Climate change defined as: “Long term weather patterns and trends becoming different over an extended period of time”
For example if the average temperature in Pakistan over the 20th century is significantly higher or lower than the average temperature in Pakistan over the 19th century this would be an example of climate change.
Global warming and climate change in reality the two terms means different things have both been used for decades. Climate change again as the name suggest, refers to the changes in global climate which result from increasing average global temperature. For example changes in precipitation patterns, increased prevalence of drought, heat waves and other extreme weather etc. In general there are 10 indicators with the help of which we can detect climate change and global warming. There are 7 indicators that would be expected to increase in a warming world and 3 indicators would be expected to decrease.
Changes in climate can result from both natural events and human activities. Examples for natural events are volcanic eruptions, variation in earth’s orbit around sun and variation in solar output. Examples for human induced causes are industrial pollutant and fossil fuels, warming of average annual temperature due to urbanization and changes in earth’s albedo due to deforestation of tropical rainforest.
Earth temperature depends on the balance between energy entering and leaving the planet’s system. When incoming energy from the sun is absorbed by earth system, Earth warms when energy is reflected back into the space. Earth avoids warming when energy is released back into the space. Earth cools many factors both natural and human can cause changes in earth’s energy balance.
Our lives are connected to the climate. Human societies have adapted to the relatively stable climate we have enjoyed since the last ice age which ended several thousand years ago. A warming climate will bring changes that can affect our water supplies, power and transportation system, natural experiments and even our own health and safety. Carbon dioxide can stay in atmosphere for nearly a century so earth will continue to warm in coming decades. The warmer it gets, the greater the risk for more severe changes to climate and earth’s system. It is difficult to predict the exact impacts of climate change.