Comments on the first order draft were few:
C: This subsection could give more emphasis to the value of carrying out a multi-sector, consistent integrated assessment, beyond the single impact assessment.
R: Added: Ignoring these effects would lead to biased estimates of the impacts of climate change.
C: I suggest to add the following sentence: "Partial equilibrium models can be more detailed and realistic."
R: Sentence added.
C: The term 'of income' should be omitted. The results are in terms of welfare changes (percentages).
R: Income changed to welfare.
C: The author team should consider characterizing its degree of certainty in these conclusions through use of calibrated uncertainty language per the guidelines for authors.
R: Reject: These are qualitative findings; no uncertainty assessment has been published.
C: This section is highly relevant. In the conclusions possible lines of additional research in this area could be mentioned.
R: This is already done in Section 10.10
C: For this example, it would be helpful to specify the relevant climate/socio-economic scenario employed in the analysis.
R: Assessment was drafted as an example of robust findings across scenarios, and details of specific scenarios are not relevant.
C: The article of Barrios et al. (2010) on rainfall and growth could be considered. Barrios Salvador, Bertinelli Luisito and Eric Strobl, (2010), "Trends in Rainfall and Economic Growth in Africa: A Neglected Cause of the African Growth Tragedy", Review of Economics and Statistics 92(2):350-366, 2010
R: Reference added
10.9. Impacts on markets and development
Prior sections of this chapter present the direct impacts of climate change on the economy sector by sector. There are, however, also indirect impacts. The effects that impacts in one sector may have on the rest of the economy are initially presented, followed by the impacts on economic growth and development.
10.9.1. General equilibrium effects
General equilibrium analysis describes how climate change impacts in one sector propagate to the rest of the economy, how impacts in one country influence other countries, and how macroeconomic conditions affect each impact (Ginsburgh and Keyzer, 1997). There are three channels through which impact diffuse. First, outputs of one sector are used as inputs to other sectors. For example, a change in crop yields would affect the food-processing industry. Second, products compete for the consumers’ finite budget. If, for example, food becomes more expensive, less money would be spent on other goods and services. Third, sectors compete for the primary factors of production (labor, capital, land, water). If more labor is needed in agriculture to offset a drop in crop yields, less labor is available to produce other goods and services. Firms and households react to changes in relative prices, domestically and internationally. Ignoring these effects would lead to biased estimates of the impacts of climate change.
General equilibrium models can provide a comprehensive and internally consistent analysis of the medium-term impact of climate change on economic activity and welfare. However, these models necessarily make a number of simplifying assumptions, particularly with regard to the rationality of consumers and producers and the absence of market imperfections. Partial equilibrium models can be more detailed and more realistic.
Computable general equilibrium models have long been used to study the wider economic implications of changes in crop yields (Kane et al., 1992). (Yates and Strzepek, 1998) show for instance that the impact of a reduced flow of the Nile on the economy of Egypt is much more severe without international trade than with, because trade would allow Egypt to focus on water-extensive production for export and import its food.
Older studies focused on the impact of climate change on patterns of specialization and trade, food prices, food security and welfare (Darwin and Kennedy, 2000; Darwin, 2004; Kane et al., 1992; Reilly et al., 1994; Winters et al., 1998; Yates and Strzepek, 1998). This has been extended to land use (Lee, 2009; Ronneberger et al., 2009), water use (Calzadilla et al., 2011; Kane et al., 1992), and multiple stresses (Reilly et al., 2007). General equilibrium models have also been used to estimate the value of improved weather forecasts (Arndt and Bacou, 2000), a form of adaptation to climate change. Computable general equilibrium analysis has also been used to study selected impacts other than agriculture, notably sea level rise (Bosello et al., 2007; Darwin and Tol, 2001), tourism (Berrittella et al., 2006; Bigano et al., 2008), human health (Bosello et al., 2006) and energy (see 10.2).
(Bigano et al., 2008) study the joint impacts on tourism and coasts, finding that tourism dominates the welfare impacts. (Kemfert, 2002) and (Eboli et al., 2010) estimate the joint effect on the world economy of a range of climate change impacts, but conflate general equilibrium and growth effects. (Aaheim et al., 2010) analyze the economic effects of impacts of climate change on agriculture, forestry, fishery, energy demand, hydropower production, and tourism on the Iberian peninsula. They find positive impacts on output in some sectors (agriculture, electricity) negative impacts in other sectors (forestry, transport) and negligible ones in others (manufacturing, services). (Ciscar et al., 2011) study the combined impact on agriculture, coasts, river floods and tourism in the current European economy. They find an average welfare loss of 0.2-1.0% of welfare but there are large regional differences with losses in Southern Europe and gains in Northern Europe.
