Climate Change

Often in newspapers, television, and in magazines, we come across the term 'Climate Change' and it has been recognized as a global problem. Scientists are of the view that due to excessive emission of greenhouse gases, heat entrapment is taking place, which is causing rise in temperature. In this post I would like to share the different causes and evidences of climate change.

The earth's climate is dynamic and always changing through a natural cycle. What the world is more worried about is that the changes that are occurring today have been speeded up because of man's activities. Scientists across the globe are looking into these changes. Their findings are based on evidence from tree rings, pollen samples, ice cores, and sea sediments. The causes of climate change can be divided into two categories - those that are due to natural causes and those that are created by man.

Natural causes

There are a number of natural factors responsible for climate change. Some of the more prominent ones are continental drift, volcanoes, ocean currents, the earth's tilt, and comets and meteorites. Let's look at them in a little detail.

Continental Drift:Millions of years back the continents that we are familiar with today were formed when the landmass began gradually drifting apart. This drifting of the landmasses impacted on the climate as it has changed the physical features of the landmass, their position and the position of water bodies. Moreover, the separation of the landmasses changed the flow of ocean currents and winds that in turn affected the climate.

Volcanoes: Volcanoes are also responsible for climate change. When a volcano erupts it throws out large volumes of sulphur dioxide, water vapour, dust, and other particles into the atmosphere, which in turn increase the temperature.

Ocean Currents:Oceans are the most important natural cause for climate change. They cover a huge portion of the earth, around 71%, therefore, they absorb about twice as much of the sun's radiation as the atmosphere or the land surface. Ocean currents move a huge amount of heat across the planet, approximately the same amount as the atmosphere does.

Man-made Causes

In our daily lives, we contribute a bit to this change in the climate. Let’s see some of them:
• In urban areas, electricity is the main source of power, most of our gadgets run on electricity. This electricity is generated mainly from thermal power plants. These plants are run on fossil fuels mostly coal and are responsible for the emission of huge amounts of greenhouse gases and other pollutants.
• Human beings have discovered automobiles, which run mainly on petrol or diesel. Both petrol and diesel are fossil fuels and as they are burnt, green house gases are released in the atmosphere.
• Large quantities of waste in the form of plastics that remain in the environment for several years and cause environmental degradation.
• Deforestation is another cause for climate change. We are cutting down forests in large scales for construction of houses.

Evidences of Climate Change

Glaciers are one of the most sensitive indicators of climate change. Since 1970s, a world glacier inventory has been combined, initially based mainly on aerial photographs and maps but currently it is relying more on satellites. This compilation, tracks several glaciers and estimated that the remaining ice cover is around 445,000 km2. Thus it can be concluded that the glaciers worldwide have been found to be shrinking significantly.

Change in climate also affects the coverage of vegetation A mild change in climate sometimes results either in improved plant growth or rapid plant loss and desertification in certain circumstances.

It is the analysis of tree ring growth patterns to determine past climate variations. Wide and thick rings indicate a fertile, well-watered growing period, whilst thin, narrow rings indicate a time of lower rainfall and less-than-ideal growing conditions.