Challenges in rural and urban areas
Climate change will exacerbate agricultural losses, increase the challenge of generating hydroelectric power and affect urban management
“We must take action to prevent the worst,” Eduardo Assad said in April at a conference in São Paulo where he presented the findings of one chapter of the first report by the Brazilian Panel on Climate Change (PBMC). He is an agronomist and researcher with the Brazilian Agricultural Research Corporation (Embrapa). The researchers hope that the information in the report will serve as a guide for the development and implementation of public policies and planning by businesses. “With our report,” says Tércio Ambrizzi, of IAG-USP, one of the coordinators of the PBMC, “we are better able to see the areas where we are doing well and those where we need to focus more attention.”
The challenges identified in the Brazilian report are many. “We have to change agricultural, industrial and urban policies, including concern for sustainability and extreme climate events such as droughts and rains,” says Antonio Magalhães, advisor to the Center for Strategic Studies and Management (CGEE), attached to the Ministry of Science, Technology and Innovation (MCTI). “We need to broaden the debate and overcome institutional rigidity, resistance and short-term interests.”
The report points out that the consequences of the increase in the average global temperature will be dramatic in Brazil. According to the computer simulation models for climate, agriculture will be the sector most affected because of changes in rainfall patterns. “Even if the amount of rain remains unchanged, the amount of moisture in the soil will decrease as a result of the rise in mean annual temperature, which intensifies evapotranspiration,” says Magalhães. According to him, this phenomenon will adversely affect crops in regions where water scarcity is already constant, such as in Brazil’s semi-arid northeast.
“In Northeastern Brazil,” the report predicts, “corn, rice, bean, cotton and cassava crop productivity will be significantly lower due to a sharp reduction in areas at low-risk.” One likely consequence of reduced agricultural production and land area suitable for agriculture would be declining income for the population, intensifying poverty and migration from rural areas to the cities, which in turn will exacerbate infrastructure problems, such as housing, schools, health, transportation and sanitation.
The effects on agriculture can already be measured. “Since 2000 we have observed a drop in production in some regions, particularly in coffee, soybeans and corn,” says Assad. According to him, with the rise in temperature, losses in agricultural productivity caused by climate change have already reached R$5 billion per year—and are expected to grow. The prediction by a 2008 Embrapa study, one confirmed by the PBMC report, is that climate change will affect food production and cause losses estimated at R$7.4 billion by 2020 and R$14 billion by 2070, thus harming agribusiness which accounts for 24% of national GDP. Soybean crops are likely to be the most affected, with losses of up to 40% of the planting area. Arabica coffee production is expected to decline 33% in São Paulo and Minas Gerais, although it may increase in the South. Forecasts indicate that by 2020 and 2030, there will probably be a reduction in the production of cotton, rice, beans, soybeans, corn and wheat—the effect of the expected rise in temperature.
“Between 1990 and 2010, rainfall intensity doubled in the Cerrado region,” says Assad, “and the current technological model for agriculture has not yet adapted to these new patterns.” Assad says it is now imperative to invest intensively in agricultural intercropping systems, and not just in single-crop agricultural production, in order to increase biological nitrogen fixation, reduce the use of fertilizer and expand crop rotation. “We already know how to do this, but we need stronger governance,” he says. “We need to increase agricultural productivity in the Midwest, Southeast and South, to prevent the destruction of Amazonia. The reorganization of rural Brazil is now urgent.”
More pests and deseases
More frequent and intense floods and droughts are likely to cause a reduction in agricultural production for another reason. Researchers at Embrapa’s Environmental Division, located in the city of Jaguariúna (São Paulo State) concluded that some diseases—mainly those caused by fungi—and pests may worsen for many of the 19 crops they analyzed, including soybeans, corn, coffee, rice, beans, banana, mango and grapes, since climate change scenarios predict higher levels of CO2 in the air, higher temperatures and more ultraviolet B radiation. This creates the possibility of higher prices and a reduction in the variety of cereals, vegetables, and fruits available. Another possibility is the migration of diseases such as the black sigatoka fungus, the most worrisome of the banana diseases, which are likely to lose intensity in some regions, but emerge in others where it has not yet manifested itself (see Pesquisa FAPESP Issue No. 198).