The following initial conclusions emerge. First, markets matter. Impacts are transmitted across locations—with local, regional and global impacts-- and across multiple sectors of the economy. For instance, landlocked countries are affected by sea level rise because their agricultural land increases in value as other countries face erosion and floods. Second, consumers and producers are often affected differently. The price increases induced by a reduction in production may leave producers better off while hurting consumers. Third, the distribution of the direct impacts can be very different than the distribution of the indirect effects. For instance, a loss of production may be advantageous to an individual company or country if the competition loses more. Fourth, a loss of productivity or productive assets in one sector leads to further losses in the rest of the economy. Fifth, markets offer options for adaptation, particularly possibilities for substitution. This changes the size, and sometimes the sign of the impact estimate.
10.9.2. Growth effects
10.9.2.1. The rate of economic growth
Climate change would also affect economic growth and development, but our understanding is limited. (Fankhauser and Tol, 2005) investigate four standard models of economic growth and three transmission mechanisms: economic production, capital depreciation, and the labor force. They find that, in three models, the fall in economic output is slightly larger than the direct impact on markets while the 4th model (which emphasizes human capital accumulation) points to indirect impacts that are 1.5 times as large as the direct impacts. The difference can be understood as follows. In the three models, the impacts of climate change crowd out consumption and investment in physical capital, while in the fourth model investment in human capital too is crowded out; lower investment implies slower growth. (Hallegatte, 2005) reaches a similar conclusion. (Hallegatte and Thery, 2007; Hallegatte and Ghil, 2008; Hallegatte and Dumas, 2009) highlight that the impact of climate change through natural hazards on economic growth can be amplified by market imperfections and the business cycle. (Eboli et al., 2010) use a multi-sector, multi-region growth model. The impact of climate change would lead to a 0.3% reduction of GDP in 2050. Regional impacts are more pronounced, ranging from -1.0% in developing countries to +0.4% in Australia and Canada. Sectoral results are varied too, with output changes ranging from output of +0.5% for power generation (to meet increased demand to air conditioning) to -0.7% for natural gas (as demand for space heating falls) and rice.
Using a biophysical model of the human body’s ability to do work, (Kjellstrom et al., 2009) find that by the end of the century climate change may reduce labor productivity by 11-27% in the humid (sub)tropics. Assuming a output elasticity of labor of 0.8, this would reduce economic output in the affected sectors (involving heavy manual labor without air conditioning) by 8-22%. Although structural change in the economy may well reduce the dependence on manual labor and air conditioning would be an effective adaptation, even the ameliorated impact would have a substantial, but as yet unquantified, impact on economic growth.
There are also statistical analyses of the relationship between climate and economic growth. (Barrios et al., 2010) find that the decline in rainfall in the 20th century partly explains the economies of Sub-Saharan Africa have grown more slowly than those of other developing regions. (Brown et al., 2011) corroborate this. (Dell et al., 2012) find that, in the second half of the 20th century, anomalously hot weather slowed down economic growth in poor countries, in both the agricultural and the industrial sectors. (Dell et al., 2009) find that one degree of warming would reduce income by 1.2% in the short run, and by 0.5% in the long run. The difference is due to adaptation. (Horowitz, 2009) finds a much larger effect: a 3.8% drop in income in the long run for one degree of warming.
10.9.2.2. Poverty traps
Poverty is concentrated in the tropics and subtropics. This has led some analysts to the conclusion that a tropical climate is one of the causes of poverty. (Gallup et al., 1999) emphasize the link between climate, disease, and poverty while (Masters and McMillan, 2001) focus on climate, agricultural pests, and poverty. Other studies (Acemoglu et al., 2001; Acemoglu et al., 2002; Easterly and Levine, 2003) argue that climatic influence on development disappears if differences in human institutions (the rule of law, education, etc) are accounted for. However, (Van der Vliert, 2008) demonstrates that climate affects human culture and thus institutions, but this has yet to be explored in the economic growth literature. (Brown et al., 2011) find that weather affects economic growth in Sub-Saharan Africa – particularly, drought decelerates growth. (Jones and Olken, 2010) find that exports from poor countries fall during hot years. (Bloom et al., 2003) find limited support for an impact of climate (rather than weather) on past growth in a single-equilibrium model, but strong support in a multiple-equilibrium model: Hot and wet conditions and large variability in rainfall reduce long-term growth in poor countries (but not in hot ones) and increase the probability of being poor.
