Man, from the beginning has been moving from one place to another. He is known to change his habitat according to his needs and conveniences. Migration therefore, is phenomenon synonymous with living things. An individual seeking to flee a cataclysmic event such as the volcanic eruption in Monstserrat that began in1995, or central America’ Hurricane Mitch in1998, or the 2010 earthquake in Port-au-Prince, is in a different postion than a secon individual seeking to escape an ecosystem in decline because of willful policies such as dam building or strategic defoliation during war.
Today people move basically for economic reasons, agricultural reasons, work opportunities, natural disaster and political instability. Today, establishing facts shows that the reform in climate has become a constituent part of human migration. The process of moving within or across borders, either temporarily, seasonally or permanently and it is usually linked with segment of choices, and it is considered to be voluntary in nature.
I would like to explain in details the interaction between migration and climate change.
In tackling the subject matter, I will first of all tackle migration as a topic by giving its definition, its types, factors and its effect; then climate and climate change in explaining climate, its definition, types, classification of climates and then the relation of migration and climate change.
Migration is the permanent or temporary movement of people from one place of abode to another. Migration is categorized into emigration (this is a one-way motion where of mankind go to one location), immigration (is a one-way inward movement of people into a place), rhythmic, periodic or seasonal migration.
In a nutshell, migration is a generally the inward and outward movement of people in a place.
Types of Migration
- Rural-rural migration: this occurs when people move mostly labours from one rural, agricultural area to another. It occurs generally during farming seasons.
- Rural-urban migration: this happens when human race go from rural to metropolitan zones often for better economic opportunities.
- Urban-rural migration: this happens of people from the urban areas to countryside, either for agricultural production or to settle permanently on retirement or for other reasons.
- Urban-urban migration: this happens when mankind go from one urban area to another in search of better employment opportunities or for other reasons.
- International migration: this is the movement of people from one country to another for labour, economic or political reasons or to escape from natural disasters like earthquakes, volcanic eruptions, drought, and famine. People who are forced to go to countries other than their own to seek protection are called refugees.
- Transhumance: this is the movement of animals and people from associated with a farming practice, whereby cattle are driven up up to higher elevations to graze in summer and return to the valley in winter for better (warmth) climate and pasture.
- Nomadism: this is the seasonal movement of herdsmen from one place to another in search of water and better pastures. Nomadism is practiced by the Fulani cattle rears of West Africa and by the somalians in East Africa.
- Tourism: this is the movement of people within the same countries and also from one country to another to visit places of historical, cultural attractions, and relaxation centers.
- Migrant labour: this is an important type of seasonal migration which involves the movement of labour to areas of agricultural, industrial and mining activities.
Factors of Migration
- Economic factors: areas of the better economic opportunities are generally known to attract migrants, whereas economically depressed areas force people to move out.
- Physical factors: man seeks to avoid whatever makes him uncomfortable. In this regards, harsh climates like the cold and rid regions and rugged areas force people to migrate. By contrast, areas with favourable environmental conditions attract migrants.
- Natural disaster: natural disasters such as earthquakes, volcanic eruptions, flood, drought, famine and diseases epidemies forces people to migrate. By contrast, areas without cases of environmental disasters attract people.
- Socio-cultural factors: situations like political instability, social unrest and civil wars cause great population movements out of the affected areas. However, areas with stable and peaceful government attract migrant.
The availability of amenities and infrastructural facilities in an area attracts migrants, while poorly developed areas with little or no facilities encourage people to move out.
Effects of Migration
it is said that whatsoever is practiced has its effects be it positive or negation. The effects of migration are categorized into two; effects on the source region and effects on the receiving region.
Positive effects of migration on the source region
- It reduces pressure on the land and amenities.
- It enhances the spread of new ideas, techniques and innovations from other areas.
- It helps in the remittance of money back home by migrants and returning migrants.
Negative effects of migration on the source region
- It leads to loss of able-bodied to other areas, especially young men.
- Social and economic decline of places left.
- General depopulation of the region.
- High cost of living and as a result leads to poverty
- Lack of social amenities and facilities.
Positive effects of migration on the receiving region
- Access to abundant, cheap labour.
- Increased market, for food and industrial products.
- Promotion of inter-regional trade and transport.
- More diversified and cosmopolitan population.
- Greater interaction and generation of new ideas, techniques and innovations.
- Higher income from house rents, taxes etc.
Negative effects of migration on the receiving region
- Overcrowding: evident in housing congestion, traffic congestion.
- Insufficient and over-stretched social amenities.
- Deterioration in environmental sanitation.
- Increased incidence of epidemic diseases.
- Rise in crime wave, drug addiction, prostitution and other social ills.
- Poor distribution of resources.
- Uncontrolled rural-urban migration.
