Major Causes of Climate Change

As previously stated, causes of climate change can be categorized in two. The natural and human causes. Let us take a look on each of them.

Natural Causes or Contributors

Some of the major contributors on these natural causes are continental drift, volcanoes, ocean currents, the earth's tilt, and comets and meteorites.

This drift also had an impact on the climate because it changed the physical features of the landmass, their position and the position of water bodies. The separation of the landmasses changed the flow of ocean currents and winds, which affected the climate.

Volcano Eruptions
When a volcano erupts it throws out large volumes of sulphur dioxide (SO2), water vapour, dust, and ash into the atmosphere. Millions of tones of sulphur dioxide gas can reach the upper levels of the atmosphere (called the stratosphere) from a major eruption. The gases and dust particles partially block the incoming rays of the sun, leading to cooling. Sulphur dioxide combines with water to form tiny droplets of sulphuric acid. Movement of aerosols north and south is always much slower.

As an example, Mount Pinatubo, in the Philippine islands erupted in April 1991 emitting thousands of tones of gases into the atmosphere. Volcanic eruptions of this magnitude can reduce the amount of solar radiation reaching the Earth's surface, lowering temperatures in the lower levels of the atmosphere (called the troposphere), and changing atmospheric circulation patterns. Significant weather-related disruptions occurred in New England and in Western Europe with killing summer frosts in the United States and Canada.

Earth's Movement
The earth makes one full orbit around the sun each year. In the other half when it is winter, the earth is tilted away from the sun. Changes in the tilt of the earth can affect the severity of the seasons - more tilt means warmer summers and colder winters; less tilt means cooler summers and milder winters.

Body of Water Currents
The oceans are a major component of the climate system. They cover about 71% of the Earth and absorb about twice as much of the sun's radiation as the atmosphere or the land surface.

Winds push horizontally against the sea surface and drive ocean current patterns.
Certain parts of the world are influenced by ocean currents more than others. The coast of Peru and other adjoining regions are directly influenced by the Humboldt current that flows along the coastline of Peru. The El Niño event in the Pacific Ocean can affect climatic conditions all over the world.

Another region that is strongly influenced by ocean currents is the North Atlantic. If we compare places at the same latitude in Europe and North America the effect is immediately obvious. The rest of the Arctic Ocean, even though it is much further south, remains frozen.

Human causes

The Greenhouse Effect
Carbon dioxide is undoubtedly, the most important greenhouse gas in the atmosphere. Changes in land use pattern, deforestation, land clearing, agriculture, and other activities have all led to a rise in the emission of carbon dioxide.

Methane is another important greenhouse gas in the atmosphere. Methane is also released from rice or paddy fields that are flooded during the sowing and maturing periods. When soil is covered with water it becomes anaerobic or lacking in oxygen. Under such conditions, methane-producing bacteria and other organisms decompose organic matter in the soil to form methane. China and India, between them, have 80-90% of the world's rice-growing areas.

Humans Daily Contributions
All of us in our daily lives contribute our bit to this change in the climate. All our gadgets run on electricity generated mainly from thermal power plants. These thermal power plants are run on fossil fuels (mostly coal) and are responsible for the emission of huge amounts of greenhouse gases and other pollutants.

- We generate large quantities of waste in the form of plastics that remain in the environment for many years and cause damage.
- Timber is used in large quantities for construction of houses, which means that large areas of forest have to be cut down.

Because the land area available for agriculture is limited (and in fact, is actually shrinking as a result of ecological degradation!), high-yielding varieties of crop are being grown to increase the agricultural output from a given area of land. Pollution also results from the run-off of fertilizer into water bodies.

We must act now to be able to limit and decrease this climate change causes. I know we can’t stop the natural ones but the human causes; I think we can do something about it. Besides, we humans are the high contributors and will be highly affected by this climate change.