It has been said that “climate is what you expect and weather is what you get”. Climate change refers to a gradual shift in the overall weather occurrences associated with an increase in global average temperatures. Basically, it is the long-term shift in average weather patterns across the world. Since the mid-1800s, humans have contributed to an excessive release of carbon dioxide and other greenhouse gases into the air, causing global temperatures to rise which has resulted in persistent changes to the climate.
Changes in the earth’s climate, due to human activities — also known as anthropogenic climate change — include increasing air and sea surface temperatures, changing rainfall patterns, ocean acidification, sea-level rise and changes in frequency and intensity of extreme events like floods, droughts and tropical cyclones.
Difference between global warming and climate change
These terms are often used interchangeably but have different meanings. Global warming is just one of the many aspects of climate change. The term ‘global warming’ refers to the recent rise in the global average temperature near the earth’s surface which is caused mostly by increasing concentrations of greenhouse gases (such as carbon dioxide and methane) in the atmosphere.
Climate change effects
Extreme weather conditions: Changes in precipitation patterns, including extreme precipitation events like storms and floods are becoming more severe and frequent in many regions, and this is expected to continue.
Droughts: Rising temperatures lead to increased rates of evaporation and can cause more rapid drying of soils. Without a reduction in global greenhouse gas emissions, longer-term droughts are expected to intensify in much of the Southwest, the Great Plains, and the Southeast.
Rising ocean levels: Rising temperatures are causing glaciers and ice sheets to melt, adding more water to the oceans and causing the ocean level to rise. Oceans absorb 90 per cent of the extra heat from global warming, so warmer water expands, and our oceans occupy more space.
Ocean acidification: It occurs when the ocean absorbs carbon dioxide and becomes more acidic. It is often called the ‘evil twin’ of the climate change.
Impact on health: Climate change is increasing mankind’s exposure to extreme temperatures, weather events, degraded air quality, diseases transmitted through food, water, and insects, and stresses to mental health and well-being. These threats to human health are expected to increase with continued and unchecked climate change.