Twenty years after the ratification of a United Nations treaty on climate change, greenhouse gas emissions from the most industrialized countries lead us to global warming, pointing out the failure of these countries to the detriment of the entire planet. Carbon dioxide emissions rose 11 percent in the 1990s, and will grow another 50 percent globally by 2020. In 1997 with the Kyoto Protocol it was agreed that by 2012, a group (38) of industrialized countries would reduce their emissions by an average of 7 percent below the levels of the year 1990. So far that did not meet, especially the US the largest CO2 producer in the world. Recently, the US renounced the treaty obligations, protecting highly polluting industries. For them, changing energy patterns with a view to reducing CO2 emissions means large investments and reduced productivity that would lead to large emerging economies such as Russia, China, India, Brazil, South Africa. These economies are grouped in the newly created BRICS Bank.
The effects of climate change are devastating. At present the self-regulating capacities of the atmosphere are being pushed to their limits and according to many specialists have already been surpassed. The solutions to the problems of thinning of the ozone layer, global warming and devastating climatic changes are not a matter of years, not even decades. That is why you can not wait for the effects become obvious and clear, because surely by that time it will be too late to act looking for solutions to the irreversible consequences. Venezuela collaborates with the production of ozone in an important way with the well-known Catatumbo Lightning, which acts without stopping every day and night.
What are these consequences of global climate change?
Within the effects of climate change especially for the Caribbean region where Venezuela is located, we can point to hurricanes, storm surges, alteration of climatic seasons and especially the effect of "child" and "girl" that involves prolonged droughts or heavy floods due to a concentration of exceptional rainfall, earthquakes, landslides and landslides, fires.
Hurricanes are strong storms that form in the sea and have winds with speeds of 119 km/h and more. Hurricanes are detected by satellites from the moment they begin to form and therefore there is usually a warning 3 or 4 days before the storm begins. A hurricane covers a circular area between 320 and 770 km in diameter. In the storm there are strong winds and rains that surround the central "eye of the hurricane", which is about 24 km in diameter. The winds of a hurricane can sometimes reach up to 320 km/h. However, the greatest damage to life and property is not the result of the wind, but the rise of the tides and torrential floods. A hurricane is a tropical storm with strong winds that circulate around a low pressure area. When the wind speed reaches 119 km per hour, the storm is officially classified as a hurricane.
The spiral bands of wind and rain that form a hurricane can extend hundreds of kilometers from the eye or vortex (it is a relatively quiet area). When the hurricanes reach warm waters (for example the waters of the Caribbean) then that hurricane grows in danger. We saw it with the hurricane that seriously affected Haiti, Jamaica and many Caribbean islands, as well as affecting the coasts of Venezuela. Other hurricanes like Maria, caused severe damage on the island of Puerto Rico last year. When the storm reaches the mainland, it can generate tornadoes on its shores. The most dangerous part of a hurricane is, however, the storm surge, a gigantic column of seawater, driven by the wind, which floods the coast when the hurricane enters the land. Even if the storm reaches the mainland during low tide, the water level can rise about 6 meters near the coast, although in extreme cases it can reach 13 meters.
In December of 1999, heavy rains produced a landslide in the Edo Vargas of Venezuela, and produced more than 20,000 dead and disappeared apart from enormous material losses. Usually, the heavy rains that are part of the hurricane cause serious floods while the storm is entering the mainland. To this we must add that they can create waves up to 18 meters high. The hurricanes that affect the Caribbean territories have affected the northern part of Venezuela and especially the coastal areas. The hurricane season officially begins in June and ends in November.
On the other hand, the increase in sea level (between 1 to 3 cm per year) due to the thawing of the glaciers will undoubtedly affect the populated regions located near the sea. In addition to these effects, geotéctonics is affected when imbalances are generated by gravitational loads on sea beds, where the thickness of the earth's crust is lower than in the continent. Attending to the regular movements of tectonic plates and isostasy, these variations in sea level can produce increases in these movements with the consequent displacements of plate edge faults, which produce earthquakes and volcanism in the subduction zones. The volcanism in the Caribbean plate is located to the West in the countries of Central America and Mexico.
The volcanism to the East is the arc of the Lesser Antilles. We have seen the reactivation of some volcanoes in Colombia and Ecuador, neighbors of the Caribbean tectonic plate. Also in the orogenic belt of the Pacific has increased the activity of some volcanoes and generation of large earthquakes. Some of those earthquakes, especially those that occurred in Japan and Chile, have produced tsunamis that consist of subsidence of the earth's crust that cause a great wave of more than 20 meters high, traveling thousands of kilometers and affecting distant coasts such as Chile and the South Pacific islands.
How can we evaluate the threat, vulnerability and risk of any natural disaster such as hurricane, flood, earthquake, landslide, etc?
Regardless of the uncertainties of the phenomenon to be considered (flood, hurricane, storm surge, earthquake) or of the knowledge we have of that phenomenon, the quantification of the Threat or Hazard must be done in probabilistic terms. It is usually expressed as the probability of a random variable X that exceeds a value Xo in a period of time t. So we have: P ( X> Xo/t)
The random variable X can be some parameter that characterizes the intensity of the event considered, for example: wind speed for hurricanes, intensity of rainfall measured in millimeters, height of the waves, acceleration of the ground when there is a tremor. Then the Hazard of this or that phenomenon is the probability of exceedance of the parameter that identifies the event considered, in a certain period of time (usually it is annual). The inverse of the annual exceedance probability is the return period of the considered event. Now, the probabilistic function to be considered is a function of the amount of data available. When there is a lot of data, the Gauss model or Normal distribution is used. When there are scarce events such as earthquakes, the extreme Poisson distribution is used. The decision of which to use corresponds to the experts who will work on these quantifications.
