Climate crisis brings high temperatures, but no drought in Argentina and Uruguay

There climate crisis drove the high temperatures but not the drought in the agricultural regions of Argentina and Uruguay, however, it was not the main driver of reduced rainfall causing the drought that has plagued the region for months, according to a rapid attribution analysis by an international team of leading climate scientists in the world. part of the World Weather Attribution scientific group.

The analysis also showed that if climate change increases the temperatures in the region and aggravated the effects of the drought, it did not make low rainfall more likely. Since 2019, the central region of South America has shown an unusually low level of precipitation. So much so that the center of Argentina has registered its year in 2022 drier since 1960, with the region receiving about half of its average rainfall in the last four months of the year.

This, combined with the high temperatures, caused losses widespread harvests. In Argentina, export earnings from grains and oilseeds have fallen by around 60% in 2022 due to crop losses and disruptions to maritime transport caused by the low water level of the Paraná River. And in 2023, agricultural exports are expected to continue to fall by 28% compared to 2022 levels. Uruguay declared an agricultural emergency in October 2022, since 60% of its territory suffers from a “extreme” or “severe” drought.

“East multi-year drought raised concern among society, farmers and policy makers in much of South America. Although, with the methods available for attribution of extreme events, we did not find a clear relationship between rainfall deficit and climate changethe appearance of successive heat waves in recent months could lead to an increase in the impacts of the drought,” he explained. john riveraArgentinian scientist from Argentine Institute of Snow, Glaciology and Environmental Sciences (IANIGLA) and one of the authors of the research paper.

The experts explained, during a press conference, that the drought phenomenon is attributed to the influence of the cold Pacific current, La Niña, which for three years has been more or less constant. And they clarified that the climate change this could potentiate these effects.

Paula Arias, Professor of the Engineering and Environmental Management Group (GIGA) of the Antioch Universityin Colombia, co-author of the report said: “Although our analysis did not find a direct effect of climate change on the scarcity of precipitation, we cannot exclude that other factors related to human activities, such that deforestation in the Amazon or in the region of big chaosthey could have influenced”.

The region also experiences intense heat waves whose frequency, intensity and duration have been increased by climate change. In an earlier study conducted in a coincident area, scientists from the Global Weather Allocation found that human-induced climate change was causing extreme temperatures in December 2022, they would be about 60 times more likely. Another unprecedented heat wave is currently raging in the region.

As noted, an important factor in the low rainfall is that South America is currently experiencing the effects of its third consecutive year of La Niñaa weather phenomenon that increases the likelihood of high temperatures and less precipitation in the region.

According to the latest assessment of Intergovernmental Panel on Climate Change (IPCCfor its English terms), Climate change has not had a substantial impact on La Niña, although models predict that rainfall variability associated with La Niña and its El Niño counterpart will increase in the region in the future. Other research has shown that deforestation affects rainfall levels, including increased drought, although scientists did not examine this aspect in the attribution study.

“There is no doubt that climate change plays a role in the high temperatures that Argentina and other countries in the region are currently experiencing. Regarding drought, our analysis suggests that natural variability and the unusual occurrence of three consecutive years of La Niña could explain the low rainfall, but the high temperatures exacerbate the impacts that we see in particular on crops. It is important to detect what is generated by the climate crisis and what is not, in particular to be able to work better on adaptation plans,” he explained. Friederike Otto, Lecturer in Climate Science at the Grantham Institute for Climate Change and the Environment at the Imperial College London.

The researchers also looked at the role that high temperatures caused by climate change might have played in the drought. Specifically, they tested whether the high temperatures recorded in the region may have decreased the water available at the surface, taking into account the role of evaporation when water reaches the ground. They concluded that the increase in temperature compensates for the increase in precipitation and, in general, does not cause a change in the effective precipitation.

But higher temperatures in the region at the end of 2022, which have been attributed to climate change, have decreased water availability in the models, indicating that climate change has likely reduced water availability during this period, increasing dryness. agriculturalalthough the study was unable to quantify this effect.

“The severe impact of the drought on agriculture and economic activity speaks to the need to reduce drought vulnerability in this region. Measures such as improving water efficiency and water management, anticipating drought through seasonal forecasts, and insurance to help farmers cope with dry years could improve resilience to these types of events.

The study was conducted by 18 researchers from the group Global Weather Assignment, Among them are scientists from universities and meteorological agencies from Argentina, Colombia, France, the Netherlands, the United Kingdom and the United States.

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