Climatic changes refer to variations in Earth’s global climate or in regions, over a period of time. It describes changes
in the variability average state of the atmosphere or average weather over time scales ranging from decades to millions of years. These may be due to internal farces, external or most recently be caused by human activities. In recent usage, especially in the context of environmental policy, the term "climate change" is often used to refer only to the ongoing changes in modern climate, including the average rise in surface temperature known as global warming.
The main factors causing climatic changes are:
1. Variations within Earth’s Climate: It is observed that climate is fiarly stable in nature which includes the average temperature, amount of precipitation, days of sunlight, and many other variables that might be measured at any given site. But there are chnages within the Earth’s environment that can brings chaines in Climate. They are Glaciation, Ocean variability and Internal variability in climatic conditions.
Glaciation: This includes the average temperature, amount of precipitation, days of sunlight, and many other variables that might be measured at any given site. For the last century, however, glaciers have been unable to regenerate enough ice during the winters in order to account for the ice lost during the summer months.
Ocean Variability: On the scale of mere decades, climate changes can also result from changes within the ocean/atmosphere systems.
Internal vairability:
a decade of dry conditions may cause lakes to shrink, plains to dry up and deserts to expand. In turn, these conditions may lead to less rainfall in the following years.
2. Non-climate factors driving climate change: They include the Greenhouse gaes, Solar variations, Volanoes, Orbital variations.
3. Human Factors: Anthropogenic factors are acts by humans that change the environment and influence climate. The biggest factor of present concern is increase in carbon-dioxide levels. Industrialization, globalization, land use, irrigation, agriculture, deforestation have caused the level of Carbon-dioxide to grow.
Climate changes can be seen in the form of little Ice Age, medieval warm periods, temperature record of last 1000 years and global warming.
Man needs to be careful!