(Galor and Weil, 1996) speculate about the existence of a climate-health-poverty trap. (Bonds et al., 2010; Bretschger and Valente, 2011; Strulik, 2008) posit theoretical models and offer limited empirical support, while (Tang et al., 2009) offers more rigorous empirical evidence. This is further supported by yet-to-be-published analyses (Bretscher and Valente, 2010; Gollin and Zimmermann, 2008; Gollin and Zimmermann, 2010; Ikefuji et al., 2010). Climate-related diseases such as malaria and diarrhea impair children’s cognitive and physical development. This leads to poverty in their later life so that there are limited means to protect their own children against these diseases. Furthermore, high infant mortality may induce parents to have many children so that the investment in education is spread thin. An increase in infant and child mortality and morbidity due to climate change would thus trap more people in poverty.
(Ikefuji and Horii, 2012; Zimmerman and Carter, 2003) build a model in which the risk of natural disasters causes a poverty trap: At higher risk levels, households prefer assets with a safe but low return. (Carter et al., 2007) find empirical support for this model at the household level, but (van den Berg, 2010) concludes the natural disaster itself has no discernible impact on investment choices. At the macro-economic level, natural disasters disproportionally affect the growth rate of poor countries (Noy, 2009).
(Devitt and Tol, 2012) construct a model with conflict-poverty trap, and show that climate change may exacerbate this. (Bougheas et al., 1999; Bougheas et al., 2000) show that more expensive infrastructure, for example because of frequent repairs after natural disasters, slows down economic growth and that there is a threshold infrastructure cost above which trade and specialization do not occur, suggesting another mechanism through which climate could cause a poverty trap. The implications of climate change have yet to be assessed.
In sum, the literature on the impact of climate and climate change on economic growth and development has yet to reach firm conclusions. There is agreement that climate change would slow economic growth, by a little according to some studies and by a lot according to other studies. There is disagreement whether climate change would affect the nature of economic development, with some studies suggesting that more people may be trapped in poverty and fewer people enjoying exponential growth.
Aaheim, A., T. Dokken, S. Hochrainer, A. Hof, E. Jochem, R. Mechler, and D.P. van Vuuren, 2010: National responsibilities for adaptation strategies: lessons from four modelling framework. In: Making Climate Change Work for Us: European Perspectives on Adaptation and Mitigation Strategies. [Hulme, M. and H. Neufeldt(eds.)]. Cambridge University Press, Cambridge, pp. 87-112.
Acemoglu, D., S. Johnson, and J.A. Robinson, 2001: The Colonial Origins of Comparative Development: An Empirical Investigation. American Economic Review, 91(4), 1369-1401.
Acemoglu, D., S. Johnson, and J.A. Robinson, 2002: Reversal of fortune: Geography and institutions in the making of the modern world income distribution. Quarterly Journal of Economics, 117(4), 1231-1294.
Arndt, C. and M. Bacou, 2000: Economy-wide effects of climate variability and climate prediction in Mozambique. American Journal of Agricultural Economics, 82(3), 750-754.
Barrios, S., L. Bertinelli, and E. Strobl, 2010: Trends in rainfall and economic growth in Africa: A neglected cause of the african growth tragedy. Review of Economics and Statistics, 92(2), 350-366.
Berrittella, M., A. Bigano, R. Roson, and R.S.J. Tol, 2006: A general equilibrium analysis of climate change impacts on tourism. Tourism Management, 27(5), 913-924.
Bigano, A., F. Bosello, R. Roson, and R.S.J. Tol, 2008: Economy-wide impacts of climate change: A joint analysis for sea level rise and tourism. Mitigation and Adaptation Strategies for Global Change, 13(8), 765-791.
Bloom, D.E., D. Canning, and J. Sevilla, 2003: Geography and poverty traps. Journal of Economic Growth, 8(4), 355-378.
Bonds, M.H., D.C. Keenan, P. Rohani, and J.D. Sachs, 2010: Poverty trap formed by the ecology of infectious diseases. Proceedings of the Royal Society B: Biological Sciences, 277(1685), 1185-1192.
Bosello, F., R. Roson, and R.S.J. Tol, 2006: Economy-wide estimates of the implications of climate change: Human health. Ecological Economics, 58(3), 579-591.
