Article by Teresa Pinto | Biologist and Master in Conservation | 14ºC
Natural disasters are a topic that accompanies us and that is gaining some visibility and even global reach. As the name implies, they are natural and some cyclical events – usually physico-chemical, meteorological or astronomical – that occur since the beginning of Earth's life and without human intervention. Of course, as with other natural topics (extinction of species, for example), the human hand tends to increase the speed and intensity with which these happen. When a natural event has adverse social effects – fatalities, destruction – it is called a natural disaster. And what are they?
LANDSLIPPING / SINK AND COLLAPSE
This category includes soil movements, whether in the flattening of the land and deepening the same, or other movements such as falling cliffs or unstable clay pockets.
CYCLONES, HURRICANES, TORNANS AND TYPHOONS
These nomenclatures address the same natural event: an area where atmospheric pressure is low. The cyclone, although its diameter can reach 1500km, has speeds equal to or greater than 120km/h. The diameter of the tornado does not exceed 2km, but its column spins at close to 500km/h. Warm and humid air rises in design, cyclone or anticyclone currents, of rains and winds that can reach devastating speeds and have destructive consequences.
It can happen on land or in the ocean and has different names depending on that and depending on its geographic location in the hemisphere. One of the best known in recent years is Hurricane Katrina and the one that has caused the most damage to date.
Intense rainfall that is not absorbed back into land or due to runoff mechanisms. It can happen the overflow of rivers, or even given to the melting of accumulated snow. Sometimes it is so intense that it takes vehicles, trees and other high-dimensional objects.
Storms can range from ice, rain, sand, lightning – and all can have a prolonged occurrence and lead to other natural disasters.
A tsunami or tidal wave is characterized by giant waves, caused by an earthquake or volcano of maritime origin. They can roam huge densely populated coastal areas and leave unrelenting destruction.
Earthquakes or earthquakes are violent movements of gigantic land masses associated with the movement of tectonic plates or volcanic eruptions that release large amounts of energy. They have an epicenter and can be felt thousands of kilometers away. The magnitude and damage caused by earthquakes are defined by the Richter scale.
Can open holes from kilometers away, where parts of cities can sometimes disappear. It is considered the deadliest natural disaster, although not the most frequent.
Volcanism can have multiple origins and multiple outcomes. Its diversity is enormous. It can occur on land or at sea, associated with hotspots where magma is released; between tectonic plates, fissure volcanism and the best known, to mountain ranges with a volcanic cone. It can give rise to effusive eruptions, whose magma is extremely fluid and at higher temperatures, such as explosive eruptions with more viscous magma, gasified and associated with a lot of smoke, clouds of dust and pyroclasts (rock fragments projected at high speed and great distances). ).
Droughts are also diverse – they can be permanent, seasonal, irregular or invisible. They are characterized by a lack of rainfall that lasts long enough to damage crops and lead to the death by hunger and thirst of various animals and people.
Among other natural catastrophes, such as:
FOREST FIRE, EPIDEMICS AND PANDEMICS, METEORITES FALL, WIND BLASTS
AND IN THE LAST YEARS, WHAT HAS BEEN HAPPENING?
IN THE PAST 50 YEARS, NATURAL DISASTERS HAVE FIFTHLY
According to the World Meteorological Organization (WMO), with the development boom of countries in the last century, developed countries are the least affected (9%) by natural disasters compared to 91% of disasters that occur in developing countries. development Prior monitoring, better living conditions and preparation of buildings and structures for these events meant that the mortality associated with them – in the last 50 years – was three times lower, as we can see in the graph. Even so, there are thousands of people affected who are left homeless, without sanitary conditions, without access to basic food or health care.
However, climate change has been increasing the frequency of these events to 5 times more and causing seven times more damage than in the 1970s, reports the UN – with 711 disasters recorded in 1970 and 3,536 in 2009.
About 90% of disasters in the last 20 years were caused by 6457 floods, storms, heat waves, droughts, among others, launches the report by the United Nations Office for Disaster Risk Reduction (UNISDR). He adds that the most affected countries are the United States, the Philippines, Indonesia, China and India. The number of victims, although it has decreased considerably, were counted as 650 000 deaths due to droughts, 577 232 to storms, 58 700 to floods and 55 736 to extreme temperatures in the last 50 years.
The most relentless and most prominent natural disasters have been on the rise, but those that seem smaller and more insignificant have become the most worrying and far-reaching.
These numbers are frightening even though the planet has increased its temperature by what seems like a “small” degree. The hottest years in history have taken place since 2015 – with 2020 the second warmest year on record – and, if the multiple proposals of world countries to reduce the planet’s temperature are not met, there could be a 3.2ºC increase in it. It is estimated and is beginning to be seen that these phenomena will be increasingly frequent and severe with the increase in global temperature, rising sea waters, greenhouse gases.
This correlation turns out not to be one-sided and linear, but a metaphorical fireball. Climate change causes an increase in natural disasters, which by themselves, with fires and heat waves, contribute to an increase and retention of greenhouse gases that exacerbate climate change and so on.
UNISDR report links 9 out of 10 natural disasters to climate change. Did you know that the Pacific Ring of Fire is a boundary zone between tectonic plates, characterized by the greatest volcanic and seismic activity on the planet and that encompasses all the following countries: Japan, Alaska (USA), Canada, USA, Mexico, Guatemala, Rica, Panama, South America, Thailand, Indonesia, Philippines Malaysia, East Timor, Papua New Guinea, Solomon Islands, Vanuatu, Tonga, New Zealand, Taiwan and part of Antarctica?