More intense and frequent floods and droughts, according to the PBMC report, will also change the flow of rivers and threaten the supply of water from reservoirs needed for hydroelectric power, accelerate the acidification of sea water, and reduce Brazil’s aquatic biodiversity. The loss of biodiversity of Brazil’s natural environments will worsen; some have already lost significant area—the Cerrado, 47%, and the Caatinga, 44%—to the point that experts doubt whether the recovery of ecological balance characteristic of these environments would even be possible.
People who live in cities, particularly in coastal areas, will have to be concerned about the increased risk of landslides, even heavier rain showers, and the possible effects of a rise in sea level. More intense heat waves are also expected, which may increase mortality rates especially among people with cardiac and respiratory diseases, and insects carrying dengue fever and malaria are likely to proliferate because of the higher temperatures. “If we do not prepare ourselves for the possibility of intensified heat and humidity in the cities,” warns Assad, “we are likely to have more public health problems.”
What to do?
The working group coordinated by Assad and Magalhães suggested measures that cities could take in order to adapt to inclement weather, such as creating linear parks around streams, controlling erosion in coastal cities, where 85% of the population live, and the relocating residents in at-risk areas, to reduce the impact of floods and prevent the type of Dantesque flooding that occurred in the city of Petrópolis two years ago. “I’ve been going to Rio de Janeiro for 50 years, but only after a thousand people died in Petrópolis did I see street sweepers cleaning storm drains in Copacabana,” says Assad. “The mayor of one Minas Gerais city instituted measures against floods, collecting garbage and cleaning storm drains. There was no flooding in his city for the next two years, but in the third year the preventive measures were discontinued.”
“The uncertainties are no justification for postponing decisions on how to mitigate greenhouse gas emissions,” says Mercedes Bustamante, a professor at the University of Brasília (UnB) and coordinator of the team that examined the prospects for reducing the impacts (mitigation) and adapting to climate change. Emilio Rovere, a professor at the Federal University of Rio de Janeiro (UFRJ), who also led the team that prepared this part of the report, acknowledged (1) “the near impossibility of stabilizing the temperature at just 2 degrees above the pre-Industrial Revolution level,” (2) “the feasibility of reaching the voluntary targets to limit emissions already approved by the Brazilian government”—reducing greenhouse gas emissions by 36-38% by 2020, announced in December 2010, by reducing deforestation, recovering degraded pastures, and introducing environmentally sustainable agricultural, environmental and energy policies—and (3) “the trend toward a resumption of growth of Brazilian emissions after 2020, if additional mitigating measures are not approved.”
The experts in this group believe that it is indeed possible to reconcile the reduction of greenhouse gas emissions with economic development. “The government is not standing still, but its actions have been timid,” says Assad. The federal government promoted the first wind and solar energy auctions, but ethanol, an alternative that is less polluting than fossil fuels, is still deemed less important, he says. An important initiative is the Low Carbon Agriculture (ABC) program, which allocated R$3.5 billion in funding for the 2011/2012 crop in order to encourage farmers to reduce greenhouse gas emissions, through no-tillage planting on freshly harvested straw, rehabilitation of degraded pastures for food production and encouraging the integration of forests, livestock and crop farming. As a result of the Plan for Prevention and Control of Deforestation in the Amazon, deforestation fell from 27,000 km2 to 4,000 km2 in less than 10 years, but changes to transportation patterns happen slowly. “We need more trains, subways and bike paths, we can no longer rely on individual modes of transport, especially in cities,” says Assad.
The report’s authors recognize that dialogue is growing. Former opponents, such as farmers, are now allies. The National Action Plan on Climate Change and the fact that the United States government has recognized that climate change is a problem will accelerate the implementation of effective policies in this area. “All spheres of government, industry, commerce and society need to be involved in developing an adequate national response,” says Assad. Magalhães of the CGEE recognizes that articulating this response is still just beginning, although concern about climate change is growing.
“When we started the discussion internationally on climate change, especially after the Intergovernmental Panel on Climate Change (IPCC) was created in 1989, the subject failed to resonate with decision makers in Brazil. It took more than a decade for the country to react,” says Magalhães. “There is now a National Commission on Climate Change, a National Forum and State Forums, which include civil society. A National Plan and sectoral plans are now being developed to adapt to those changes that are inevitable. Various ministries and institutions have already planned their actions, but there is still a lack of effort and more consistent responses are needed. This movement to articulate these responses is growing. The future is bound to be different, because the government is a reflection of what society wants.”