Bosello, F., R. Roson, and R.S.J. Tol, 2007: Economy-wide estimates of the implications of climate change: Sea level rise. Environmental and Resource Economics, 37(3), 549-571.
Bougheas, S., P.O. Demetriades, and T.P. Mamuneas, 2000: Infrastructure, specialization, and economic growth. Canadian Journal of Economics, 33(2), 506-522.
Bougheas, S., P.O. Demetriades, and E.L.W. Morgenroth, 1999: Infrastructure, transport costs and trade. Journal of International Economics, 47(1), 169-189.
Bretscher, L. and S. Valente, 2010: Uneven Development due to Climate Change -- Growth Effects of Climate Change Exposure and Adaptation. In: [Anonymous . Centre of Economic Research, ETH, Zurich.
Bretschger, L. and S. Valente, 2011: Climate change and uneven development. Scandinavian Journal of Economics, 113(4), 825-845.
Brown, C., R. Meeks, K. Hunu, and W. Yu, 2011: Hydroclimate risk to economic growth in sub-Saharan Africa. Climatic Change, 106(4), 621-647.
Calzadilla, A., K. Rehdanz, and R.S.J. Tol, 2011: Trade Liberalization and Climate Change: A CGE Analysis of the Impacts on Global Agriculture. Water, 3(2), 526-550.
Carter, M.R., P.D. Little, T. Mogues, and W. Negatu, 2007: Poverty Traps and Natural Disasters in Ethiopia and Honduras. World Development, 35(5), 835-856.
Ciscar, J.-., A. Iglesias, L. Feyen, L. Szabó, D. Van Regemorter, B. Amelung, R. Nicholls, P. Watkiss, O.B. Christensen, R. Dankers, L. Garrote, C.M. Goodess, A. Hunt, A. Moreno, J. Richards, and A. Soria, 2011: Physical and economic consequences of climate change in Europe. Proceedings of the National Academy of Sciences of the United States of America, 108(7), 2678-2683.
Darwin, R.F., 2004: Effects of Greenhouse Gas Emissions on World Agriculture, Food Consumption, and Economic Welfare. Climatic Change, 66(1-2), 191-238.
Darwin, R.F. and D. Kennedy, 2000: Economic effects of CO2 fertilization of crops: transforming changes in yield into changes in supply. Environmental Modeling and Assessment, 5, 157-168.
Darwin, R.F. and R.S.J. Tol, 2001: Estimates of the Economic Effects of Sea Level Rise. Environmental and Resource Economics, 19(2), 113-129.
Dell, M., B.F. Jones, and B.A. Olken, 2009: Temperature and income: Reconciling new cross-sectional and panel estimates. American Economic Review, 99(2), 198-204.
Dell, M., B.F. Jones, and B.A. Olken, 2012: Temperature Shocks and Economic Growth: Evidence from the Last Half Century. American Economic Journal: Macroeconomics, 4(3), 66-95.
Devitt, C. and R.S.J. Tol, 2012: Civil war, climate change, and development: A scenario study for sub-saharan Africa. Journal of Peace Research, 49(1), 129-145.
Easterly, W. and R. Levine, 2003: Tropics, germs, and crops: how endowments influence economic development. Journal of Monetary Economics, 50(1), 3-39.
Eboli, F., R. Parrado, and R. Roson, 2010: Climate-change feedback on economic growth: Explorations with a dynamic general equilibrium model. Environment and Development Economics, 15(5), 515-533.
Fankhauser, S. and R.S.J. Tol, 2005: On climate change and economic growth. Resource and Energy Economics, 27(1), 1-17.
Gallup, J.L., J.D. Sachs, and A.D. Mellinger, 1999: Geography and Economic Development. International Regional Science Review, 22(2), 179-232.
Galor, O. and D.N. Weil, 1996: The Gender Gap, Fertility, and Growth. American Economic Review, 86(3), 374-387.
Ginsburgh, V. and M.A. Keyzer, 1997: The Structure of Applied General Equilibrium Models. The MIT Press, Cambridge, pp. 555.
Gollin, D. and C. Zimmermann, 2008: Malaria: Disease Impacts and Long-Run Income Differences. In: [Anonymous . Economics Department, Williams College, Williamstown.
Gollin, D. and C. Zimmermann, 2010: Global Climate Change and the Resurgence of Tropical Disease: An Economic Approach. In: [Anonymous . Economics Department, Williams College, Williamstown.
