A new report of experts from the United Nations showed a correlation between natural disasters, and confirmed that this correlation includes climatic phenomena that seem contradictory and have become more severe and frequent in recent years, such as droughts, forest fires, heavy rains and floods, but they share the same climatic and human causes.
How do these contradictory phenomena arise at the same time and in neighboring regions, and what are the root causes of their occurrence?
The report, prepared by experts from the United Nations University Institute for Environment and Human Security (UNU-EHS), analyzed 10 disasters that occurred between 2001 and 2022, including the heat wave that hit British Columbia in Canada, and Hurricane Ida that hit the coast of Louisiana. , floods in Lagos in Nigeria, wildfires in the Mediterranean and food insecurity in southern Madagascar, and drought in Taiwan.
The report indicated that these phenomena do not occur in isolation from each other.
The report prepared by experts from the United Nations analyzed the disasters that occurred between 2001 and 2022 (websites)
catastrophic consequences of paradoxical phenomena
It is clear from the main findings of the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), released last year, that extreme events - such as droughts, wildfires and floods - are increasingly exacerbated by human impact.
What the UN report refers to is only a sample of the interconnected and sometimes contradictory disasters that the world has witnessed recently.
During this summer, Pakistan lived under the weight of massive floods that killed about a thousand people and displaced millions, while China - the neighboring country - witnessed a severe drought that dried up rivers and lakes and stopped power plants from working, which experts described as the most severe heat wave. registered in the world.
Europe experienced a period of drought described as the worst in 500 years, in the absence of rainfall for more than two months, which led to a record decline in the water level in major rivers such as the Thames in Britain.
Navigation became impossible in some parts of the Rhine in Germany and the Po and Seine in France, and the waters of the Danube were approaching historical lows.
In the summer of last year, Europe also witnessed a paradoxical climatic phenomenon, after unprecedented floods swept through central Europe, causing many rivers to overflow and inundating cities and towns on their banks.
These floods were preceded by record temperatures recorded in the Mediterranean Basin, which resulted in the outbreak of a series of widespread fires in a number of countries, such as Algeria, Tunisia, Greece and Turkey, and the loss of tens of thousands of hectares of forests.
Although phenomena such as heat waves, droughts and fires seem to contradict the phenomena of heavy rains and floods and do not seem to have much in common, they are interrelated with each other, according to the UN report.
Pakistan's recent floods were preceded by a hot summer and coincided with a drought in neighboring China (Reuters)
When drought leads to floods
According to the report, the high concentration of greenhouse gases in the atmosphere - such as carbon dioxide, which amounted to about 419 parts per million, an increase of about 50% compared to before the industrial revolution - is one of the main causes of extreme weather events.
Global warming increases the dangers of drought in several ways, chief among which is the evaporation of water more quickly at higher temperatures.
Hot weather can speed up the drying of soil and plant leaves and convert water into vapor that disperses into the atmosphere through a process called transpiration.
These conditions lead to damage to plants and forest (forest) cover and a lack of surface water resources that accelerate evaporation due to high temperatures, which are characteristic conditions for drought periods, and are suitable for the outbreak of fires in forests.
On the other hand, rising temperatures, according to climate experts, cause more liquid water to evaporate from soil, plants, oceans and waterways, becoming water vapor.
This extra water vapor means that there is more moisture available to condense into raindrops when conditions are right for precipitation.
More moisture causes heavy rain, or heavy snow, during the winter.
Scientists have estimated that every one degree increase in temperature results in an increase in air humidity by about 7%.
Forest fires have been repeated in a number of countries in the world, the latest of which is Algeria's (Shutterstock)
root causes
In addition to the global warming resulting from the increase in emissions of polluting gases in the atmosphere, experts in this report, according to the United Nations News website, monitored a number of anthropogenic causes such as deforestation and urban sprawl, which seem to be common to most of the natural disasters that experts analyzed in the report.
Deforestation, for example, leads to soil erosion, and the lack of trees and roots results in no protection from erosion factors such as wind and rain and can be easily swept away.
This situation creates ideal conditions for many disasters, such as the devastating landslides that occurred during the earthquake in Haiti, the formation of sandstorms in southern Madagascar, and the increased sedimentation of water reservoirs that contributed to the drought in Taiwan.
The report also emphasized that inefficient risk management, underestimation of environmental costs and inequality of development are among the most common root causes of almost all disasters.
On the other hand, United Nations experts stress that the interdependence between these disasters also makes the solutions interconnected, which means that taking one action can help reduce the risks of more than one type of disaster.
Reducing global warming gas emissions and halting deforestation, for example, can help mitigate extreme natural phenomena such as heat waves, floods and hurricanes at the same time.