Climate can be defined as the average weather condition of a place measured over a long period of time. This phenomenon is governed by latitude, position relative to continents and ocean as well as the local geographical condition. The elements of climate are: temperature, rainfall, atmospheric pressure, humidity, wind, sunshine and clouds. Today, the climate has become a factor as to why people migrate from one place to another.
Classification of Climates
Climate is in various forms and its classification a conscious attempt of bringing together all the different climatic types with similar attributes. The reason for this classification is because climates in various regions or places vary from one place place to another. There are two forms of classification of climates as demonstrated by the Greek scholars and Koppen.
The Greek classification of climate
The Greek classification of climate is one of the earliest methods adopted by the Greek scholars to bring climate with similar attributes together based on temperature. In this method adopted, climate is simply divided according to the hemisphere into three broad areas namely:
- The tropic or torrid zone: this area occurs in the tropical lands. It has high temperature throughout the year.
- The mid-latitude or temperate zone: this area lies between the tropics and the polar regions. Here, temperature is mild or moderate and it has a seasonal contrast in temperature.
- The polar region or frigid zone: this is found within the Arctic and Antarctic regions of the world. This zone is generally believed to be very cold because of low temperature throughout the year.
The Greek classification of climate, though it was clear and concise, it has some disadvantages. The major disadvantage of this classification is that it only lays emphasis on temperature leaving out some climatic factors. The method of classification is very subjective and obsolete in modern times.
Koppen’s classification of climate
This classification was done by Dr. Wladimir Koppen of the university of Graz in Austria in 1918. He studied the Greek classification of climate and came out with a more unique classification on the basis of temperature and rainfall. Based on his studies, he identified five major climatic types which correspond with five principal vegetation belts.
- Tropical rainy climate: in this zone, the temperature is about 21 degrees and above. it is known for having heavy rainfall and the climate is usually moist.
- Dry climate: this zone has no month with temperature less than 6 degrees. It has lesser or no rainfall hence; it is referred to as desert.
- Warm temperate rainy climate: this climate has five months with temperature less that 6 degrees. It has a summer drought and a winter rain.
- Cool temperature snow forest: this zone is known to be cold and has the average temperature of the coldest month to be below -3 degrees. It has more than six months with temperature less than 6 degrees which implies that it has several months of snow cover.
- Polar climate: this as the name implies, is the ice or snow climate. There is no warm season in zones with this climate
Advantages of Koppen’s classification of climate
- The classification of Dr. Koppen is very objective
- It is quite easy to understand
- It is scientific since it uses real temperature and rainfall figures to arrive at different climatic types
- It could be used as educational aid.
- Disadvantages of Koppen’s classification of climate
- It is a bit confusing for people who are not knowledgeable in the field.
- He omitted the climates of highlands in the course of his analysis.
There is no marked distinction between one climate and the other.
Having explained these two theories of climate, I will say that, the forms of climate as postulated by scholars are not the conventional one or the upheld by the modern world. We have five types of climates in the world. These types of climate is in a way in line with the five continents of the world. They are: cold climate, cool temperate climate, warm climate, hot climate, desert climate.
Climate change can be said to be the irregularity of the climate due to the depletion of the ozone layer. For instance, when the rays of the sun come the earth, it is absorbed by trees for they feed from sunlight. Then, imagine when there are no more trees in a region of the earth, the rays remain and therefore causing the earth to become warm or hot. This brings about the change in climate because it causes imbalance to nature. Nature has setup its activity in a sense that any function at all has its opposite and equal reaction. But when one of these processes is hampered, then it creates a dangerous phenomenon.
Another example to explain climate change better is on the polar region and the increase of the sea level. When the earth becomes too hot, the polar region known to be cold gets warm and then the ice begins to melt and that increases the water level in the ocean there by making water level of lands to rise beyond its normal range. This leads to flood and flood brings forth disasters like destruction of bridges, houses, and valuables most especially lives. The question here is, how does climate change affect migration?
Consequences of climate change and how it affects migration
- The rising Sea level: it has been noticed in the 20th century that the sea level rose about 15 cm (6 inches) due to melting glacier ice and expansion of warmer seawater. Specialists have predicted that sea level may rise as much as 59 cm (23 inches) during the 21st Century, threatening coastal communities, wetlands, and coral reefs. This if occurred, may force habitants of the coastal lands to move to another area to avoid the risk and danger it causes. The major danger this situation can cause is flood, which may damage lives and properties. It can also prevent crops from germinating as they should.