Hallegatte, S., 2005: The long time scales of the climate-economy feedback and the climatic cost of growth. Environmental Modeling and Assessment, 10(4), 277-289.
Hallegatte, S. and P. Dumas, 2009: Can natural disasters have positive consequences? Investigating the role of embodied technical change. Ecological Economics, 68(3), 777-786.
Hallegatte, S. and M. Ghil, 2008: Natural disasters impacting a macroeconomic model with endogenous dynamics. Ecological Economics, 68(1-2), 582-592.
Hallegatte, S. and D. Thery, 2007: Are the economic impacts of climate change underestimated? Revue d'Economie Politique, 117(4), 507-522.
Horowitz, J.K., 2009: The income-temperature relationship in a cross-section of countries and its implications for predicting the effects of global warming. Environmental and Resource Economics, 44(4), 475-493.
Ikefuji, M. and R. Horii, 2012: Natural disasters in a two-sector model of endogenous growth. Journal of Public Economics, 96(9-10), 784-796.
Ikefuji, M., J. Magnus, and H. Sakamoto, 2010: Climate Change, Economic Growth, and Health. In: [Anonymous . Osaka, Institute of Social and Economic Research, Osaka University.
Jones, B.F. and B.A. Olken, 2010: Climate shocks and exports. American Economic Review, 100(2), 454-459.
Kane, S., J.M. Reilly, and J. Tobey, 1992: An Empirical Study of the Economic Effects of Climate Change on World Agriculture. Climatic Change, 21(1), 17-35.
Kemfert, C., 2002: An Integrated Assessment Model of Economy-Energy-Climate – The Model Wiagem. Integrated Assessment, 3(4), 281-298.
Kjellstrom, T., R.S. Kovats, S.J. Lloyd, T. Holt, and R.S.J. Tol, 2009: The direct impact of climate change on regional labor productivity. Archives of Environmental and Occupational Health, 64(4), 217-227.
Lee, H.-., 2009: The impact of climate change on global food supply and demand, food prices, and land use. Paddy and Water Environment, 7(4), 321-331.
Masters, W.A. and M.S. McMillan, 2001: Climate and Scale in Economic Growth. Journal of Economic Growth, 6(3), 167-186.
Noy, I., 2009: The macroeconomic consequences of disasters. Journal of Development Economics, 88(2), 221-231.
Reilly, J.M., N. Hohmann, and S. Kane, 1994: Climate Change and Agricultural Trade: Who Benefits, Who Loses? Global Environmental Change, 4(1), 24-36.
Reilly, J.M., S. Paltsev, B. Felzer, X. Wang, D.W. Kicklighter, J.M. Melillo, R.G. Prinn, M. Sarofim, A.P. Sokolov, and C. Wang, 2007: Global Economic Effects of Changes in Crops, Pasture, and Forests due to Changing Climate, Carbon Dioxide, and Ozone. Energy Policy, 35, 5370-5383.
Ronneberger, K., M. Berrittella, F. Bosello, and R.S.J. Tol, 2009: KLUM@GTAP: Introducing biophysical aspects of land-use decisions into a computable general equilibrium model a coupling experiment. Environmental Modeling and Assessment, 14(2), 149-168.
Strulik, H., 2008: Geography, health, and the pace of demo-economic development. Journal of Development Economics, 86(1), 61-75.
Tang, K.K., D. Petrie, and D.S.P. Rao, 2009: The income-climate trap of health development: A comparative analysis of African and Non-African countries. Social Science and Medicine, 69(7), 1099-1106.
van den Berg, M., 2010: Household income strategies and natural disasters: Dynamic livelihoods in rural Nicaragua. Ecological Economics, 69(3), 592-602.
Van der Vliert, E., 2008: Climate, Affluence, and Culture Cambridge University Press, Cambridge, pp. 264.
Winters, P., R. Murgai, E. Sadoulet, A. De Janvry, and G. Frisvold, 1998: Economic and welfare impacts of climate change on developing countries. Environmental and Resource Economics, 12(1), 1-24.
Yates, D.N. and K.M. Strzepek, 1998: An assessment of integrated climate change impacts on the agricultural economy of Egypt. Climatic Change, 38(3), 261-287.
Zimmerman, F.J. and M.R. Carter, 2003: Asset smoothing, consumption smoothing and the reproduction of inequality under risk and subsistence constraints. Journal of Development Economics, 71(2), 233-260.