To sum up, the probability that a seismic event of a given intensity occurs within a specific period of time and within a certain area is called Hazard or Threat. It is called Vulnerability of geographical area, building, etc., to the degree of damage due to the occurrence of a seismic movement of a certain intensity. Then we define Risk as the consequence of the combination of danger or threat and vulnerability as expressed in the following equality:
DANGER x VULNERABILITY = RISK
Then the Risk increases with the vulnerability factor, considering that the danger is a natural phenomenon that can not be eliminated or reduced. The determination of the risk is made based on the projections of the classes of damages for the different types of geographical areas, buildings, or what will be studied. The risk is usually classified as follows:
High Risk: They will probably have great damage.
Medium Risk: They will have moderate damage.
Low Risk: Probably they will not suffer damages or they will suffer slight damages.
What is the situation in Venezuela in the face of the consequences of global climate change?
Venezuela is located in the North of South America and belongs to the Caribbean area. For this reason the natural disasters that have occurred, occur and affect the country as a result of climate change. They can be classified into:
a. Floods due to the occurrence of heavy downpours.
b. Landslides of mountains skirts due to the water saturation of the ground motivated by heavy showers of great duration.
c. Hurricane winds during the rainy season, between June and November.
d. Destructive earthquakes, because Venezuela is located between the tectonic plate of South America and the tectonic plate of the Caribbean (fault system of Boconó and San Sebastián, with more than 2000 km long).
Swells with big waves due to hurricanes in the Caribbean Sea in the North of the country.
The damage produced is basically on the residents of the different areas susceptible to suffer the natural events mentioned, and the damage to movable property, on residential and office buildings, on roads and bridges, on ports and airports, on the sowings, on the industries, as well as the damages on the electrical services, of potable water, of domestic gas, of communications as much roads as of telephone transmission, of fax, data and Internet.
Does Venezuela have adequate prevention systems for all these natural disasters caused by climate changes?
Unfortunately not for all the events mentioned. Venezuela has seismic resistant standards for the design of structures to resist earthquakes, for which it is prepared so that its buildings, bridges, dams, industrial works, etc., can withstand moderate to strong earthquakes, according to the geographical seismic zone in the which is the specific work. But fire prevention suffers from supervision and implementation in different susceptible areas. Perhaps the Petroleum Industry was prepared and organized to efficiently attend the fire emergencies in its facilities, but it is an exception when we evaluate the risk in other strategic installations. Today PDVSA is not prepared to efficiently and effectively address the risks that affect facilities, refineries, injection plants, pumping systems and polyduct networks.
With climate changes as a result of CO2 emissions and global warming, hurricanes have increased in the Caribbean, whose trajectories have slightly affected the Venezuelan coasts and some islands. Although for the constructions we have demanding seismic codes, the resistance checks against hurricane winds of, for example, more than 200 km per hour are not required. Of course, a reinforced concrete or steel structure building will be able to withstand such attacks, but the non-structural damage can be great and there is no need for it, especially for the roofs of humble dwellings located on the coasts of the Caribbean Sea.
Neither is Venezuela prepared for swells with waves over 6 meters high. These events were not known in our country. With the acceleration of the effects of the warming of the earth these phenomena have been presented with considerable damage to property and some loss of human life.
However, Venezuela has an integrated system of attention to natural disasters, led by Civil Defense, where the National Armed Forces, the different Fire Bodies, the Ministry of the Environment, the Ministry of Health, the Ministry of Infrastructure and the Ministry of the Interior participate. and Justice through the security forces. The experiences of the Edo landslide. Vargas in December 1999, consolidated all these groups plus an immense group of volunteers, both national and international.
What can be done to prevent and reduce vulnerability to these natural disasters?
The first thing that must be done is to evaluate the elements of Threat or Hazard, the Vulnerability and the Risk before these events. For this it is necessary to create multidisciplinary commissions to compile data and classify them, order them and model the probabilities of occurrence versus time. This will determine the Danger of geographic zones and islands, before the occurrence of hurricanes, tidal waves, floods, fires, isolation of communications by roads through landslides, paralysis of ports and airports, etc.
With the determination of the Danger of the events, the experts can classify the Vulnerability of the different zones and constructions that are in them. Likewise, risks can be quantified. With them, you can study how to reduce them through concrete actions in the short, medium and long term. This task can not be postponed and must be undertaken by the national government through the institutions to which this responsibility corresponds.
Short-term actions must be implemented through local and regional governments, with specific budgets to reduce these vulnerabilities. Medium-term actions refer to the creation of mandatory national and local regulations, as well as the incorporation of those old buildings and facilities to comply with those standards. Long-term actions refer to research and development programs for new techniques to reduce risks and vulnerabilities.
These research and development programs should be included in the macro programs of the multilateral institutions dedicated to these tasks, in such a way that there is a reciprocity and exchange of technologies and methods to standardize the methods and units to be able to attack and solve those problems with the contest of several countries of the area.