- The melting of Arctic sea ice: analyses have shown that the summer thickness of sea ice is about half of what it was in 1950. The melting ice could lead to changes in ocean circulation, and the sea ice speeds up warming in the Arctic. As experienced in Nigeria and Cameroon in 2011, when the circulation of the ocean changes, it is discovered that countries big rivers will be affected. The ocean seeks to empty its water to gain balance and so sends water to other sources like the big rivers. If the rivers become too full, they tend to cause havoc on the inhabitants of the area. Hence, the people are forced to migrate from that area to another place. People also migrate because if the ocean gets too warm, those who find it hard to adapt migrate from the place too.
- Glaciers and permafrost are melting: for the past 100 years, mountain glaciers in all areas of the world have decreased in size and so has the amount of permafrost in the Arctic. Greenland’s ice sheet is melting faster, too. This is quite alarming because it can be a cause of danger and risks.
- Sea-surface temperatures are warming: as the temperature of the sea surface gets warmer, the warmer waters in the shallow oceans have contributed to the death of about a quarter of the world’s coral reefs in the last few decades. Many of the coral animals died after being weakened by bleaching, a process tied to warmed waters. People who feed or earn a living from these corals may tend to abandon the place in search for another work or mode of earning a living.
- The temperatures of large lakes are warming. The temperatures of large lakes world-wide have risen dramatically. Temperature rises have increased algal blooms in lakes, provided favorable conditions for invasive species, increased stratification in lakes, and lowered water levels in lakes. The farmers in places or countries who do not have access to the sea may suffer from this decrease in the water level in the lakes and so migrate elsewhere or to places with enough water to support their crops to continue their farming activities.
- Heavier rainfall cause flooding in many regions. The quantity of rainfall has increased as a result of warmer temperatures. The warm temperature has led to more intense rainfall events in some place. This is the main cause of flood in many countries. When the rainfall becomes too heavy, crops do not germinate properly and when this happens, there is low production of food which leads to hunger and starvation in some areas with large population. The people living in these areas may migrate to run away from the situation and seek for a favourable area and healthy ones.
- Drought is on the increase to the extreme: just like the case in Somalia, the issue of drought is becoming unbearable. This is because the higher temperatures cause a higher rate of evaporation and this leads to more drought in some areas of the world. Drought brings with it hunger, starvation and death. It is not supportable, hence, people in the area stricken by drought migrate to areas with conducive weather condition to survive.
- Crops no longer support lands: we hear farmers complaining of the withering of certain crops due to increased temperatures and, extreme droughts are causing a decline in crop productivity around the world. Decreased crop productivity can mean food shortages, which have many social implications; therefore, a strong determinant of migration.
- The change occurring in the Ecosystems: it is obvious that as temperatures get warm, species may either move to a cooler habitat or die and so, many species are going extinct. Species that are particularly vulnerable include endangered species, coral reefs, and polar animals can no longer withstand the situation. The warming has also caused changes in the timing of spring events and the length of the growing season.
- The change in the frequency and strength of Hurricanes. As experienced of recent in the united states of America, there is evidence that the number of intense hurricanes has increased in the Atlantic since 1970. Scientists continue to study whether climate is the cause. Due to the damage it causes, people are compelled to migrate from those places prone to its effects to another place.
- More frequent heat waves. It is likely that heat waves have become more common in more areas of the world. This has to do with adaptation too. Those who cannot adapt move on to dwell in another place conducive to their living.
- Warmer temperatures affect human health. There have been more deaths due to heat waves and more allergy attacks as the pollen season grows longer. There have also been some changes in the ranges of animals like mosquitoes that carry disease.
- Seawater is becoming more acidic. Carbon dioxide dissolving into the oceans is making seawater more acidic. This could cause impacts on coral reefs and other marine life.
This work has tried to explain the global view of what migration, climate and climate change, how it is understood and its consequences. It has also identified the types, its causes and its influence on people and countries respectively.
It could be deduced from the ideas presented in this work that, migration and climate change are more connected even though there are many reasons for migration such as push and pull effect. Those countries endowed with these resources possess the pull force and so the citizens of other countries who lack these resources are pushed out and attracted to the endowed countries. However, we cannot ignore that climate change also play a vital role in this matter.
Hence, I opine that migration and climate change is a problem today, but at the same time a blessing; for it brings diversity to our world. It makes us to meet and work with people from other countries or nation.
- Gregory white, Climate change and migration : security and borders in a warming world, 25.
- O. Areola, M. Mamman, F. A. On weluzo and O. Omotoso, Exam Focus Geography for WASSCE and JME, Ibadan: University Press Plc, 1999. Pp 125-126.
- Ogieva Erebor, Comprehensive Agricultural Science for Senior Secondary Schools, Lagos: A. johnson Publishers Limited, 2003. P. 29.
- Peter Oluwafemi S. Ajayi, Comprehensive Geography for Senior Secondary Schools, Lagos: A. Johnson Publishers Limited, 1998. Pp. 205-225.
- See Piguet, Pecoud and Guchteneire, Migration and Climate change,160 ff.