On the 10th local time, the heavy rain brought by Hurricane "Daniel" hit Africa. Devastating flooding occurred in Libya, causing a large number of casualties. Egypt's meteorological service has issued warnings for possible rainfall and severe weather. Africa is one of the world's least emitting emitters of greenhouse gases, but it is the continent most affected by climate change. At the first Africa Climate Summit last week, African heads of state hoped that the international community should increase financing and technical assistance to Africa and seek "solutions for climate finance".
On September 17, 2023, local time, Hurricane Daniel hit Derna, Libya, causing severe flooding.
Africa's climate crisis
In recent decades, Africa's temperature has risen at an accelerated rate, and weather- and climate-related natural disasters have become increasingly severe. In 2022 alone, more than 110 million people on the continent were directly affected by weather, climate and hydrological natural disasters, causing economic losses of more than US$8.5 billion. According to statistics, natural disasters related to weather and climate have caused up to 5,000 deaths, of which 48% are related to drought and 43% are related to floods. The actual data may be much larger than that. "The African continent is the region with the least capacity to cope with the negative impacts of climate change. Heat waves, torrential rains, floods, tropical cyclones and prolonged droughts are having a devastating impact on economic development and livelihoods in Africa, where the number of people at risk of climate change is increasing. World Meteorological Organization Secretary-General Petteri Taalas said.
On November 9, 2022, local time, many animals died in villages near Lake Magadi in Kenya due to drought.
On February 7, 2023, local time, people transported firewood in small boats in Bentiu, South Sudan. South Sudan has been hit by floods for four consecutive years, inundating two-thirds of South Sudan.
Moreover, the climate crisis is having a serious impact on Africa's food security, ecosystems and economic development. In the case of agriculture, the backbone of Africa's national economy, Africa's agricultural productivity growth has fallen by 34% since 1961 due to climate change. Africa had the highest decline compared to the rest of the world. African countries' annual food imports are expected to triple by 2025, increasing the amount of money imported from $35 billion to $110 billion. In addition, climate change and the resulting dwindling natural resources could trigger conflicts over productive land, water and rangeland. Over the past decade, violence among farmers and pastoralists has increased in sub-Saharan African countries due to increasing pressure for land resources.
On October 13, 2022, local time, in Samburu County, Kenya, Nalangu Lekumit, crying while holding his son who fainted because of hunger.
Sharp fluctuations from drought to heavy rainfall are becoming frequent
In many parts of the world, drastic fluctuations from severe droughts to heavy rainfall are becoming more frequent with climate change. Such sharp fluctuations between extreme hydrological events – in many cases devastating torrential rains (flood events) – end prolonged droughts – have a huge impact on water resources and agricultural productivity. As the climate warms, this fluctuation has become more common over the past four decades. A study published in the British journal Communications-Earth and Environment found that this trend is increasing in seven regional hotspots in the world through meteorological and hydrological data over the past four decades: Eastern North America, Europe, East Asia, Southeast Asia, Southern Australia, Southern Africa and Southern South America.
Spatial-temporal patterns of total number of drought and flood event transitions (DPTs) from 1980 to 2020. (Qing et al., Communication - Earth and Environment, 2023) Cartography Wang Yu
In recent years, Africa has seen many disasters that have suddenly transformed from severe droughts into potentially dangerous rainstorms. In March 2023, Cyclone Freddy continued to affect Malawi, Mozambique and Madagascar, causing natural disasters such as floods, windstorms, landslides and mudslides due to heavy rainfall and strong winds, killing more than 220 people and displacing tens of thousands in the three countries. In addition, heavy rainfall from tropical cyclones has led to cholera outbreaks. There are many factors that can contribute to sudden changes in climate and weather, including El Niño and La Niña climate patterns and climate change itself.
May 6, 2023, local time, Tunisia, overlooking a wheat field affected by drought. Rainfall was at its lowest in recent years, and drought affected local food production and livestock.
On September 19, 2022, local time, in Hadegar, Nigeria, torrential rains caused flooding, flooding farmland, and people passing on waterlogged roads.
On March 16, 2023, local time, Malawi, Tropical Cyclone Freddy brought heavy rainfall and triggered local landslides and mudslides.
In an article published in the journal Nature in July this year, a research team used causal inference methods to detect the causal chain of transport between soil moisture, latent heat flux, water vapor convergence and precipitation to explain drought and flood transitions. It was found that in wet and arid regions, the transmission of causal chains has different roles in triggering the occurrence of drought and flood transitions.
The soil moisture-latent heat flux-precipitation causal chain is likely to trigger rainfall after drying in humid areas, where enhanced evaporation increases actual atmospheric humidity and favors flooding. This causal chain is triggered by drying out the soil and vegetation, which causes the air to become hotter, which in turn increases evaporation demand, potentially enhancing the latent heat flux at the surface and increasing atmospheric moisture content. In addition, in the case of global warming, because more energy is distributed to sensible heat, rising temperatures increase the water-holding capacity of the atmosphere, allowing the air to retain more moisture. Therefore, the increase in atmospheric water content and the increase in the water-holding capacity of the atmosphere may lead to rainfall or even heavy rainfall. ”
Explain the proposed mechanism of the transition from drought to flood in terms of soil moisture-atmospheric feedback. (Qing et al., Communication - Earth and Environment, 2023) Cartography Wang Yu
In contrast, while soil moisture limits evaporation in arid areas and reduces water recycling for precipitation, a decrease in soil moisture can enhance water vapor convergence, which provides water vapor for rainfall after drought. Therefore, the soil moisture-water vapor convergence-precipitation causal chain enhances post-drought rainfall in arid areas under the action of atmospheric circulation dynamics. In addition, the likelihood of a sudden transition from drought to dangerous rainstorms increases by 0.24% to 1.03% per year, depending on location. At the same time, there has been an increasing risk of sudden transition from drought to flood conditions in recent decades.
On March 23, 2023, local time, people in Dadaab refugee camp, Kenya, people fetching water. The World Health Organization says Somalia, Africa, is suffering from its worst drought in 40 years, with 400 to 500 people arriving in the camps every day.
To combat climate change, Africa needs assistance
Africa is one of the world's least emitting emitters of greenhouse gases, but it is the continent most affected by climate change. The role of African countries in addressing climate change cannot be ignored. Today, climate change has entered a new era, which is no longer just about solving environmental or development problems, but about solving a series of challenges brought about by climate change in the context of fairness and justice. Many African countries are facing the threat of climate change and urgently need financial and technical support to further unleash their green development potential. The international community should increase financing and technical assistance to Africa to help African countries transition to low-carbon and climate-resilient economies.
On September 6, 2023, local time, Nairobi, Kenya, at the first African Climate Summit held at the Kenyatta International Conference Center, Kenyan President William Ruto and leaders of participating countries held a press conference.
Source: Xinhua News Agency, CCTV News Client, Visual China