Impacts on the natural environment
The temperature has increased significantly throughout Latin America, between 0.7 °C and 1 °C since 1970.[2] An increase in temperature is also observed at the extremes. There is an increase in the average temperature on the warmest days. The Fifth IPCC Report indicates that under all SRES scenarios and all RCP trajectories, the temperature by the end of the century in Latin America will increase,[2] with differences in the specific increase according to the scenarios and trajectories.
• - Climate map of the Caribbean, according to the Köppen-Geiger climate classification, belonging to the period 1980 - 2016.
• - Climate map of the Caribbean, according to the Köppen-Geiger climate classification, projections for the period 2071 - 2100.
• - Climate map of South America, according to the Köppen-Geiger climate classification, belonging to the period 1980 - 2016.
• - Climate map of South America, according to the Köppen-Geiger climate classification, projections for the period 2071 - 2100.
In 2019, the Intergovernmental Panel on Climate Change (IPPC) published a special report on the Ocean and Cryosphere in a Changing Climate.[11] From that report, the Climate and Development Knowledge Network synthesized the information and extracted the key messages for Latin America into a guide.[12] Among these messages, it is indicated that high mountain frozen lands in Latin America They are melting and this has consequences for society.*.
Glaciers located in tropical areas have experienced sustained retreat over the last three decades, intensifying the retraction trend.[2] This glacier loss has accelerated since 2010, especially in the Andes Mountains of Argentina and Chile.[13] The situation is particularly critical in tropical Andean glaciers,[2] which are the main source of fresh water for agriculture, hydroelectric energy and human consumption in countries such as Peru, Bolivia, Colombia and Venezuela.[14] The retraction of glaciers in these areas causes landslides and changes in the courses of rivers, threatening the populations in the lower areas of the mountains.[12].
Watersheds and watersheds suffer far-reaching local and regional impacts due to changes in the cryosphere.[12] Runoff into glacier-fed rivers is decreasing and this process is irreversible. Small glaciers found in the Andes are projected to lose 80% of their current ice mass by 2100 under high emissions scenarios.[12] Melting glaciers and permafrost are expected to release heavy metals, especially mercury, which will reduce water quality for freshwater organisms, as well as for domestic and agricultural use.
High mountain ecosystems, including plant and animal species, are already being affected as ice and snow melt and retreat. Movements of species from lower altitudes to higher altitudes in the mountains are being observed, and some species will be left without a habitat with a suitable climate to survive.[12].
Natural disasters in high mountain areas have increased. Landslides, as a result of the melting of the cryosphere, are affecting people and infrastructure. In the coming decades, this glacial retreat is projected to make slopes less stable and increase the number of glacial lakes. There will be floods due to violent overflows of glacial lakes, landslides and snow avalanches in new places and in different seasons.[12].
The region receives 30% of the world's precipitation and a third of the world's renewable water resources, with vast basins such as the Amazon River and the La Plata River. However, the spatial and temporal distribution of precipitation is very heterogeneous, generating difficulties in accessing water.
Precipitation increased in southeast Brazil, east-central Argentina, Uruguay, Paraguay, Bolivia, northwest Peru and Ecuador; while they decreased in south-central Chile, northwest Brazil, southern Peru, and part of Central America and Mexico.[8] These increasing and decreasing trends in precipitation, as well as the shortening of the rainy season, the increase in the frequency and intensity of extreme hydrometeorological events, greater frequency of severe hurricanes and increase in mean sea level,[15] are already changing in the climate system of Latin America, with increases in flooding and in droughts. The southeastern region of South America has experienced an increase in precipitation, while the central and southern region of Chile is experiencing an increase in droughts.[2].
By mid-century, rising temperatures and declining soil moisture are expected to see savanna gradually replace rainforest in the eastern Amazon basin. By the end of the century, warming in South America is expected to reach 4°C with reduced rainfall in the tropical region and increases of 15 to 20% in southeastern South America, as well as the number of warm days and nights and heavy rainfall expected to increase.[8] Changes in precipitation patterns and melting glaciers will significantly affect the availability of water for human consumption, agriculture, and energy generation.
In drier areas, climate change will likely worsen drought, causing salinization (increased salt content) and desertification (land degradation) of agricultural land. The productivity of livestock and some important crops such as corn and coffee is expected to decline, affecting food security. In temperate zones, soybean yields are expected to increase. Rising sea levels will increase the risk of flooding, displacement of people, salinization of drinking water resources, and coastal erosion in low-lying areas.
Impacts on people
The unequal distribution of income in the region generates high levels of poverty, especially in rural areas, increasing vulnerability to climatic conditions.[8] 25% of Latin America's exports come from the agricultural sector.[9] One of the biggest challenges for the region is the high degree of primarization of the economies.
The impact of climate change on Latin American countries is significant due to their dependence on agriculture and natural resources, their low adaptive capacity in various segments of the population, as well as the geographical location of some countries.[8].
Agricultural production in the southeastern region of South America is expected to be sustained or increased until mid-century. In the central region of Chile and the central west of Argentina, food security would not be affected, while in the northeast of Brazil, part of the Andean Region and Central America, food security could be affected due to the decrease in crop yields and local economies.[8] Different models show that there will be a reduction in yield in the main grain crops in Latin America and parts of the Caribbean.[16] This will not only affect the economy but will also put their food security at risk. countries.[9][16].
On the other hand, displacements in altitude and latitude of the areas for cultivation and an increase in diseases are expected, which would harm the poorest sectors of the region. This situation could be aggravated by the retreat of glaciers, reduced precipitation and increased evapotranspiration, triggering in turn greater vulnerability in water supply in semi-arid zones and the tropical Andes for food production and other uses.[8].
Deforestation, due to the expansion of agricultural activities, has aggravated the process of soil degradation, the loss of biodiversity and the increased vulnerability of communities exposed to floods, landslides and droughts.[8] The high degree of desertification already existing in Latin America constitutes a risk for food security in the region.[12] The Special Report on Climate Change and Land warns of a decrease of 8% to 14% of agricultural product as an effect of the desertification.[12].
Agriculture is one of the main causes of deforestation worldwide. Beef production occupies about 80% of arable land, either directly in pastures, or indirectly in crops, such as soybeans used to feed livestock. Latin America and the Caribbean participate significantly in this dynamic, with the highest per capita beef consumption in the world,[17] being also an important region in food exports.[18] It is estimated that 15% of greenhouse gas (GHG) emissions from the food system in Latin America and the Caribbean correspond to exports to the rest of the world. Additionally, 21% of the land used for agriculture and livestock and 19% of emissions from deforestation in the region are related to these exports.[19].