IPCC climate change projections, would predict continuing low (and decreasing) fertility at world level. I won't bet the farm on mothers in China or Brazil starting to bear more children any soon.
Improving the lot of the poor, so they can afford their daily bread (and also their daily cheese, chicken, peaches, and all other foods they may care about, plus all other necessaries of life) is the main priority and challenge, not the production of food which is already more than enough for everybody, and is expected to keep being so in the foreseeable future.